MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Journal of Biomaterials Applications' source. Thu, 18 Mar 2010 16:59:39 +0100 http://www.medworm.com/index.php?rid=3243635&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F6%2F555%3Frss%3D1 In this study, four invert PBG formulations (in the system P2O5—CaO—MgO—Na 2O) were produced with fixed phosphate and calcium content at 40 and 25 mol%, respectively. MgO was added at 10—30 mol% in place of Na 2O and the maximum divalent cation to phosphate ratio obtained was 1.375. Thermal analyses showed a linear increase in Tg with increasing MgO content. This was proposed to be due to an increase in the cross-link density of the glass network, which also improved the chemical durability of the glass. EDX analyses were also conducted to verify the final composition of the glass. XRD analyses confirmed the amorphous nature of the glasses investigated. Rapid quenching of the Mg30 glass revealed a degree of surface crystallization, which was shown to be a CaMgP2O7 p... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=3243635 Thu, 04 Feb 2010 17:13:41 +0100 3243635 http://www.medworm.com/index.php?rid=3243634&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F6%2F545%3Frss%3D1 In this study, using a rat model, the effectiveness of chitosan hydrogel as an intestinal fistula repair agent was investigated. Twenty rats underwent laparotomy under general anesthesia. The antimesentric portion of the cecum was incised (1 cm) and sutured to the abdominal wall. Chitosan hydrogel was applied daily to the fistula until it was completely closed. Blood samples taken from all animals were analyzed. After sacrifice, the cecum was removed and histopathologic investigation was performed. Spontaneous closure of the intestinal fistula was observed in all animals for both the control and chitosan hydrogel groups. Healing in the chitosan hydrogel group healing was faster than that in the control group. Blood analysis revealed significant differences between the chitosan hydrogel and... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=3243634 Thu, 04 Feb 2010 17:13:41 +0100 3243634 http://www.medworm.com/index.php?rid=3243633&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F6%2F527%3Frss%3D1 Poly (ethylene terephthalate) (PET) was surface modified by plasma polymerization of acetobromo--D-glucose (ABG) at different radio frequency (RF) powers. Plasma polymerization was carried out by vaporizing ABG in the powder form by heating at 135°C. Surface modification resulted in improved hydrophilicity and smoothness of the surface especially at low RF powers (30—50 W), but at high RF powers, the surface was found to be etched and the hydrophilicity decreased as evidenced by atomic force microscopy (AFM) and contact angle measurements. The plasma polymerized ABG film was found to be extensively cross-linked as evidenced by its insolubility in water. Infra red (IR) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the plasma polymerized ABG films. IR stu... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=3243633 Thu, 04 Feb 2010 17:13:41 +0100 3243633 http://www.medworm.com/index.php?rid=3243632&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F6%2F503%3Frss%3D1 A series of cellulose/soy protein isolate (SPI) sponges was prepared using a freeze-drying process. The effect of the SPI content on the structure of the sponges was characterized by Fourier transform infrared spectrometry (FT-IR), X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). It showed that the sponges were porous in structure, and that the size of the pores increased and the thickness of the pore walls decreased as the SPI content of the sponges increased. The biocompatibility and biodegradability of the sponges were evaluated in vitro and in vivo. The cell culture experiment and SEM observations showed that L929 fibroblast cells grew and spread well on the surface and cross-section of the composite sponges. The results from MTT (3-[4,5-dimethyl-2-thiazoly1]-2,... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=3243632 Thu, 04 Feb 2010 17:13:41 +0100 3243632 http://www.medworm.com/index.php?rid=3243631&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F6%2F483%3Frss%3D1 In this study GPCs based on Sr-Ca-Zn-SiO 2 glasses and low molecular weight PAA were evaluated for orthopaedic luting applications. GPCs based on four different glasses; BT100 (0.16CaO, 0.36ZnO, 0.48SiO2), BT101 (0.04SrO, 0.12CaO, 0.36ZnO, 0.48SiO 2), BT102 (0.08SrO 0.08CaO, 0.36ZnO, 0.48SiO2) and BT103 (0.12SrO 0.04CaO, 0.36ZnO, 0.48SiO2) and two PAAs (MW; 12,700 and 25,700) were examined. These cement formulations exhibited handling properties potentially suitable for luting applications as well as mechanical strengths which were similar to those of trabecular bone. Upon immersion in simulated body fluid, the GPCs showed sustained growth of a calcium phosphate layer on the surface of the cement indicating that these cements were bioactive in nature. (Source: Journal of Biomaterials Appli... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=3243631 Thu, 04 Feb 2010 17:13:41 +0100 3243631 http://www.medworm.com/index.php?rid=3243641&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Freprint%2F24%2F5%2F475%3Frss%3D1 (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=3243641 Thu, 04 Feb 2010 17:00:37 +0100 3243641 http://www.medworm.com/index.php?rid=3243640&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F5%2F453%3Frss%3D1 Resin luting agents in which bisphenol-A glycidyl dimethacrylate (Bis-GMA) and/or triethylene glycol dimethacrylate (TEGDMA) are replaced with increasing amounts of bisphenol-A ethoxylated dimethacrylate are prepared. Degree of conversion (DC), diametral tensile strength (DTS), Young’s modulus (YM), Knoop hardness (KHN), film thickness (FT), water sorption (Wsp ), and solubility are evaluated. Regression analyses investigate the substitution of each monomer. The most appreciable differences are detected when TEGDMA is replaced: decreased DC, DTS, and Wsp, and increased YM, KHN, and FT. For substitution of Bis-GMA, the only significant differences are reduced Wsp and increased YM. An ideal formulation of resin cement would make use of the three monomers. (Source: Journal of Biomateria... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=3243640 Thu, 04 Feb 2010 17:00:37 +0100 3243640 http://www.medworm.com/index.php?rid=3243639&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F5%2F437%3Frss%3D1 This study evaluates the influence of polymer coatings on human aortic endothelial cells (HAEC) and coronary artery smooth muscle cells (HCASMC) in vitro, in terms of morphology, cell number, and phenotype. It was demonstrated that the polymer coatings can be tailored to enhance adhesion and growth of HAECs whilst suppressing that of HCASMCs. It is concluded that one of the polymer coatings (BTL 01015) shows potential as a stent coating to enhance re-endothelialization. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=3243639 Thu, 04 Feb 2010 17:00:37 +0100 3243639 http://www.medworm.com/index.php?rid=3243638&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F5%2F419%3Frss%3D1 We have developed a novel glass-ionomer cement system composed of multi-arm poly(acrylic acid-co-itaconic acid)s. These polyacids were synthesized via a chain-transfer polymerization reaction using newly synthesized multi-arm chain-transfer agents. The cements formulated with the multi-arm polyacids showed significantly lower viscosities in water as compared to those formulated with the linear polyacids. Due to the lower viscosities, the MW of the polyacids can be significantly increased for enhanced mechanical strengths, while keeping the ease of mixing and handling. The experimental cements showed significantly improved compressive strengths as compared to Fuji II after aged in water for 3 months. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=3243638 Thu, 04 Feb 2010 17:00:37 +0100 3243638 http://www.medworm.com/index.php?rid=3243637&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F5%2F401%3Frss%3D1 Porous scaffolds play an integral role in many tissue-engineering approaches, and the ability to improve vascularization, without eliciting an excessive inflammatory response, would constitute an important step towards achieving long-term healing and function of devices made from these materials. After having previously optimized the dimensional requirements of the well-defined pores, the present study aimed at a further shift from inflammation to vascularization via surface immobilization with heparin. Porous polyurethane disks were produced to contain well-defined pores (147 ± 2 µm) with abundant interconnecting windows (67 ± 2 µm). After heparinization via copolymer grafting and amination to contain 32 µg of heparin, the modification appeared as a uniform... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=3243637 Thu, 04 Feb 2010 17:00:37 +0100 3243637 http://www.medworm.com/index.php?rid=3243636&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F5%2F387%3Frss%3D1 Allograft tissues are used in over one million musculoskeletal procedures per year. Consequently, it is crucial tissue banks use procedures to militate against allograft associated bacterial and viral infections. Recent studies have identified an important pathogen inactivation technology for musculoskeletal allografts that utilizes high-dose gamma irradiation (50 kGy) under controlled conditions. A total dose of 50 kGy assures that the current standard for medical devices for a microbial sterility assurance level of 10— 6 is met. Furthermore, the pathogen inactivation technology results in a greater than four log inactivation of enveloped and nonenveloped viruses. Efficacious clinical outcome from musculoskeletal allografts exposed to this innovative sterilization procedure will req... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=3243636 Thu, 04 Feb 2010 17:00:37 +0100 3243636 http://www.medworm.com/index.php?rid=2920096&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F4%2F353%3Frss%3D1 The aim of the present work is the synthesis and characterization of polymer materials showing good adhesion, drug loading, and delivery properties, for potential cardiovascular application. In particular, poly(methylmethacrylate-co-acrylic acid) copolymers are prepared in different compositions by a radical polymerization and investigated as potential materials to coat metallic stents and to carry out a local drug release. Films obtained by dissolving the copolymer in an appropriate organic solvent (also loaded with an anti-restenosis drug, such as tacrolimus) are investigated: physicochemical properties, adhesiveness to metallic stent material, and kinetics of drug release in physiological environment are studied. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2920096 Fri, 23 Oct 2009 11:11:35 +0100 2920096 http://www.medworm.com/index.php?rid=2920095&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F4%2F343%3Frss%3D1 This study concludes that an 8-h cryoprotectant incubation time is detrimental to qualitative allogeniec tibialis posterior tendon properties. Both groups tended to improve with longer rehydration times, however the 8-h incubation group remained actively dehydrated as evidenced by its smaller diameter and poorer tissue handling properties. Suboptimally rehydrated tendons would be more likely to accrue damage during allograft preparation or during implantation. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2920095 Fri, 23 Oct 2009 11:11:35 +0100 2920095 http://www.medworm.com/index.php?rid=2920094&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F4%2F327%3Frss%3D1 We examine the osteogenicity of a sponge biomaterial consisting of a biodegradable mixture of gelatin and β-tricalcium phosphate (βTCP) that bound bone morphogenetic protein 2 (BMP-2) in critical-sized bone defects in rats. Gelatin-βTCP sponges containing either phosphate buffered saline or incorporating BMP-2 are implanted into 5 mm diameter bone defects created in rat mandibles. We assess the defects biweekly for 8 weeks following implantation. There is significantly higher osteoinductive activity and significantly more Gla-osteocalcin content at bone-defect healing sites treated with gelatin-βTCP sponges incorporating BMP-2 than there is in those treated with sponges that did not contain BMP-2. Histologically, new bone that contains bone marrow and that is connected ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2920094 Fri, 23 Oct 2009 11:11:35 +0100 2920094 http://www.medworm.com/index.php?rid=2920093&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F4%2F309%3Frss%3D1 PLGA and PLA microparticles entrapping insulin are prepared by solvent evaporation method and are evaluated in diabetes-induced rat for its efficacy in maintaining blood sugar level from a single intramuscular dose. In vitro release of insulin from PLGA and PLA microparticles are 75.35 ± 1.73% and 67.536 ± 2.23%, respectively in 168 h (7 days). Released insulin from polymer particles are mostly in monomeric form without aggregation. Optimal use of stabilizers during particle formulation helps in reducing protein denaturation and thus results in stabilized insulin-loaded polymer particles. Intramuscular administration of insulin-loaded PLGA (50 : 50) and PLA microparticles (equivalent to 25 IU insulin/kg of animal weight) in alloxaninduced diabetic rats result in 53.86 &plusmn... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2920093 Fri, 23 Oct 2009 11:11:35 +0100 2920093 http://www.medworm.com/index.php?rid=2920092&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F4%2F293%3Frss%3D1 The role of aluminum in glass-ionomers and resin-modified glass-ionomers for dentistry is reviewed. Aluminum is included in the glass component of these materials in the form of Al2O3 to confer basicity on the glass and enable the glass to take part in the acid—base setting reactions. Results of studies of these reactions by FTIR and magic-angle spinning (MAS)-NMR spectroscopy are reported and the role of aluminum is discussed in detail. Aluminum has been shown to be present in the glasses in predominantly 4-coordination, as well as 5- and 6-coordination, and during setting a proportion of this is converted to 6-coordinate species within the matrix of the cement. Despite this, mature cements may contain detectable amounts of both 4- and 5-coordinate aluminum. Aluminum has been found ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2920092 Fri, 23 Oct 2009 11:11:34 +0100 2920092 http://www.medworm.com/index.php?rid=2765888&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F3%2F275%3Frss%3D1 The objective of this study is to report the effect of Pluronic F-127 on osteoblast viability and phenotype maintenance in vitro. MG-63 cells are suspended in Pluronic F-127, and MTT assay, alkaline phosphatase activity, prostaglandin E2 production, collagen-I, and cyclo-oxygenase-2 expression are assessed up to 6 days. Pluronic F-127 leads to a significant decrease in osteoblast viability throughout the 6-day experiment, without altering osteoblast phenotype. The addition of platelet-rich plasma to the polymer/cell construct leads to increased cell survival. When supplemented with bioactive factors, Pluronic F-127 could potentially be used as a cell carrier in bone tissue engineering. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2765888 Thu, 03 Sep 2009 23:00:00 +0100 2765888 http://www.medworm.com/index.php?rid=2765887&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F3%2F247%3Frss%3D1 The purpose of this study is the development of a nerve electrode that reorganizes nerve geometry slowly and controllably. The Flat Interface Nerve Electrode (FINE) can reshape the nerve into an elongated oval and provide selective stimulation. However, the rate of closure of this electrode is difficult to control. The Slowly Closing - FINE (SC-FINE) is designed with an opening height larger than the size of the nerve to accommodate initial swelling. The electrode closes slowly to reshape the nerve into the desired flat geometry. The SC-FINE is created by combining the reshaping properties of the FINE and the controllable degradation of Poly (DL lactic-co-glycolic) acid (PLGA). Bonding 50/50 or 65/35 PLGA to a stretched FINE increased the opening heights (OH) on average from 0.1 mm to 1.66... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2765887 Thu, 03 Sep 2009 23:00:00 +0100 2765887 http://www.medworm.com/index.php?rid=2765886&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F3%2F231%3Frss%3D1 In this study, the effects of wollastonite on proliferation and differentiation of human bone marrow-derived stromal cells (hBMSCs) have been investigated based on a polyhydroxybutyrate-co-hydroxyvalerate (PHBV)/ wollastonite (W) composite scaffolds system. Cell morphology, proliferation, and differentiation were measured. The results showed that the incorporation of wollastonite benefited hBMSCs adhesion, proliferation, and differentiation rate. In addition, an increase of proliferation and differentiation rate was observed when the wollastonite content in the PHBV/W composite scaffolds increased from 10 to 20 wt%. Based on our previous studies on PHBV/W composite discs, the differentiation measurements in this paper further proved that the wollastonite itself can stimulate the hBMSCs to ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2765886 Thu, 03 Sep 2009 23:00:00 +0100 2765886 http://www.medworm.com/index.php?rid=2765885&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F3%2F209%3Frss%3D1 In this study, three chitosan/polycation composite membranes for guided bone regeneration are produced by blending chitosan with poly-L-lysine, polyethyleneimine, and poly-L-ornithine. For all composite membranes, the surface characteristics including surface topography, chemistry, and wettability are examined by atomic force microscopy, X-ray photoelectron spectroscopy, and contact angle assay. Their cytocompatibility is also evaluated with MC3T3-E1 osteoblast-like cells at cell, protein, and gene levels through cell biology assays, western blot, and RT-PCR analysis. On chitosan/poly-L-lysine composite membrane, MC3T3-E1 cells present well-developed cytoskeletal organization and significantly higher adhesion, proliferation, and differentiation than those on chitosan and the other two comp... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2765885 Thu, 03 Sep 2009 23:00:00 +0100 2765885 http://www.medworm.com/index.php?rid=2765884&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F3%2F197%3Frss%3D1 The objective of this work is to study the biochemical effect in liver and kidney 2, 14, and 28 days after applying different tissue adhesives. In a prospective longitudinal study, 20 adult rats are assigned to two groups. After making incisions in the buccal mucosa, n-butyl-2-cyanoacrylate is applied to the first group and 2-octyl-cyanoacrylate (OCA) to the second. The biochemical parameters studied are: albumin (ALB), alanine aminotrasferase (ALT), amylase (AMY), total bilirubin (TBI), blood urea nitrogen (BUN), creatinine (CRE), glucose, globulin, total proteins (TP), and the ions calcium, phosphorus, sodium, and potassium. The group treated with n-butyl-2-cyanoacrylate shows no statistically significant differences with respect to the control, but OCA produces statistically significant... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2765884 Thu, 03 Sep 2009 23:00:00 +0100 2765884 http://www.medworm.com/index.php?rid=2757614&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F2%2F175%3Frss%3D1 The objective of this study is to evaluate the suitability of a mouse middle ear model for testing ossicular replacement materials. Twenty-four BALB/c mice are implanted with the bioglass-ceramic Bioverit® II which is coated with a silica-nanostructure or with plain Bioverit® II as a control. After 2, 6, and 12 weeks, 4 mice per group are sacrificed and both complete petrous bones are analyzed histologically. All implants revealed in situ an incipient growth of thin connective tissue layers over the surface, followed by a spreading of epithelial cells. The osseogenic response which is increasing with time is more intense in the coated Bioverit ® II specimens. The absence of inflammatory cells suggests an excellent biocompatibility of the silica nano structure. As the results ar... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2757614 Tue, 01 Sep 2009 23:00:00 +0100 2757614 http://www.medworm.com/index.php?rid=2757613&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F2%2F159%3Frss%3D1 This study was conducted to determine if a novel cleaning process could extract antigenic material from bovine bone thereby improving incorporation. Cleaned bovine xenograft, untreated bovine xenograft and sheep allograft were implanted into the tibia of mature sheep for 12 and 24 weeks. Inflammation, bone integration and immunological reactions were evaluated via standardized assays. Cleaned bovine bone dowels induced significantly lower inflammatory responses (p<50.05) when compared to traditionally processed xenograft. Bone integration, measured by in situ biomechanics, was not different between cleaned bovine bone and allograft controls (p = 0.96). A transient antibody response was observed for non-treated xenografts although this response abated by 3 months. (Source: Journal of Bio... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2757613 Tue, 01 Sep 2009 23:00:00 +0100 2757613 http://www.medworm.com/index.php?rid=2757612&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F2%2F139%3Frss%3D1 CaSiO3 (CS) ceramics have been regarded as a potential bioactive material for bone regeneration. Mg2SiO4 (M2S) ceramic has been reported as a novel bioceramic with higher mechanical properties and good biocompatibility recently. β-Ca2(PO4) 2 (β-TCP) ceramic is a well-known bioactive and degradable material for bone repair. The aim of this study is to investigate and compare the effect of three bioceramics with different chemical composition on the in vitro degradation, apatite-forming ability in simulated body fluid (SBF) and cytocompatibility. The degradation was evaluated through the activation energy of Si or P ion released from ceramics and the weight loss of the ceramics in TrisHCl buffer solution. Formation of bone-like apatite on different bioceramic surfaces was investiga... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2757612 Tue, 01 Sep 2009 23:00:00 +0100 2757612 http://www.medworm.com/index.php?rid=2757611&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F2%2F119%3Frss%3D1 In order to improve the homogeneous dispersion of particles in the polymeric matrix, 45S5, mesoporous 58S, and 58S bioactive glasses were surface modified by esterification reactions with dodecyl alcohol at reflux temperature of 260°C (named as m-45S5, m-mesoporous 58S, and m-58S, respectively). The modified particles showed better hydrophobicity and longer time of suspension in organic matrix. The PDLLA/bioactive glass composite films were fabricated using surface modified bioactive glass particles through solvent casting-evaporation method. Surface morphology, mechanical property, and bioactivity were investigated. The results revealed that the inorganic particle distribution and tensile strength of the composite films with modified bioactive glass particles were significantly improv... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2757611 Tue, 01 Sep 2009 23:00:00 +0100 2757611 http://www.medworm.com/index.php?rid=2757610&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F2%2F105%3Frss%3D1 In this study, we fabricate bioactive composites in which polyetheretherketone is reinforced with 0—50 vol% 30CaO · 70SiO2 (CS) microspheres. The prepared composites reinforced with CS particles form hydroxyapatite on their surfaces in simulated body fluid. The induction periods of hydroxyapatite formation on the composites decrease with increasing amount of CS particles. The mechanical properties of the composites are evaluated by three-point bending test. The composites reinforced with 20 vol% CS particles show 123.5 MPa and 6.43 GPa in bending strength and Young’s modulus, respectively. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2757610 Tue, 01 Sep 2009 23:00:00 +0100 2757610 http://www.medworm.com/index.php?rid=2757609&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F2%2F89%3Frss%3D1 The aim of this study was to investigate the effect of C-Graft particles on formation of new cementum and bone in periodontal bone defects in dog. Healing and tissue change were histologically determined at 2, 4, 8, and 16 weeks. Little bone or cementum formation was observed in the control group. A statistically significant increase in bone and cementum formation was seen in the C-Graft group compared to the control group (75.4% vs. 44.9%, p<50.01, 80.4% vs. 46.7%, p<50.05, respectively). These findings suggest that C-Graft particles provide a scaffold for the regeneration of new bone and cementum. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2757609 Tue, 01 Sep 2009 23:00:00 +0100 2757609 http://www.medworm.com/index.php?rid=2552960&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F1%2F65%3Frss%3D1 Hydroxyapatite (HA) has been extensively investigated as scaffolds for tissue engineering, as drug delivery agents, as non-viral gene carriers, as prosthetic coatings, and composites. Recent studies in our laboratory demonstrated the immunoadjuvant properties of HA when administered with malarial merozoite surface protein-119 (MSP-119). HA nanoceramic carrier was prepared by co-precipitation method that comprises of sintering and spray-drying technique. Prepared systems were characterized for crystallinity, size, shape, and antigen loading efficiency. Small size and large surface area of prepared HA demonstrated good adsorption efficiency of immunogens. Prepared nanoceramic formulations also showed slower in vitro antigen release and slower biodegrability behavior, which may lead to a prol... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2552960 Sun, 28 Jun 2009 23:00:00 +0100 2552960 http://www.medworm.com/index.php?rid=2552959&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F1%2F47%3Frss%3D1 The present study was designed to assess and compare with a range of surfactant-coated, nimesulide-free, and nimesulide-loaded ethylcellulose/methylcellulose (EC/MC) nanoparticles that were prepared by varying drug concentration (ED/MD), polymer concentration (EP/MP), and surfactant concentration (ES/MS). EC/MC nanoparticles prepared by desolvation method produced discrete particles and they were characterized by SEM, AFM, and FTIR studies. The particles mean size diameter (nm) ranged from 244 to 1056 nm and 1065 to 1710 nm for EC and MC nanoparticles, respectively. Studies on drug: polymer ratio showed a linear relationship between drug concentration and percentage of loading in nanoparticles. The encapsulation efficiency decreased with the increase of nimesulide concentration with respec... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2552959 Sun, 28 Jun 2009 23:00:00 +0100 2552959 http://www.medworm.com/index.php?rid=2552958&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F1%2F31%3Frss%3D1 In this study, nano-hydroxyapatite (n-HA) combined polycarbonate was synthesized by a novel method. The physical and chemical property of the composite was tested. The results indicated the n-HA a crystal has the similar grain size, phase composition and crystal structure as. TEM photos results show the n-HA crystals were uniformly distributed in the polymer matrix. Then, the chemical bond between inorganic n-HA and polycarbonate was investigated and discussed. Proliferation of MSCs/composite cultured for up to 11 days the adhesion were tested by MTT and SEM. The in vitro test confirmed that the n-HA/PC composite was biocompatible and no negative effect on MSCs has found. The composite is proved to be osteoconductive, and can stimulate the growth of new bone. These results indicated that t... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2552958 Sun, 28 Jun 2009 23:00:00 +0100 2552958 http://www.medworm.com/index.php?rid=2552957&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F24%2F1%2F7%3Frss%3D1 Electrospinning has been employed extensively in tissue engineering to generate nanofibrous scaffolds from either natural or synthetic biodegradable polymers to simulate the cellular microenvironment. Electrospinning rapidly produces fibers of the nanolength scale and the process offers many opportunities to tailor the physical, chemical, and biological properties of a material for specific applications and cellular environments. There is growing evidence that nanofibers amplify certain biological responses such as contact guidance and differentiation, however this has not been fully exploited in tissue engineering. This review addresses the cellular interactions with electrospun scaffolds, with particular focus on neural, bone, cartilage, and vascular tissue regeneration. Some aspects of ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2552957 Sun, 28 Jun 2009 23:00:00 +0100 2552957 http://www.medworm.com/index.php?rid=2552956&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Freprint%2F24%2F1%2F5%3Frss%3D1 (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2552956 Sun, 28 Jun 2009 23:00:00 +0100 2552956 http://www.medworm.com/index.php?rid=2397846&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F6%2F561%3Frss%3D1 A range of calcium—strontium—zinc—silicate glass grafts are developed. Following characterization, their ability to form an apatite layer in simulated body fluid (SBF) is evaluated. Concurrently, their in vivo biocompatibility is determined. These glasses are incapable of forming an apatite layer in SBF. However, in vivo, each glass is well tolerated with new bone formation apparent in close apposition to implanted particles and no evidence of an inflammatory response. Such results are contrary to much of the literature and indicate that forecasting a materials ability to bond to bone based on SBF experiments may provide a false negative result. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2397846 Tue, 05 May 2009 04:00:00 +0100 2397846 http://www.medworm.com/index.php?rid=2397845&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F6%2F549%3Frss%3D1 Periodontal bone defects and atrophy of the jaws in an aging population are of special concern. Tissue engineering using embryonic stem cells (ESCs) and biomaterials may offer new therapeutic options. The purpose of this study is to evaluate the compatibility of ESCs with biomaterials and the influence of biomaterials on the osteogenic gene expression profile.Therefore, ESCs are cultured with various biomaterials. The cytocompatibility of murine ESCs is measured regarding the proliferation of the cells on the materials by CyQUANT ® assay, the morphology by scanning electron microscopy, and the influence on the gene expression by real time PCR.The results show that insoluble collagenous bone matrix, followed by β-tricalciump... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2397845 Tue, 05 May 2009 04:00:00 +0100 2397845 http://www.medworm.com/index.php?rid=2397844&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F6%2F533%3Frss%3D1 In this study, the mechanical properties and microenviroment of 3D printed poly-lactic-co-glycolic acid (PLGA) scaffolds are examined. Additionally, the proliferation and differentiation of human fetal osteoblasts are evaluated after 3 weeks of in vitro culture on the scaffolds. The results showed that the PLGA scaffolds examined had mechanical properties similar to that of trabecular bone, but was still much weaker compared to cortical bone. In addition to general porosity, the PLGA scaffolds also had micropores within macropore walls. Cultured human osteoblasts could proliferate upon seeding on the PLGA scaffolds. Alkaline phosphatase activity and osteonectin expression of the osteoblasts cultured on the PLGA scaffolds remained stable over three weeks, whilst expression of collagen type ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2397844 Tue, 05 May 2009 04:00:00 +0100 2397844 http://www.medworm.com/index.php?rid=2397843&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F6%2F519%3Frss%3D1 We investigated synthetic conditions for the fabrication of bioactive hybrid gels from monomers of 2-hydroxyethylmethacrylate (HEMA) and 3-methacryloxypropyltrimethoxysilane (MPS) in combination with CaCl2, at a starting molar ratio of HEMA: MPS : CaCl2 of 9 : 1 : 1. Hydroxyapatite formation, essential to show bone bonding, was observed on the HEMA— MPS—CaCl 2 hybrid gels with the added catalysts NH3 or HCl with a molar ratio to MPS of 0.1, but not on the hybrid gel with HCl at a molar ratio to MPS of 1. The mechanical properties of the gels were dependent on the catalysts, which may affect the microstructures that develop during sol—gel processing. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2397843 Tue, 05 May 2009 04:00:00 +0100 2397843 http://www.medworm.com/index.php?rid=2397842&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F6%2F497%3Frss%3D1 This study reports the effects of treatment with various concentrations of organic solvents for varying time points on matrices of fibroin, a silk protein isolated from the mulberry silkworm, Bombyx mori, which in native form has been extensively used in tissue engineering. Treatment of pure fibroin as well as polyethylene glycol- blended films with 90% organic solvent for 60 min induces optimal surface hydrophobicity and maximum conversion of the secondary structure from random coil to β sheet. Long-term cell viability studies reveal that methanol and isopropanol-treated pure and blended films support cell adhesion, proliferation, and viability. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2397842 Tue, 05 May 2009 04:00:00 +0100 2397842 http://www.medworm.com/index.php?rid=2397841&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F6%2F481%3Frss%3D1 This study aims to construct a hybrid biomaterial by seeding osteoblastic cells into a CaP/PLGA scaffold by a centrifugal force. Constructs are evaluated with respect to potential application in bone tissue engineering. Cells adher, spread, and form a layer of tissue lining the scaffold and are capable of migrating, proliferating, and producing mineralized matrix. We have demonstrated that the centrifugal force is highly efficient for constructing a hybrid biomaterial, which acts similarly to bone explants in a cell culture environment. In this way, these constructs could mimic an autogenous bone graft in clinical circumstances. Such a strategy may be useful for bone tissue engineering. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2397841 Tue, 05 May 2009 04:00:00 +0100 2397841 http://www.medworm.com/index.php?rid=2220909&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Freprint%2F23%2F5%2F473-b%3Frss%3D1 (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2220909 Fri, 27 Feb 2009 05:00:00 +0100 2220909 http://www.medworm.com/index.php?rid=2220908&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Freprint%2F23%2F5%2F473-a%3Frss%3D1 (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2220908 Fri, 27 Feb 2009 05:00:00 +0100 2220908 http://www.medworm.com/index.php?rid=2220907&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Freprint%2F23%2F5%2F473%3Frss%3D1 (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2220907 Fri, 27 Feb 2009 05:00:00 +0100 2220907 http://www.medworm.com/index.php?rid=2220906&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F5%2F453%3Frss%3D1 We assess the effects of chemical processing, ethylene oxide sterilization, and threading on bone surface and mechanical properties of bovine undecalcified bone screws. In addition, we evaluate the possibility of manufacturing bone screws with predefined dimensions. Scanning electronic microscopic images show that chemical processing and ethylene oxide treatment causes collagen fiber amalgamation on the bone surface. Processed screws hold higher ultimate loads under bending and torsion than the in natura bone group, with no change in pull-out strength between groups. Threading significantly reduces deformation and bone strength under torsion. Metrological data demonstrate the possibility of manufacturing bone screws with standardized dimensions. (Source: Journal of Biomaterials Application... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2220906 Fri, 27 Feb 2009 05:00:00 +0100 2220906 http://www.medworm.com/index.php?rid=2220905&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F5%2F435%3Frss%3D1 In this study, we characterize chitosan derivatives formed using a combination of carboxymethylation and a bimodal molecular weight distribution. Specifically, chitosan is carboxymethylated to a theoretical extent of ~30% as described in our previous work, in which carboxyl groups possessing negative charges are created at a physiological pH. Carboxymethyl chitosan is used to form films and constructs by varying the ratio of high to low molecular weight (MW) while maintaining the mechanical properties of the polymer. The rate of degradation is found to be dependent upon both the carboxymethylation and the ratio of high to low MW polymer, as determined by dry weight loss in lysozyme solution in PBS. Subsequently, biocompatibility is examined to determine the effects of these modifications u... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2220905 Fri, 27 Feb 2009 05:00:00 +0100 2220905 http://www.medworm.com/index.php?rid=2220904&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F5%2F407%3Frss%3D1 In an effort to enhance physical properties of biopolymers (high-density polyethylene, HDPE) in terms of elastic modulus and hardness, various ceramic fillers, like alumina (Al2O3) and hydroxyapatite (HAp) are added, and therefore it is essential to assess the friction and wear resistance properties of HDPE biocomposites. In this perspective, HDPE composites with varying ceramic filler content (upto 40vol%) were fabricated under the optimal compression molding conditions and their friction and wear properties were evaluated against Al2O3 at fretting contacts. All the experiments were conducted at a load of 10 N for duration of 100,000 cycles in both dry as well as simulated body fluid (SBF). Such planned set of experiments has been designed to address three important issues: (a) whether th... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2220904 Fri, 27 Feb 2009 05:00:00 +0100 2220904 http://www.medworm.com/index.php?rid=2220903&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F5%2F385%3Frss%3D1 Bioresorbable drug-eluting films can be used in many biomedical applications. Examples for such applications include biodegradable medical support devices which combine mechanical support with drug release and antibiotic-eluting film coatings for prevention of bacterial infections associated with orthopedic implants or during gingival healing. In the current study, bioresorbable drug-loaded polymer films are prepared by solution processing. Two film structures are studied: A polymer film with large drug crystals located on its surface (A-type) and a polymer film with small drug particles and crystals distributed within the bulk (B-type). The basic mode of drug dispersion/location in the film (A or B-type) is found to be determined mainly by the process of film formation and depends mainly ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2220903 Fri, 27 Feb 2009 05:00:00 +0100 2220903 http://www.medworm.com/index.php?rid=2083285&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F4%2F367%3Frss%3D1 Poly(styrene-block-isobutylene-block-styrene) (`SIBS') is selected for a novel trileaflet heart valve due to its high resistance to oxidation, hydrolysis, and enzyme attack. SIBS is modified using six different phospholipids and its mechanical properties characterized by tensile stress, peel strength, shear strength, contact angle, and surface energy, and then for hemocompatibility by studying the adhesion of fluorescently labeled platelets in a parallel plate chamber under physiological flow conditions. Phospholipid modification decreases SIBS tensile stress (at 45% strain) by 30% and reduces platelet adhesion by a factor of 10, thereby improving its hemocompatibility and its potential use as a synthetic heart valve. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2083285 Tue, 06 Jan 2009 05:00:00 +0100 2083285 http://www.medworm.com/index.php?rid=2083284&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F4%2F347%3Frss%3D1 Chondrocytes have been demonstrated to be sensitive to mechanical stimuli, such as compression, tension, shear force, and hydrostatic pressure. The responses of chondrocytes to mechanical compression have been often studied in vitro with cartilage and chondrocyte/hydrogel systems. The aim of this study was to investigate the effects of dynamic compression on gene expression of rabbit chondrocytes which were seeded in elastic polyurethane scaffolds with or without collagen gel encapsulation. Dynamic compression of 20% or 30% strain with 0.1 Hz frequency was applied to the cell-seeded scaffolds for 4, 8, 12, or 24 h, and then the expression of the three genes related to chondrogenic phenotype, type I and II collagens and aggrecan, was analyzed by RT-PCR. We also investigated the gene express... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2083284 Tue, 06 Jan 2009 05:00:00 +0100 2083284 http://www.medworm.com/index.php?rid=2083283&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F4%2F331%3Frss%3D1 The purpose of this study is to develop a novel recombinant human bone morphogenetic protein-2 (rhBMP-2) sustained release scaffold for dental implant osseointegration, and to evaluate the effect of this scaffold on promoting bone formation. RhBMP-2 was encapsulated in the poly-D,L-lactide-co-glycolide (PLGA) biodegradable microspheres, which were subsequently dispersed in a chitosan/collagen composite scaffold. This rhBMP-2 microspheres-loaded scaffold (S-MB) was compared with a chitosan/collagen scaffold without microspheres that directly encapsulated rhBMP-2 (S-B) in vitro and in vivo. The microstructure of the new scaffold was examined with scanning electron microscopy. The release profile of rhBMP-2 in vitro was measured at interval periods. The effect of rhBMP-2 encapsulated scaffold... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2083283 Tue, 06 Jan 2009 05:00:00 +0100 2083283 http://www.medworm.com/index.php?rid=2083282&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F4%2F311%3Frss%3D1 The potential of guar gum as a film coating material for colon-specific delivery of 5-fluorouracil is evaluated in this study. The guar gum-based multi-unit pellet system is prepared by coating guar gum and pH-sensitive polymer Eudragit FS30D sequentially around drug-loaded non-pareil cores in a fluid-bed coater. The outer Eudragit FS coating protects the system against gastrointestinal environment and dissolves rapidly in distal small intestine, where a lumen pH of over 7 triggers the dissolution of the enteric polymer. The inner guar gum coating works as a time-controlled retardant and offers additional protection of the pellets until it is degraded by microbial enzymes at the proximal colon. In vitro results indicate that guar gum is a feasible coating material to achieve timed and enzy... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2083282 Tue, 06 Jan 2009 05:00:00 +0100 2083282 http://www.medworm.com/index.php?rid=2083281&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F4%2F293%3Frss%3D1 This study has identified a process and conditions which can be used in our stent coating research. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=2083281 Tue, 06 Jan 2009 05:00:00 +0100 2083281 http://www.medworm.com/index.php?rid=1942437&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Freprint%2F23%2F3%2F288%3Frss%3D1 (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1942437 Fri, 07 Nov 2008 05:00:00 +0100 1942437 http://www.medworm.com/index.php?rid=1942436&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F3%2F275%3Frss%3D1 In conclusion, the EDC-SC gel can be used as a scaffold to support HUVEC growth, although the integrin-mediated attachment manner differs between the two gels. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1942436 Fri, 07 Nov 2008 05:00:00 +0100 1942436 http://www.medworm.com/index.php?rid=1942435&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F3%2F263%3Frss%3D1 Water uptake and water loss have been studied in a commercial resin-modified glass-ionomer cement, Fuji II LC, under a variety of conditions. Uptake was generally non-Fickian, but affected by temperature. At room temperature, the equilibrium water uptake values varied from 2.47 to 2.78% whereas at low temperature (12°C), it varied from 0.85 to 1.18%. Cure time affected uptake values significantly. Water uptake was much lower than in conventional glass-ionomer restorative cements exposed to water vapor. Loss of water under desiccating conditions was found to be Fickian for the first 5 h loss at both 22 and 12°C. Diffusion coefficients were between 0.45 and 0.76 x 10 -7 cm2/s, with low temperature diffusion coefficients slightly greater than those at room temperature. Plotting water ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1942435 Fri, 07 Nov 2008 05:00:00 +0100 1942435 http://www.medworm.com/index.php?rid=1942434&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F3%2F247%3Frss%3D1 In this study, the effects of sodium carbonate (Na2CO3 ) solution with different concentrations (10, 15, 20, and 25 wt%) as liquid phase on the setting time and compressive strength of tricalcium silicate bone cements are investigated. The in vitro bioactivity and degradability of the resultant Ca3SiO5-Na2CO3 solution paste was also studied. The results indicate that as the concentration of Na2CO3 solution varies from 0 to 25 wt%, the initial and final setting time of the cement decrease significantly from 90 to 20 min and from 180 to 45min, respectively. After setting for 24 h, the compressive strength of Ca3SiO5-Na2CO3 solution paste reaches 5.1MPa, which is significantly higher than that of Ca 3SiO5-water cement system. The in vitro bioactivity of the cements is investigated by soaking ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1942434 Fri, 07 Nov 2008 05:00:00 +0100 1942434 http://www.medworm.com/index.php?rid=1942433&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F3%2F229%3Frss%3D1 Fluid dynamic environment and scaffold architectures have an important influence on cell growth and distribution inside the scaffold. A porous cylindrical scaffold with a central channel is seeded with the sheep mesenchymal stem cells (MSCs) in this study. Then the cell seeded scaffold is continuously perfused with -MEM medium by a peristaltic pump for 7, 14, and 28 days. Histological study shows that the cell proliferation rates are different throughout the whole scaffolds. The different cell coverage is shown in various positions of the scaffold. A computational fluid dynamics (CFD) modeling is used to simulate the flow conditions within perfused cell-seeded scaffolds to give insight into the mechanisms of these cell growth phenomena. Relating the simulation results to perfusion experime... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1942433 Fri, 07 Nov 2008 05:00:00 +0100 1942433 http://www.medworm.com/index.php?rid=1942432&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F3%2F213%3Frss%3D1 The use of polymethylmethacrylate (PMMA)-based bone cement is popular in orthopedics for the fixation of artificial joints with bone. However, it has a major problem with prostheses loosening because of coverage by fibrous tissue after long-term implantation. Recently, a bioactive bone cement has been developed that shows direct bonding to living bone through modification of PMMA resin with -methacryloxypropyltrimethoxysilane (MPS) and calcium acetate. The cement is designed to exhibit bioactivity, through incorporation of silanol groups and calcium ions. Thus, it has the potential to form a layer of bone-like hydroxyapatite, which is essential for achieving direct bonding to living bone. This type of modification allows the cement to show spontaneous hydroxyapatite formation on its surfac... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1942432 Fri, 07 Nov 2008 05:00:00 +0100 1942432 http://www.medworm.com/index.php?rid=1942431&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F3%2F197%3Frss%3D1 Various calcium phosphates are used for bone repair. Although hydroxyapatite (HA) sintered ceramics are widely used due to their osteoconductivity, its bioresorbability is so low that HA remains in the body for a long time after implantation. In contrast, tricalcium phosphate (TCP) ceramics show resorbable characters during bone regeneration, and can be completely substituted for the bone tissue after stimulation of bone formation. Therefore, much attention is paid to TCP ceramics for scaffold materials for supporting bone regeneration. This paper reviews bioresorbable properties of calcium phosphate ceramics derived from β-TCP and -TCP. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1942431 Fri, 07 Nov 2008 05:00:00 +0100 1942431 http://www.medworm.com/index.php?rid=1797246&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F2%2F169%3Frss%3D1 The in vitro effect of platelet-rich plasma (PRP) on cell loading, proliferation, and osteogenic differentiation of human mesenchymal stem cells (MSC) is assessed on distinct resorbable and synthetic calcium phosphate scaffolds. A high specific surface area scaffold composed of calcium-deficient hydroxyapatite (CDHA; 48m2/g) is compared with one made out of β-tricalcium phosphate (β-TCP; surface area <0.5 m2/g). Fivefold concentrated fresh PRP is applied to scaffolds loaded with 2 x 105 MSC (n = 5). These constructs are kept in a medium with osteogenic supplements for 3 weeks. The addition of PRP leads to a higher cell loading efficiency of MSC on CDHA (p = 0.0001), that reaches the values of β-TCP. ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1797246 Tue, 16 Sep 2008 04:00:00 +0100 1797246 http://www.medworm.com/index.php?rid=1797245&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F2%2F147%3Frss%3D1 Converting the surface of poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogel into a cell-adhesive surface has been successfully achieved through a method based on atom transfer radical polymerization (ATRP) grafting. Following activation of the surface hydroxyl groups of PHEMA by bromination, surface-initiated ATRP of mono(2-methacryloyloxyethyl) phosphate (MMEP) was conducted in a methanol—water system with Cu(I)Br as catalyst at room temperature. The conversion of PHEMA hydroxyl groups to brominated isobutyryl groups and the occurrence of grafting of PMMEP were confirmed by infrared and X-ray photoelectron spectroscopies. Cell attachment experiments were conducted by culturing human corneal limbal epithelial cells on the PMMEP-grafted PHEMA, and on unmodified PHEMA and tissue cultu... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1797245 Tue, 16 Sep 2008 04:00:00 +0100 1797245 http://www.medworm.com/index.php?rid=1797244&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F2%2F123%3Frss%3D1 The optimization, through a Design of Experiments (DoE) approach, of a microencapsulation procedure for isolated neonatal porcine islets (NPI) is described. The applied method is based on the generation of monodisperse droplets by a vibrational nozzle. An alginate/polyornithine encapsulation procedure, developed and validated in our laboratory for almost a decade, was used to embody pancreatic islets. We analyzed different experimental parameters including frequency of vibration, amplitude of vibration, polymer pumping rate, and distance between the nozzle and the gelling bath. We produced calcium—alginate gel microbeads with excellent morphological characteristics as well as a very narrow size distribution. The automatically produced microcapsules did not alter morphology, viability... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1797244 Tue, 16 Sep 2008 04:00:00 +0100 1797244 http://www.medworm.com/index.php?rid=1797243&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F2%2F101%3Frss%3D1 In this study we have examined whether collagen—chitosan nerve guides promotes nerve repair compared to chitosan nerve guides using histological analysis. Results indicates that the enclosed structure of the nerve guide both promotes and supports axonal sprouting. Collagen—chitosan guides improved axonal maturation measured by a significant increase in axon diameter and axon area. These findings indicate that the collagen—chitosan nerve guides can be applied to repair severed peripheral nerve ends. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1797243 Tue, 16 Sep 2008 04:00:00 +0100 1797243 http://www.medworm.com/index.php?rid=1559538&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F1%2F85%3Frss%3D1 This study investigates the in-depth polymerization of dual-cured resin cement (Enforce; Dentsply, shades A2, B1, and opaque). Cylindrical specimens are obtained by photo-activation through ceramic. Control samples are light-cured without using ceramic. Samples are tested after 15 min or 24 h. Knoop hardness readings are made at 100, 300, 500, and 700 µm depth. Hardness is generally dependent on the mode of activation and post-cure time. Shades A2 and B1 show higher hardness values than opaque resin. Hardness at 100 µm is higher than at 700 µm. A linear relationship between hardness and depth is observed. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1559538 Tue, 01 Jul 2008 04:00:00 +0100 1559538 http://www.medworm.com/index.php?rid=1559537&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F1%2F73%3Frss%3D1 Various materials including glass and polymers have been widely used for stem cell culture due to their biocompatibility. However, the roles of these materials are fundamentally limited because they cannot realize or imitate the complex biological functions of living tissues, except in very simple cases. Here, the development of a bio-derived material suitable for stem cell culture and improvement of differentiation efficiency to specific cell lineages with no stimulating agents by using a chorion obtained from a fertilized zebrafish egg through the removal of the yolk and embryonic cell mass from the egg is reported. Mouse P19 EC stem cells introduced into the empty chorion form a uniform embryoid body (EB) without addition of any inducing agent. It is demonstrated that the zebrafish chor... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1559537 Tue, 01 Jul 2008 04:00:00 +0100 1559537 http://www.medworm.com/index.php?rid=1559536&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F1%2F51%3Frss%3D1 The aim of this work is to examine the corrosion properties, chemical composition, and material—implant interaction after different periods of implantation of plates used to correct funnel chest. The implants are made of 316L stainless steel. Examinations are carried out on three implants: new (nonimplanted) and two implanted for 29 and 35 months. The corrosion study reveals that in the potential range that could occur in the physiological condition the new bar has the lowest current density and the highest corrosion potential. This indicates that the new plate has the highest corrosion resistance and the corrosion resistance could be reduced during implantation by the instruments used during the operation. XPS analysis reveals changes in the surface chemistry. The longer the implant... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1559536 Tue, 01 Jul 2008 04:00:00 +0100 1559536 http://www.medworm.com/index.php?rid=1559535&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F1%2F37%3Frss%3D1 Hydroxyapatite (HA) is widely used in filling of bone defects and coating on metal parts of prosthetic implants due to its excellent biocompatibility, bioactivity, and bone-bonding properties. It has been demonstrated that micro-sized HA particles cause inflammatory reaction, especially for the needle shaped particles. However, little effort has been concentrated on the cell responses of the spherical HA nanoparticles. The aim of the present work is to chemically and physically characterize the synthesized HA nanoparticles and to investigate the in vitro cell responses. X-ray diffraction, electron microscopy, nitrogen adsorption, and Fourier transform infrared spectroscopy revealed that the particles consisted of nearly ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1559535 Tue, 01 Jul 2008 04:00:00 +0100 1559535 http://www.medworm.com/index.php?rid=1559534&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F23%2F1%2F5%3Frss%3D1 Chitosan, a natural based-polymer obtained by alkaline deacetylation of chitin, is nontoxic, biocompatible, and biodegradable. These properties make chitosan a good candidate for the development of conventional and novel drug delivery systems. Chitosan has been found to be used as a support material for gene delivery, cell culture, and tissue engineering. However, practical use of chitosan has been mainly confined to the unmodified forms. For a breakthrough in utilization, especially in the field of controlled drug delivery, graft copolymerization onto chitosan will be a key point, which will introduce desired properties and enlarge the field of the potential applications of chitosan by choosing various types of side chains. Chemical modification of chitosan is useful for the association o... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1559534 Tue, 01 Jul 2008 04:00:00 +0100 1559534 http://www.medworm.com/index.php?rid=1398790&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F6%2F559%3Frss%3D1 Bone morphogenetic protein-2 (BMP-2) is a well-known osteoinductive protein, which requires a carrier for local application. As an alternative to the previously described carriers, an in situ hardening, resorbable, and osteoconductive β-tricalcium phosphate cement (TCP) is tested. Trepanation defects in the bovine distal femoral epiphysis are filled with a composite consisting of TCP and 200 µg rhBMP-2 per cm3 TCP, autologous bone graft, pure TCP, or left empty. A radiological follow-up is performed after 7 weeks and 3 months. The sheep are euthanized and bone samples are analyzed by microradiography, histology, and histomorphometry. Microradiography and histology show similar results for pure TCP and the composite. The defects are filled with trabecular bone and newly formed bo... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1398790 Fri, 25 Apr 2008 04:00:00 +0100 1398790 http://www.medworm.com/index.php?rid=1398789&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F6%2F545%3Frss%3D1 In conclusion, HA and CMP do not seem to be able to activate platelets by themselves. However, if they had collagen grafted onto them, they could activate platelets and release growth factors. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1398789 Fri, 25 Apr 2008 04:00:00 +0100 1398789 http://www.medworm.com/index.php?rid=1398788&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F6%2F527%3Frss%3D1 Non-viral methods of gene delivery are attractive alternatives compared to virus-based gene delivery. Polyamidoamine (PAMAM) dendrimers are a new class of highly branched spherical polymers and have a unique surface of positively charged primary amine groups. They can form complex with DNA by electrostatic interaction, and deliver gene into cells. The ability of G5 PAMAM dendrimers binding and transferring DNA to cells has been investigated, and the effect of this complex to cell viability has been evaluated. G5 PAMAM dendrimers can bind DNA and transfer it to cultured cells efficiently, and have low cytotoxicity. The complex of PAMAM dendrimer—DNA can remain intact in a broad pH range, and also can prevent DNA from being degraded by restriction enzyme. Using the EGFP-C2 gene as mark... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1398788 Fri, 25 Apr 2008 04:00:00 +0100 1398788 http://www.medworm.com/index.php?rid=1398787&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F6%2F505%3Frss%3D1 Two series of glasses of general formula (2-p) SiO2·1.1Na 2O·CaO·pP2O5·xZnO (p=0.10, 0.20; x=0.0, 0.16, 0.35, and 0.78) have been analyzed for physico-chemical surface features before and after contact with simulated body fluid, morphological characteristics, and osteoblast-like cells behavior when cultured on them. The resulted good cell adhesion and growth, along with nonsignificant changes of the focal contacts, allow the authors to indicate HZ5 and HP5Z5 glasses as the ones having optimal ratio of Zn/P to maintain acceptable cell behavior, comparable to the bioactive glass (Bioglass®) used as a control; results are also rationalized by means of three-dimensional models derived by molecular dynamic simulations, with decomposition and conversion rates opti... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1398787 Fri, 25 Apr 2008 04:00:00 +0100 1398787 http://www.medworm.com/index.php?rid=1398786&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F6%2F485%3Frss%3D1 Previously, a strong and bioactive ceramic scaffold consisting of a porous zirconia body coated with apatite double layers (fluorapatite (FA) as an inner layer and hydroxyapatite (HA) as an outer layer) was successfully fabricated. In this contribution, the authors investigate the in vivo performance of the engineered bioceramic scaffolds using a rabbit calvarial defect model. In particular, the porosity and pore size of the scaffolds are varied in order to observe the geometrical effects of the scaffolds on their bone formation behaviors. The scaffolds supported on a zirconia framework can be produced with an extremely high porosity (~84—87%), while retaining excellent compressive strength (~7—8 MPa), which has been unachievable in the case of pure apatite scaffolds (~74% poro... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1398786 Fri, 25 Apr 2008 04:00:00 +0100 1398786 http://www.medworm.com/index.php?rid=1297240&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F5%2F465%3Frss%3D1 Bioactive poly-(DL-lactic acid) (PDLLA)—wollastonite composite films are successfully fabricated using surface modified wollastonite (mβ-CaSiO 3) particles through solvent casting-evaporation method. The surface modification of β-CaSiO3 particles are conducted by reaction of the ceramic particles with dodecyl alcohol. Surface morphology, tensile strength, and bioactivity of the composite films are investigated. The results show that the particle distribution and tensile strength of the composite films with modified β-CaSiO3 particles are significantly improved while the bioactivity is retained. As a result, the maximum tensile strength is enhanced 52.2% when compared with the PDLLA&mdas... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1297240 Wed, 12 Mar 2008 04:00:00 +0100 1297240 http://www.medworm.com/index.php?rid=1297239&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F5%2F449%3Frss%3D1 Newly synthesized vanadyl-poly(-glutamic acid) complex (VO--PGA) with a VO(O4) coordination mode was found to have potent antidiabetic activity in streptozotocin (STZ)-induced type 1 diabetic mice (STZ-mice), compared with that of a solution containing only vanadyl sulfate, VOSO 4. This was the first example of orally active vanadyl complex of -PGA for treating STZ-mice. To better define its efficacy, we examined here the effects of VO--PGA treatment in STZ-mice by oral administration at the dose of 10 mg V/kg body mass for a longer period time than our previous study. The improvement in diabetic states in STZ-mice compared with saline-treated nondiabetic normal Std ddY mice. It was found that the elevated blood glucose levels in STZ-mice significantly decreased after 3 days and sustained ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1297239 Wed, 12 Mar 2008 04:00:00 +0100 1297239 http://www.medworm.com/index.php?rid=1297238&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F5%2F433%3Frss%3D1 Magnetite nanocrystals have been widely used in many fields. Recently, a new magnetite nanocrystals, called magnetosome, has been found in magnetotactic bacteria. In this article, we researched on the properties of magnetosomes in detail, such as crystalline, morphology, crystal-size distributions, vitro cytotoxicity, and magnetic properties and quantified primary amino groups on the magnetosomes membrane surface by fluorescamine assay for the first time. From the results, it was clear that magnetosomes have more potential in the biomedical applications than synthetic magnetite. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1297238 Wed, 12 Mar 2008 04:00:00 +0100 1297238 http://www.medworm.com/index.php?rid=1297237&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F5%2F409%3Frss%3D1 Biodegradable polymer/bioceramic composites scaffold can overcome the limitation of conventional ceramic bone substitutes such as brittleness and difficulty in shaping. To better mimic the mineral component and the microstructure of natural bone, novel nano-hydroxyapatite (NHA)/polymer composite scaffolds with high porosity and well-controlled pore architectures as well as high exposure of the bioactive ceramics to the scaffold surface is developed for efficient bone tissue engineering. In this article, regular and highly interconnected porous poly(lactide-co-glycolide) (PLGA)/NHA scaffolds are fabricated by thermally induced phase separation technique. The effects of solvent composition, polymer concentration, coarsening temperature, and coarsening time as well as NHA content on the micro... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1297237 Wed, 12 Mar 2008 04:00:00 +0100 1297237 http://www.medworm.com/index.php?rid=1297236&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F5%2F391%3Frss%3D1 Poly(DL-lactic-co-glycolic acid) microspheres are prepared using a double-emulsion technique and are loaded with the model enzyme horseradish peroxidase (HRP). These microspheres can be used alone or as coatings for bioresorbable fibers that may be used as scaffolds for tissue regeneration applications. The present study focuses on the effect of the copolymer's composition and initial molecular weight on the microsphere structure, encapsulation efficiency, and cumulative protein release for 12 weeks. The release profiles generally exhibits an initial burst effect accompanied by slow release over an extended period of time, during which diffusion rather than degradation controlled HRP release from these structures. An increase in the initial molecular weight or in the copolymer's lactic aci... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1297236 Wed, 12 Mar 2008 04:00:00 +0100 1297236 http://www.medworm.com/index.php?rid=1102944&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F4%2F373%3Frss%3D1 The objective of this study is to evaluate the osteoconductivity and bioactivity of the Bonelike® graft in repairing surgical cystic bone defects. Bonelike® is implanted in 11 patients, aged between 24 and 53 years with a mean age of 36 years, consisting of 5 men and 6 women. According to the standard follow up protocols, radiological examinations are performed and Bonelike®/bone retrieved samples have been analyzed histologically using non-decalcified sections obtained perpendicular to bone length axis. Radiographic examination and histological results clearly demonstrate an extensive new bone formation apposed on Bonelike® granules with a significant degree of maturation. These clinical applications in maxillary bone defects indicate perfect bone bonding between new bone ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1102944 Tue, 18 Dec 2007 05:00:00 +0100 1102944 http://www.medworm.com/index.php?rid=1102943&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F4%2F353%3Frss%3D1 Chitosan (CS)-modified poly(D,L-lactide-co-glycolide) (PLGA/CS) nanoparticles with cationic surface were prepared by means of emulsion—solvent evaporation technique using polyviny alcohol and chitosan as costabilizers. The preparation conditions of the cationic nanoparticles were optimized by orthogonal factorial design, and the influences of the experiment variables such as polymer concentration, the molecular weight of chitosan, etc., on the size and zeta potential of the nanoparticles were evaluated. It was shown that the diameter of the PLGA/CS nanoparticles can be controlled in the range of 150—200 nm as determined by dynamic light scattering with the optimized conditions. The zeta potential of PLGA/CS nanoparticles increased with increasing the concentration of CS (CCS) o... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1102943 Tue, 18 Dec 2007 05:00:00 +0100 1102943 http://www.medworm.com/index.php?rid=1102942&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F4%2F337%3Frss%3D1 The sealing ability of gutta-percha/sealer root canal filling was compared to a new thermoplastic synthetic polymer-based obturation material (Resilon TM), using a microleakage model and a new sequence detection assay One Cut Event AmplificatioN (OCEANTM). Eighty-eight extracted human teeth, shaped with K-Files and the ProTaper Technique, were randomly assigned to four groups (n = 22) and obturated in the apical 5 mm. Group R were obturated with the Resilon/Epiphany technique; group GP were obturated with gutta-percha and Zinc oxide eugenoe sealer; group RCH and GPCH received calcium hydroxide intracanal medication before being obturated. Sterilized specimens were inoculated with Enterococcus faecalis and incubated in sterile medium for 47 days. DNA extracted from the specimens was amplifi... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1102942 Tue, 18 Dec 2007 05:00:00 +0100 1102942 http://www.medworm.com/index.php?rid=1102941&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F4%2F309%3Frss%3D1 Porous PEGT/PBT implants with different physico-chemical characteristics were evaluated to identify its potential as biodegradable and biofunctional soft tissue filler. Implants (50 x 10 x 5mm3) were implanted subcutaneously in mini-pigs and tissue response, tissue volume generated and its consistency were assessed quantitatively with a 52 weeks follow-up. The absence of wound edema, skin irritation, and chronic inflammation demonstrated biocompatibility of all implants evaluated. The hydrophobic implants induced the mildest foreign body response, generated highest amount of connective tissue and demonstrated a decrease in copolymer MW of 34—37% compared to 90% decrease of the hydrophilic implants. The rate and extent of copolymer fragmentation seems to be the determining factor of s... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1102941 Tue, 18 Dec 2007 05:00:00 +0100 1102941 http://www.medworm.com/index.php?rid=1102940&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F4%2F293%3Frss%3D1 Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and PHBHHx—hydroxyapatite (HAP) composite scaffolds have been prepared by phase separation and subsequent sublimation of the solvent for bone tissue engineering. Scanning electron microscopy (SEM), porosity measurement, mechanical tests, and thermogravimertric analysis (TGA) are used to analyze the physical properties of the scaffolds. The biocompatibility and osteoconductivity are assessed by examining the morphology, proliferation, and differentiation of MC3T3-E1 osteoprogenitor cells seeded on the scaffolds. The PHBHHx—HAP composite scaffolds show better mechanical properties, biocompatibility, and osteoconductivity than the PHBHHx scaffolds. The results suggest that PHBHHx—HAP composite scaffolds can be employed a... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1102940 Tue, 18 Dec 2007 05:00:00 +0100 1102940 http://www.medworm.com/index.php?rid=1030837&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F3%2F275%3Frss%3D1 Two-photon polymerization technique was applied to generate three-dimensional (3D) scaffold-like structures using the photosensitive organic—inorganic hybrid polymer ORMOCER®. The structures were studied with respect to potential applications as scaffold for tissue engineering. Cell counting and comet assay, respectively, demonstrated that doubling time and DNA strand breaks of CHO cells, GFSHR-17 granulosa cells, GM-7373 endothelial cells, and SH-SY5Y neuroblastoma cells were not affected by ORMOCER®. ORMOCER® related alteration of formation of tissue specific cell-to-cell adhesions like gap junctions was ruled out by double whole-cell patch-clamp technique. Additionally, growth of cells on the vertical surfaces of 3D structures composed of ORMOCER® is shown. (Source... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1030837 Fri, 16 Nov 2007 05:00:00 +0100 1030837 http://www.medworm.com/index.php?rid=1030836&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F3%2F255%3Frss%3D1 The influence of the properties and surface micropatterning of chitosan—collagen—gelatin (CCG) blended membranes on C3A cell's activities has been investigated. It is aimed to guide the cell growth and improve the growth rate in vitro for the application in tissue engineering. Masters with micropatterns are prepared on stainless steel plates by photolithography. The CCG membranes with surface micropatterns are then fabricated by soft lithography and dry—wet phase inversion techniques. The morphology and metabolic activity of cultured C3A cells on the membranes are recorded. When the C3A cells are seeded on the membranes with micropattern spacing of 200 µm width and 80 µm depth, they adhere and aggregate in the groove of the membranes in a few minutes. The aggr... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1030836 Fri, 16 Nov 2007 05:00:00 +0100 1030836 http://www.medworm.com/index.php?rid=1030835&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F3%2F241%3Frss%3D1 Alpha-modified minimum essential medium (MEM) has been found to cross-link a 1% gellan gum solution, resulting in the formation of a self-supporting hydrogel in 1:1 and 5:1 ratios of polysaccharide: MEM. Rheological data from temperature sweeps confirm that in addition to orders of magnitude differences in G' between 1% gellan and 1% gellan with MEM, there is also a 20°C increase in the temperature at which the onset of gelation takes place when MEM is present. Frequency sweeps confirm the formation of a true gel; mechanical spectra for mixtures of gellan and MEM clearly demonstrate G' to be independent of frequency. It is possible to immobilize cells within a three-dimensional (3D) gellan matrix that remain viable for up to 21 days in culture by adding a suspension of rat bone marrow ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1030835 Fri, 16 Nov 2007 05:00:00 +0100 1030835 http://www.medworm.com/index.php?rid=1030834&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F3%2F223%3Frss%3D1 In scaffold based bone tissue engineering, both the pore size and the mechanical properties of the scaffold are of great importance. However, an increase in pore size is generally accompanied by a decrease in mechanical properties. In order to achieve both suitable mechanical properties and porosity, a multilayer scaffold is designed to mimic the structure of cancellous bone and cortical bone. A porous nano-hydroxyapatite—chitosan composite scaffold with a multilayer structure is fabricated and encased in a smooth compact chitosan membrane layer to prevent fibrous tissue ingrowth. The exterior tube is shown to have a small pore size (15—40 µm in diameter) for the enhancement of mechanical properties, ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1030834 Fri, 16 Nov 2007 05:00:00 +0100 1030834 http://www.medworm.com/index.php?rid=1030833&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F3%2F197%3Frss%3D1 This study is planned to determine the relationship of organic constituents of saliva and the corrosion of dental alloys. The organic constituents are IgA, mucine, urea, and lysozyme which are encountered in the highest amounts in saliva and the dental materials are titanium (Ti), Co—Cr—Mo and Ni—Cr—Mo alloys, and dental amalgam, the most often used metallic components in dentistry. In particular, the interactions between the commonest salivary proteins, IgA, mucine, urea and lysozyme, and Ti, Co—Cr—Mo, Ni—Cr—Mo and dental amalgam were investigated. Each alloy was evaluated by cyclic polarization in each medium. The general anodic and cathodic behavior during forward and reverse cycles, the corrosion and passivation current densities (µ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=1030833 Fri, 16 Nov 2007 05:00:00 +0100 1030833 http://www.medworm.com/index.php?rid=906905&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F2%2F181%3Frss%3D1 Polybenzyl glutamate (PBLG) or polymethyl glutamate (PMLG) films have been aminolyzed with amino alcohol and crosslinked with aliphatic diamine at 60°C for 48 h simultaneously which led to the formation of crosslinked films of polyhydroxyalkyl glutamine (PHAG). ATR-IR indicates that for the aminolysis of PBLG with 2-amino-1-ethanol or 3-amino-1-propanol, benzyl glutamate almost completely turned to hydroxyalkyl glutamine, however for the aminolysis of PMLG with 5-amino-1-pentanol, methyl glutamate partially turned to hydroxypentanyl glutamine. The water-swelling test shows that water-swelling ratio Q of PHAG films from amino alcohol with longer carbon chain was smaller, the PHAG films crosslinked by 1,2-diamino eth... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=906905 Thu, 27 Sep 2007 04:00:00 +0100 906905 http://www.medworm.com/index.php?rid=906904&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F2%2F163%3Frss%3D1 To obtain new nonviral vectors with high gene delivery efficiency and special cell targeting ability, an attractive strategy is to link ligands to polyethylenimine (PEI). Fibroblast growth factor receptors (FGFRs) are highly expressed on a variety of human cancer cells and are potential targets for cancer gene therapy. In this study, the peptides NH2-Met-Gln-Leu-Pro-Leu-Ala-ThrGly-Gly-Gly-Cys-COOH (MC11) which have been proved to combine specially with the FGFR on cell membrane are coupled to PEI using N-Succinimidyl-3-(2-pyridyldithio) propionate (SPDP) as a linker with different molar ratios (1 : 0.3, 1 : 0.75, 1 : 1.5, and 1 : 3.0) and the new polymer PEI-MC11 is verified by a series of physicochemical methods including 1H-... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=906904 Thu, 27 Sep 2007 04:00:00 +0100 906904 http://www.medworm.com/index.php?rid=906903&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F2%2F145%3Frss%3D1 A bioabsorbable microcatheter comprising of a polyglycolideco-lactide microtube and an absorbable braid is developed for the continuous delivery of therapeutic fluids directly to a surgical site. Studies conducted with tissue staining dye and radio-opaque solution using porcine models indicate that infusion of fluids in the wound site is rapid and complete. The tissue reaction to the microtube and braid is generally characterized by minimal to mild chronic inflammation or foreign body reaction that decreases in severity as the material is absorbed. The microtube is considered to be absorbed at 56 days postimplantation while the bulk of the braid is considered to be absorbed by 70 days postimplantation. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=906903 Thu, 27 Sep 2007 04:00:00 +0100 906903 http://www.medworm.com/index.php?rid=906902&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F2%2F123%3Frss%3D1 To obtain immunocompatibility, graded zirconia—hydroxyapatite (ZrO 2-HA) composite bioceramic and simplex ZrO2-HA composite bioceramic are prepared. Peripheral blood mononuclear cells (PBMCs) harvested from healthy individuals are cultured with the two ceramic extracts to assess their effect on the transformation of lymphocytes, apoptotic ratio, CD69 expression, and expression of cytokine of TNF and IL-6, with or without phytohemoagglutinin (PHA)-stimulated cells. Ceramic extracts did not activate the resting lymphocytes, whereas the response of the PHA-stimulated cells was significantly modified. The PBMCs activated by graded ZrO2-HA composite bioceramic is noticeably smaller than that by simplex ZrO2-HA composi... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=906902 Thu, 27 Sep 2007 04:00:00 +0100 906902 http://www.medworm.com/index.php?rid=906901&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Freprint%2F22%2F2%2F101%3Frss%3D1 (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=906901 Thu, 27 Sep 2007 04:00:00 +0100 906901 http://www.medworm.com/index.php?rid=788906&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F1%2F83%3Frss%3D1 Impression materials are largely used to record the geometry of dental tissue. Hence, the assessment of their possible cytotoxicity is a necessary step in the evaluation of their biocompatibility. The present study is carried out to evaluate the cytotoxicity of a new elastomeric sterile and radiopaque impression material. Human gingival fibroblasts, cultured in vitro are exposed directly to Elite Implant in three different viscosities, heavy, medium, and light. At 3, 9, 24, 48, and 72 h, the cellular proliferation is evaluated. In parallel, human gingival fibroblasts are exposed indirectly by means of fluid extracts of Elite Implant. The cellular viability is evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=788906 Thu, 09 Aug 2007 04:00:00 +0100 788906 http://www.medworm.com/index.php?rid=788905&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F1%2F71%3Frss%3D1 The so-called bioactive ceramics have been attractive because they spontaneously bond to living bone. Organic—inorganic hybrids consisting of organic polymers and the essential constituents of the bioactive ceramics, i.e., silanol (Si—OH) group and calcium ions (Ca2+), are useful as novel bone substitutes, owing to bioactivity and high flexibility. In the present study, organic—inorganic hybrids are synthesized from chitin by modification with glycidoxypropyltrimethoxysilane (GPS) and calcium chloride (CaCl2). Their apatite-forming ability is examined in a simulated body fluid (SBF). The prepared hybrids form apatite on their surfaces in SBF within 7 days. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=788905 Thu, 09 Aug 2007 04:00:00 +0100 788905 http://www.medworm.com/index.php?rid=788904&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F1%2F55%3Frss%3D1 The seeding and/or in-growth of endothelial cells on a number of blood-contacting implants are a concern for both biomaterials and tissue engineering. While endothelialization has been viewed positively, owing to their ability to regulate both smooth muscle and blood, there is evidence which suggests that endothelial cells on a nonoptimized surface may be counterproductive. The present study describes the experimentation designed to elucidate the effect of culture substrate on intracellular superoxide (SO) levels, a marker for endothelial cell dysfunction. The adaptation of the use of dihydroethidium under physiologically relevant shearing conditions is also reported.The present study describes a standardized method for the use of dihydroethidium as a marker for intracellular oxidative str... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=788904 Thu, 09 Aug 2007 04:00:00 +0100 788904 http://www.medworm.com/index.php?rid=788903&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F1%2F33%3Frss%3D1 Novel in situ polymerizable liquid three-arm biodegradable oligomeric polyesters based upon glycolic acid (GA), L-lactic acid (LLA), and their copolymers are synthesized and characterized. Injectable and in situ curable polymer neat resins and their composites formulated with bioabsorbable beta-tricalcium phosphate are prepared at room temperature using photo- and redox-initiation systems, respectively. The cured neat resins show the initial compressive yield strength (YCS, MPa), modulus (M, MPa), ultimate compressive strength (UCS, MPa), and toughness (T, kN mm), ranging from 4.0 to 20.1, 201.5 to 730.2, 82.7 to 310.5, and 1.02 to 3.93. The cured composites show the initial YCS, M, UCS and T, ranging from 27.7 to 56.4, 1440 to 4870, 81.6 to 158.9, and 0.94 to 1.97. Increasing GA/LLA ratio... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=788903 Thu, 09 Aug 2007 04:00:00 +0100 788903 http://www.medworm.com/index.php?rid=788902&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F22%2F1%2F5%3Frss%3D1 The main goal of this study is to evaluate potential applications of two zirconia—hydroxyapatite composites, Z4H6 and Z6H4, as bone substitutes. Composite plugs were implanted into the distal femoral metaphysis and also onto the longissimus dorsi of 18 adult mixed-breed dogs in order to assess in vivo biocompatibility by immediate clinical and radiographic evaluation 30, 90, and 120 days after implantation. Radiographic examination revealed radiolucency on the defect site. However, a progressive increase in bone density was observed over time, reaching a radiopacity similar to that of bone 120 days after implantation. Histological study revealed that a thin layer of fibroblasts was observed at the implant—b... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=788902 Thu, 09 Aug 2007 04:00:00 +0100 788902 http://www.medworm.com/index.php?rid=568140&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Freprint%2F21%2F4%2F445%3Frss%3D1 (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=568140 Mon, 23 Apr 2007 04:00:00 +0100 568140 http://www.medworm.com/index.php?rid=568139&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Freprint%2F21%2F4%2F443%3Frss%3D1 (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=568139 Mon, 23 Apr 2007 04:00:00 +0100 568139 http://www.medworm.com/index.php?rid=568138&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F4%2F431%3Frss%3D1 The aim of the present study is to evaluate the effects of intraosseous implantation of silica-based bioactive glass (BG) particles on rat kidney under experimental renal failure. The animals are assigned to one of the two groups: renal failure (RF) and renal failure + bioactive glass (RF + BG). Particles of melt-derived 45S5 BG are implanted in the marrow of one tibia of each animal in the RF + BG group. The animals are killed 24 h and 14 days postimplantation. The RF + BG group exhibits a statistically significant increase in serum urea 24 h postimplantation. The tibiae of the RF + BG group are resected and embedded in methyl-methacrylate resin. Ground sections are analyzed by light microscopy and energy-dispersive X-ray (ED... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=568138 Mon, 23 Apr 2007 04:00:00 +0100 568138 http://www.medworm.com/index.php?rid=568137&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F4%2F413%3Frss%3D1 To further enhance the properties of chitosan (Cs)-gelatin (Gel) scaffolds for skin tissue engineering, hyaluronic acid (HA) is introduced to the Cs—gel complex. Porous scaffolds composed of Cs, Gel, and HA are prepared using the freeze-drying method. The scaffold has an interconnected pore structure with two different pore size layers. The water uptake ability, flexibility, and biocompatibility of the scaffold are greatly increased with the incorporation of HA. To construct an artificial skin in vitro, fibroblasts and keratinocytes are co-cultured in Cs—Gel—HA scaffolds at an air—liquid interface. After 2 weeks of co-culture, the epithelial layer becomes progressively stratiform, including cubi... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=568137 Mon, 23 Apr 2007 04:00:00 +0100 568137 http://www.medworm.com/index.php?rid=568136&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F4%2F395%3Frss%3D1 The use of absorbable orthopedic implants has increased substantially during the last decade. Currently, most of them are fabricated from poly-L-lactide (PLLA), its co-polymers, or mixtures with other constituents. In vivo, PLLA persists for years after its surgical role has ended, which is confirmed by a long-term histological study of PLLA implanted in sheep either as functional interference screws or nonfunctional rods. The first tissue reaction is the sequestration of the implant within new bone during the initial 3 months. After a nonreactive period, a second tissue reaction is associated with the early signs of structural disintegration of the PLLA at 1 year. Subsequently, as the polymer mass reduces, it is replaced by a... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=568136 Mon, 23 Apr 2007 04:00:00 +0100 568136 http://www.medworm.com/index.php?rid=568135&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F4%2F375%3Frss%3D1 This study explores how the resin composition/structure affects the physicochemical properties of copolymers and their amorphous calcium phosphate (ACP)-filled composites. A series of photo-polymerizable binary and ternary matrices are formulated utilizing 2,2-bis[ p-(2'-hydroxy-3'methacryloxypropoxy)phenyl]propane, 2,2-bis[ p-(2'-methacryloxypropoxy)phenyl]-propane (EBPADMA), or a urethane dimethacrylate as base monomers, and triethylene glycol dimethacrylate or hexamethylene dimethacrylate (HmDMA) with or without 2-hydroxyethyl methacrylate (HEMA) as diluent monomer. Unfilled copolymers and composites filled with 40% by mass zirconia-hybridized ACP are evaluated for biaxial flexure strength (BFS), degree of c... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=568135 Mon, 23 Apr 2007 04:00:00 +0100 568135 http://www.medworm.com/index.php?rid=568134&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F4%2F351%3Frss%3D1 Porous hydroxyapatite (HA) scaffolds have been intensively studied and developed for bone tissue engineering, but their mechanical properties remain to be improved. The aim of this study is to prepare HA-based composite scaffolds that have a unique macroporous structure and special struts of a polymer/ceramic interpenetrating composite and a bioactive coating. A novel combination of a polyurethane (PU) foam method and a hydrogen peroxide (H2O 2) foaming method is used to fabricate the macroporous HA scaffolds. Micropores are present in the resulting porous HA ceramics after the unusual sintering of a common calcium phosphate cement and are infiltrated with the poly(D,L-lactic-co-glycolic acid) (PLGA) polymer. The inter... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=568134 Mon, 23 Apr 2007 04:00:00 +0100 568134 http://www.medworm.com/index.php?rid=568133&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F4%2F333%3Frss%3D1 This study demonstrated the potential of HA/ chitosan scaffold as a good substrate candidate in periodontal tissue engineering (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=568133 Mon, 23 Apr 2007 04:00:00 +0100 568133 http://www.medworm.com/index.php?rid=375533&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F3%2F317%3Frss%3D1 Lost bone tissue due to osteoporosis makes dentistry very difficult. The aim of thisstudy is to reconstruct the bone tissue with composite biomaterials and to estimate the optical density and alveolar ridge height of the mandible. Research is conducted on 30 postmenopausal women aged from 46 to 62 years, with diagnosed osteoporosis and defects in alveolar bones caused by extraction of paradontopathic teeth, enucleation of cysts and periapical changes, extraction of impacted teeth,or by trauma.Biphasic calcium phosphate/poly-DL-lactide-co-glycolide (BCP/PLGA) composite is implanted into the defects of alveolar bones. Six weeks after implantation of BCP/PLGA, the alveolar bone density in the region of premolars on the ex... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=375533 Wed, 17 Jan 2007 07:00:00 +0100 375533 http://www.medworm.com/index.php?rid=375532&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F3%2F299%3Frss%3D1 The objectives of the present study are to optimize the setting time and mechanical properties of a CPC-chitosan composite by tailoring the chitosan content, and to evaluate the bioresorbability by using an in vitro dissolution model. Six chitosan mass fractions are tested: 0, 10, 15, 20, 25, and 30%. Specimens are immersed in solutions with pH ranging from 3.5 to 5 to simulate the acidic environments produced by osteoclasts in vivo. Dissolution is measured as the fraction of mass loss versus immersion time from 7d to 28d. The CPC-chitosan composite with 20% by mass chitosan has a setting time (mean±SD; n=4) of 13 1 min, significantly less than 87 7 min for CPC control without chitosan (p<0.05). The composite... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=375532 Wed, 17 Jan 2007 07:00:00 +0100 375532 http://www.medworm.com/index.php?rid=375531&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F3%2F283%3Frss%3D1 The aim of this study is to compare polyurethanes containing castor oil (soft segment) in granular form compared to cancellous bone autograft applied to a segmental bone defect. Norfolk adult female rabbits – approximately 13 months of age with a mean body weight of 4.5 kg – are used. In both radial diaphyses, 1 cm osteoperiosteal segmental defects are created. The defect in the left radius is filled with the castor-oil-based polyurethane, and the right one, filled with cancellous bone autograft, collected from the left proximal humerus. The rabbits are euthanazed at 15, 30, 60, and 120 days postsurgery (5 animals/ period), for histological analyses. By radiographic analyses, at these time points, the bone ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=375531 Wed, 17 Jan 2007 07:00:00 +0100 375531 http://www.medworm.com/index.php?rid=375530&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F3%2F265%3Frss%3D1 The authors have developed novel hyaluronic acid (HA)-collagen sponge materials (HACSMs) composed of various ratios of bird feet (BF) and pig skin (PS) collagen that are fabricated employing a combination of freezing, lyophilizing, and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) crosslinking methods. Morphology, swelling ratio, resistance to collagenase, thermal stability, tensile strength, and free amine index are determined to evaluate the physical-chemical properties of various HACSMs. Different BF: PS ratios directly vary with the physical-chemical properties of HACSMs and control their biodegradability for multiple uses. Resistance to collagenase, thermal stability, and tensile strength of HACSMs increase... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=375530 Wed, 17 Jan 2007 07:00:00 +0100 375530 http://www.medworm.com/index.php?rid=375529&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F3%2F251%3Frss%3D1 Pure bredigite (Ca7MgSi4O16) powders are synthesized by the sol-gel method. The bredigite powders are composed of polycrystalline particles with dimensions of 1-10µm. The in vitro bioactivity of the bredigite powders are examined by evaluation of hydroxyapatite (HAp) formation ability in simulated body fluid (SBF) and the effect of ionic products from bredigite dissolution on osteoblast proliferation. The results showed that bredigite induced the formation of nanocrystalline HAp after soaking in SBF for 10 days. The Ca, Si, and Mg ions from bredigite dissolution at a certain concentration range stimulates osteoblast proliferation. Our study indicates that bredigite is bioactive and might be used for preparation o... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=375529 Wed, 17 Jan 2007 07:00:00 +0100 375529 http://www.medworm.com/index.php?rid=375528&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F3%2F235%3Frss%3D1 In this study, a method for the rapid generation of a variety of bifunctional surfaces that can serve to quickly determine the selective adhesion of HEK293 cells towards different chemical functionalities has been established. Using the information about selective adhesion of HEK293 cells to bifunctional surfaces, we demonstrate the ability to construct stable, high density, and multi-welled surfaces where the mammalian cells form the walls of picoliter volume wells. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=375528 Wed, 17 Jan 2007 07:00:00 +0100 375528 http://www.medworm.com/index.php?rid=375527&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F3%2F217%3Frss%3D1 This study reports the properties of tableted microparticles based on high-amylose corn starch (HACS)–pectin blend polymers as the controlled release system for diclofenac sodium (DS). HACS–pectin blend microparticles are prepared through a modified process by the spray drying technique, which is a widely used microencapsulation technique in the pharmaceutical industry. The mean particle size of various formulations of blend microparticles is in the range of 5.8–7.3 µm. Fourier transform infrared (FTIR) spectroscopy study reveals the absence of well-defined interaction between HACS–pectin and polymers–DS. The blend microparticles thus prepared were compressed into tablets using the d... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=375527 Wed, 17 Jan 2007 07:00:00 +0100 375527 http://www.medworm.com/index.php?rid=221483&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F2%2F195%3Frss%3D1 Eudragit L100 microspheres were prepared using water-in-oil-in water (w/o/w) emulsion-solvent evaporation with polysorbate 20 as dispersing agent in the internal aqueous phase, and PVA/PVP as stabilizer in the external aqueous phase. Smaller internal and external aqueous phases provided higher drug encapsulation. The PVA-stabilized microspheres having maximum drug encapsulation (84.5 2.8%) released 7% insulin at pH 1.0 in 2 h. In phosphate buffer (pH 7.4), microspheres showed an initial burst release of 21% in 1 h with additional 35% release in the next 5 h. The smaller the volumes of internal and external aqueous phases, the lower the initial burst release. The release of drug from microspheres followed Higuchi kinetics. ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=221483 Wed, 04 Oct 2006 06:00:00 +0100 221483 http://www.medworm.com/index.php?rid=221482&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F2%2F179%3Frss%3D1 Organic-inorganic composites, prepared from bone-bonding bioactive ceramics and organic polymers, are useful for novel bone substitutes having mechanical properties analogous to natural bone. We synthesized composites from cellulose and carbonate hydroxyapatite (CHAp) in situ through mechanochemical reaction. They contained B-type CHAp analogous to bone apatite. They showed a bending strengths of 10-13 MPa and Young’s modulus of 1.5-2.2 GPa. We predicted their microstructure by comparing the measured density with the theoretical one. Cellulose was assumed to be distributed in the pore of CHAp at low cellulose content, and in grain boundaries of CHAp at high cellulose content. The composites formed calcium phosphate on th... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=221482 Wed, 04 Oct 2006 06:00:00 +0100 221482 http://www.medworm.com/index.php?rid=221481&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F2%2F167%3Frss%3D1 This study aims to conduct a histological evaluation of tissue response to a membrane obtained from demineralized bovine cortical bone, associated or not, to tetracycline (TTC). TTC treated and untreated bovine membranes were implanted in the subcutaneous tissue of rats (n = 120). The animals were killed 1, 3, 7, 15, 30, and 60 days after surgery. The tissue around the material was fixed in 10% buffered formalin for 24 h. Sections of 6 mm were stained with hematoxylin and eosin. In general, moderate to intense inflammatory response was observed in the initial periods (1 and 3 days), moderate response in the 7- and 15-day periods, and that was remarkably reduced at 30 and 60 days. Resorptions of the membranes by mononuclear ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=221481 Wed, 04 Oct 2006 06:00:00 +0100 221481 http://www.medworm.com/index.php?rid=221480&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F2%2F147%3Frss%3D1 Several methacrylate or acrylate derivatives of natural amino acids were synthesized and characterized. Based upon these derivatives, novel amino acid-constructed polyalkenoic acids were prepared and used to formulate glass-ionomer cements (GICs) with Fuji II glass filler. The effects of type of derivatives, molar ratio, molecular weight, and powder/liquid ratio were investigated. The results show that amino acid-constructed polyalkenoic acids can be formed only from amino acid methacrylate derivatives or by copolymerization of methacrylate with acrylate derivatives. Strong hydrogen bond interactions failed the polymer formation from acrylate derivatives. The cement composed of poly(methacryloyl glutamic acid-co-acrylo... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=221480 Wed, 04 Oct 2006 06:00:00 +0100 221480 http://www.medworm.com/index.php?rid=221479&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F2%2F131%3Frss%3D1 HylamerTM polyethylene is a crystalline form of polyethylene of 70% crystallinity whereas conventional polyethylene (PE) has 50% crystallinity. Crystallinity is the percentage by weight of the crystalline phase present in the whole polymer, which comprises both amorphous and crystalline phases.Clinical experience has shown that HylamerTM components used in joint prostheses, if sterilized by gamma rays in the presence of oxygen, are easily affected by wear, which leads to osteolysis. The authors have analyzed the crystallinity of polyethylene liners removed from seven patients who had received HylamerTM polyethylene implants sterilized by gamma rays in air and had suffered prosthetic loosening, using Raman spectroscopy coupled ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=221479 Wed, 04 Oct 2006 06:00:00 +0100 221479 http://www.medworm.com/index.php?rid=221478&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F2%2F119%3Frss%3D1 Akermanite (Ca2MgSi2O7) ceramics are prepared by sintering akermanite powder compacts at 1370 C for 6 h. The sintering behavior and mechanical properties of akermanite ceramics are investigated. The bioactivity of akermanite ceramics is evaluated by soaking in simulated body fluid (SBF), and hydroxyapatite (HAp) formation on the surface of akermanite ceramics after soaking is characterized by X-ray diffraction (XRD), energy dispersive spectrometry (EDS), and scanning electron microscopy (SEM). The results show that the bending strength of akermanite ceramics can reach 176 MPa, the fracture toughness is 1.83 MPa m1/2, and akermanite ceramics can induce HAp formation on their surface when soaked in SBF. Our results indic... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=221478 Wed, 04 Oct 2006 06:00:00 +0100 221478 http://www.medworm.com/index.php?rid=221477&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F2%2F109%3Frss%3D1 This study explores the possibility of growing lung cells on poly-DL-lactic acid (PDLLA) scaffolds, with a view to in future engineer pulmonary tissue for human implantation. As a first step in this process, the ability of PDLLA to maintain the growth of lung epithelium is tested using a robust cell line. Poly-DL-lactic acid has been investigated in two forms, as planar discs and as 3-D foams, and it has been demonstrated that PDLLA is not only nontoxic to pneumocytes but it also actively supports their growth. The initial findings suggest that the material is an appropriate matrix for engineering of distal lung tissue. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=221477 Wed, 04 Oct 2006 06:00:00 +0100 221477 http://www.medworm.com/index.php?rid=125991&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F1%2F93%3Frss%3D1 Self-expandable nitinol (nickel-titanium) alloys and 316L stainless steel are the most commonly used materials in the production of coronary stents. However, tantalum (Ta) has already been used to make stents for endovascular surgery and may constitute an alternative to other materials because of its better electrochemical performance, namely its higher corrosion resistance, as well as its radio-opacity. The characterization of wet polished, chemically polished, wet polished anodized, and chemically polished anodized Ta electrodes has been performed in a 0.15 M NaCl solution (simulated body fluid) using Ucorr=f(t) measurements, anodic polarizations, capacity measurements, anodic oxidations, and atomic force microscopy ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=125991 Wed, 26 Jul 2006 06:00:00 +0100 125991 http://www.medworm.com/index.php?rid=125990&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F1%2F75%3Frss%3D1 Polyvinyl alcohol—gelatin patches were developed and salicylic acid was incorporated at different stages of preparation of the patches. The patches were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry, tensile strength test, and scanning electron microscopy. The release patterns of the drug from the patches were also studied. The FTIR spectra of the blank patch indicated complete esterification of the free carboxylic groups of gelatin. The XRD studies indicated a crystalline form of the drug entrapped in the patches. Release of the drug from the patches followed Higuchian/Fickian kinetics indicating a diffusion-controlled release process. (Source... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=125990 Wed, 26 Jul 2006 06:00:00 +0100 125990 http://www.medworm.com/index.php?rid=125989&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F1%2F49%3Frss%3D1 Laser surface melting (LSM) of Ti—6Al—4V is performed in argon to improve its properties, such as microstructure, corrosion, and wear for biomedical applications. Corrosion behavior is investigated by conducting electrochemical polarization experiments in simulated body fluid (Ringer's solution) at 37 C. Wear properties are evaluated in Ringer's solution using pin-on-disc apparatus at a slow speed.Untreated Ti—6Al—4V contains +&szligbeta; phase. After laser surface melting, it transforms to acicular embedded in the prior &szligbeta; matrix. Grain growth in the range of 65—89 µm with increase in laser power from 800 to 1500 W due to increase in associated temperature is observed. The ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=125989 Wed, 26 Jul 2006 06:00:00 +0100 125989 http://www.medworm.com/index.php?rid=125988&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F1%2F33%3Frss%3D1 The aim of this study is to evaluate the influence of fibronectin immobilization on poly-L-lactic acid (PLA) films on the initial attachment of human gingival fibroblasts. Carboxylic acid groups are chemically introduced on the PLA films' surface by surface hydrolysis with 0.5 M NaOH. The contact angle of PLA surface with respect to double-distilled water decreases significantly after NaOH hydrolysis. X-ray photoelectron spectroscopy (XPS) also reveals significantly higher intensities of CC=O/CC-O after NaOH hydrolysis. Fibronectin is immobilized onto the hydrolyzed PLA surface through a condensation reaction between the carboxylic acid groups on the hydrolyzed PLA surface and the amino groups of fibronectin using wate... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=125988 Wed, 26 Jul 2006 06:00:00 +0100 125988 http://www.medworm.com/index.php?rid=125987&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F21%2F1%2F5%3Frss%3D1 Surface properties have been found to be one of the key parameters which cause degradation and of thrombogenicity in all polymers used in biomedical devices, thus signifying the importance and the necessity for quantitative and accurate characterization of the polymer surface itself as used in the construction of the device. The characterization techniques employed generally involve thermal and spectroscopic measurements, in which class the electrochemical investigations and scanning probe microscopies can also be included. Current hypotheses on the correlations that exist between surface parameters and hemocompatibility and degradation of polymers are examined herein, but concentrating on the field of clinically utili... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=125987 Wed, 26 Jul 2006 06:00:00 +0100 125987 http://www.medworm.com/index.php?rid=125992&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Freprint%2F20%2F4%2F409%3Frss%3D1 (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=125992 Thu, 30 Mar 2006 07:00:00 +0100 125992 http://www.medworm.com/index.php?rid=18506&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F4%2F377%3Frss%3D1 The aim of this work was to determine an array of mechanical, physical, and thermal properties of three pairs of commercially available acrylic bone cement brands, with the brands in each pair having the same compositions except that one contains 4.22 wt/wt% gentamicin sulfate blended with the powder by the manufacturer and the other one does not. The difference between the pairs was in the viscosity of the curing cement dough, with one pair of ‘low-viscosity’, one pair of ‘medium-viscosity’, and one pair of ‘high-viscosity’ brands being used. Thus, the brands studied cover the range of those used in anchoring some total joint replacements (TJRs). The properties determined were the s... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18506 Thu, 30 Mar 2006 07:00:00 +0100 18506 http://www.medworm.com/index.php?rid=18505&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F4%2F361%3Frss%3D1 Polysulfone (PSU) composite films filled with &szligbeta;-dicalcium silicate (-Ca2SiO4) particles are prepared by the solvent casting-evaporation method. The surface morphologies and mechanical properties of the films are determined. The bioactivity of the composite films is evaluated by soaking them in simulated body fluid (SBF) and the results show that the composites are bioactive as they induce the formation of hydroxyapatite (HAp) on the surface of the composite films. The measurement of the water contact angles suggests that the incorporation of -Ca2SiO4 particles into PSU matrix can improve the hydrophilicity of the composite. PSU composite films filled with modified -dicalcium silicate (-mCa2SiO4) particles are... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18505 Thu, 30 Mar 2006 07:00:00 +0100 18505 http://www.medworm.com/index.php?rid=18504&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F4%2F341%3Frss%3D1 Zinc-containing glass is prepared by the substitution of CaO in 58S bioactive glass with 0.5 and 4 wt% ZnO, and glass-ceramics are obtained by heat-treating the glass at 1200 C. The bending strength and in vitro bioactivity of the glass and glass-ceramics are evaluated. The results indicate that Zn promotes the crystallization of SiO2 and wollastonite in glass-ceramics, and proper crystallization can enhance the bending strength of the glass-ceramic. The in vitro results show that ZnO in glass retards the hydroxyapatite (HA) nucleation at the initial stage of simulated body fluid (SBF) soaking, but does not affect the growth of HA after long periods of soaking, and the ionic products of 58S4Z glass can stimulate the pr... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18504 Thu, 30 Mar 2006 07:00:00 +0100 18504 http://www.medworm.com/index.php?rid=18503&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F4%2F325%3Frss%3D1 This study reports the clinical use of a bioactive bone graft material, PerioGlas®, in the treatment of dental extraction sites before dental implant placement, to effect bone regeneration and to give early fixation to the implant.PerioGlas®, granules, ranging from 90 to 710 mm, are implanted after tooth extraction in three patients; after 6 months bone biopsies were performed in the site of the glass implantation and observed under Electron Scanning Microscopy.All the granules showed a biodegradation involving precipitation of calcium phosphate that worked as a scaffold for osteoblasts colonization. All cases examined showed the bioactivity of PerioGlas® granules resulting in new bone formation and biodegradation ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18503 Thu, 30 Mar 2006 07:00:00 +0100 18503 http://www.medworm.com/index.php?rid=18502&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F4%2F307%3Frss%3D1 This investigation studies porcine tissue response in tooth extraction sockets treated with root replicas made out of -tricalcium phosphate (-TCP; -Ca3(PO4)2) granules, molded and held together by thermal fusion of a thin film of polyglycolic-polylactic acid copolymer. Six left mandibular third incisors (n 1/4 6) of experimental pigs are treated with the root replicas and four contralateral incisors are used as nontreated controls (n 1/4 4). Two animals each were killed at 20, 40, and 60 weeks of observation periods. The mandibular jaw segments were prepared in toto for light microscopy by resin embedding and serial ground sectioning. Additionally, one -TCP-treated socket at 60 weeks was thoroughly investigated... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18502 Thu, 30 Mar 2006 07:00:00 +0100 18502 http://www.medworm.com/index.php?rid=18513&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F3%2F287%3Frss%3D1 Ganciclovir (GCV)-loaded poly(lactide-co-glycolide) (PLGA) microspheres, 125 ± 11 µm in diameter, are produced using the emulsification/solvent evaporation technique. The release rate of the drug is studied for 20 weeks in a phosphate-buffered solution of pH 7 at 37°C. The release of the drug shows a triphasic release pattern, i.e., an initial burst, a diffusive phase, and a second burst. The initial burst occurs within the first 2 days of immersion. After the burst, the release is by diffusion for up to 13 weeks, followed by another burst release, which signals the onset of bulk degradation of the PLGA polymer. The presence of GCV molecules decreases the hydrolytic rate of PLGA degradation. Gel permea... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18513 Mon, 19 Dec 2005 07:00:00 +0100 18513 http://www.medworm.com/index.php?rid=18512&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F3%2F267%3Frss%3D1 Collagen is a widely used raw material for biomaterial manufacture, which generally depends on chemical modifications of this fibrillar protein with cross-linking agents to improve biocompatibility and mechanical properties. However, cross-linking reduces the natural properties of collagen, such as low immune response, low toxicity as well as the ability to promote cellular growth and attachment. In this work, the modifications promoted by 1,4-dioxane solvent on the collagen present in native bovine pericardium (NBP) matrix routinely used in bioprosthesis manufacture, with or without subsequent cross-linking by glutaraldehyde, has been studied. The structural changes of NBP evaluated by scanning electron microscopy show that ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18512 Mon, 19 Dec 2005 07:00:00 +0100 18512 http://www.medworm.com/index.php?rid=18511&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F3%2F253%3Frss%3D1 Two MK5 (45CaO-45P2O5-5MgO-5K2O, in mol%) and MT13 (45CaO-37P2O5-5MgO-13TiO2, in mol%) glasses are prepared in the meta- and pyrophosphate regions and crystallized to obtain MK5B and MT13B, respectively. MK5B was obtained by controlled crystallization, and MT13B by powder sintering. As a result of these heat treatment processes, the crystalline phases precipitated in the glassy matrix are KCa(PO3)3, &szligbeta;-Ca(PO3)2, &szligbeta;-Ca2P2O7 and Ca4P6O19 phases for MK5B and CaTi4(PO4)6, TiP2O7, - and &szligbeta;-Ca2P2O7 phases for MT13B. To assess the in vivo biological behavior of these glass ceramics, a mixed granulometry in the range 250-355 µm and 355-425 µm with a ratio of ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18511 Mon, 19 Dec 2005 07:00:00 +0100 18511 http://www.medworm.com/index.php?rid=18510&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F3%2F237%3Frss%3D1 In this study, a novel composite based on HYAFF®11 polymer matrix reinforced with hydroxylapatite (HA) has been developed. Its advantage is having a similar component of the mineral phase of bone resulting in favorable osteoconductive properties. The present study has examined the compressive mechanical and surface chemical-physical properties of the novel HYAFF®11-HA composite. Preliminary biological investigations, including pH and cytotoxicity studies of the material extracts, have also been performed using an in vitro primary human osteoblast-like cell model. Moreover, protein, especially fibronectin adsorption has been investigated following incubation in culture medium and human plasma. The results show a... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18510 Mon, 19 Dec 2005 07:00:00 +0100 18510 http://www.medworm.com/index.php?rid=18509&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F3%2F221%3Frss%3D1 Five novel bifunctional oligomers containing both carboxylic acid and methacrylate groups are synthesized, characterized, and used to formulate compomers by mixing with strontium fluoroaluminosilicate glass powder at a filler level of 75% (by weight). Compressive strength (CS) of the cements and viscosity of the resin liquids are used as screening tools to find the optimal formulation. Diametral tensile (DTS) and flexural strengths (FS) are also determined. Results show that the oligomers derivatized with glycerol dimethacrylate exhibit higher CS than those with 2-hydroxyethyl methacrylate. The CS increases with increasing diluent content, filler level, and light-exposure time. During aging, the cement shows an increase of ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18509 Mon, 19 Dec 2005 07:00:00 +0100 18509 http://www.medworm.com/index.php?rid=18508&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F3%2F209%3Frss%3D1 In conclusion, the cavities that have been filled with HA and bone graft have shown higher scores than the control group during every period of the study. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18508 Mon, 19 Dec 2005 07:00:00 +0100 18508 http://www.medworm.com/index.php?rid=18507&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F3%2F195%3Frss%3D1 A hydroxyapatite (HA)-titania (TiO2) hybrid coating is developed to improve the biocompatibility of titanium (Ti) implants. The HA predeposited layer on Ti via electron beam (e-beam) evaporation is subsequently treated by micro-arc oxidation (MAO) to produce an HA-TiO2 hybrid layer on Ti. The e-beam-deposited HA layer has a thickness of 1 µm and was highly dense prior to MAO. By means of MAO treatment, a rough and porous TiO2 layer is formed beneath the HA layer with a simultaneous local dissolution of the HA layer. Due to the HA precoating, high concentrations of Ca and P are preserved on the coating surface. The osteoblast-like cells on the hybrid coating layer grow and spread favorably. The cell proliferation ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18507 Mon, 19 Dec 2005 07:00:00 +0100 18507 http://www.medworm.com/index.php?rid=18518&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F2%2F179%3Frss%3D1 The aim of this study is to examine the reparatory ability of the synthetic biomaterial hydroxyapatite-poly-L-lactide (HAp-PLLA), the replacement of alveolar ridge, and rehabilitation of bone defects caused by osteoporosis, in an experimental group of animals. The experiments are performed on syngeneic Sprague Dawley rats. Osteoporosis is induced by glucocorticoids in rats during a 12-week period. After this, the experimental group of animals is divided into five subgroups. An artificial defect is made in the alveolar bone on the left side of the mandible. In one group of animals, the defect is left to heal by itself, while in other groups, pure HAp-PLLA or one mixed with plasma is implanted. The best results are achieved ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18518 Fri, 23 Sep 2005 06:00:00 +0100 18518 http://www.medworm.com/index.php?rid=18517&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F2%2F157%3Frss%3D1 In conclusion, DD of chitosan plays an important role in their physicochemical properties and affinity with Schwann cells. The results suggest that chitosan with a DD higher than 90% is considered as a promising material for application in peripheral nerve regeneration. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18517 Fri, 23 Sep 2005 06:00:00 +0100 18517 http://www.medworm.com/index.php?rid=18516&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F2%2F137%3Frss%3D1 Composite scaffolds of polyhydroxybutyrate-polyhydroxyvalerate (PHBV) with sol-gel-derived bioactive glass (BG, 58S) are fabricated by compression molding, thermal processing, and salt particulate leaching method. Structure and mechanical properties of the scaffolds are determined. The bioactivity of the composites is evaluated by soaking the scaffolds in a simulated body fluid (SBF), and the formation of the apatite layer on the scaffolds is determined by scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS). The results show that the PHBV/BG composites are bioactive as they induce the formation of apatite on the composite scaffolds after soaking in SBF for 3 days. In addition, the measurements o... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18516 Fri, 23 Sep 2005 06:00:00 +0100 18516 http://www.medworm.com/index.php?rid=18515&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F2%2F123%3Frss%3D1 The problem of acoustic feedback in hearing aids could be solved potentially by applying a compliant hydrogel to the outer surface that would conform to the ear canal and block feedback. With this objective, several formulations of hydrogels were developed and their swelling and mechanical properties investigated. Hydrogel formulations were polymerized from hydroxyethyl methacrylate (HEMA) and N-vinyl-pyrrolidone (NVP), with various photo-initiators, crosslinkers, and swelling agents. The hydrogel that swelled most rapidly and yet remained undissolved in water had a monomer composition of 40 mol% HEMA, 60 mol% NVP, with 1 wt% polyethylene glycol dimethacrylate as a crosslinker, and 0.5 wt% 2,2-dimethoxy-2-phenyl-acetop... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18515 Fri, 23 Sep 2005 06:00:00 +0100 18515 http://www.medworm.com/index.php?rid=18514&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F2%2F103%3Frss%3D1 In conclusion, the difference in the morphology of Hylamer polyethylene wear particles in comparison with PCA might have caused a more intensive biological response, early and massive osteolysis, and therefore, early loosening. (Source: Journal of Biomaterials Applications) Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18514 Fri, 23 Sep 2005 06:00:00 +0100 18514 http://www.medworm.com/index.php?rid=18522&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F1%2F81%3Frss%3D1 This study utilized and compared a number of thermal analysis methods to characterize the thermal properties of commercial sutures with and without antimicrobial coatings of silver-doped bioactive glass (AgBG) interlocking particulates. The effect of a slurry dipping technique used to coat resorbable Vicryl® (polyglactin 910) and non-resorbable Mersilk® surgical sutures with AgBG was investigated using conventional differential scanning calorimetry (DSC), high speed calorimetry (or HYPERDSCTM), and modulated temperature DSC (MTDSC). These methods were compared in terms of their ability to resolve the thermal transitions of the types of suture materials. Differential thermal analysis (DTA) and thermogravimetric ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18522 Tue, 21 Jun 2005 06:00:00 +0100 18522 http://www.medworm.com/index.php?rid=18521&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F1%2F65%3Frss%3D1 This article reports on the use of ion chromatography (IC) to investigate extensively the release profiles of both cations and anions and characterize the relationship between composition and degradation for a ternary-based Na2O-CaO-P2O5 glass system developed as biomaterials. Studies are carried out on glasses with the formula 45P2O5-55(xCaO-Na2O) in deionized water, where x = 30, 35, and 40 mol%, using a cumulative release method, where the solution is changed at regular intervals.Degradation behavior is linear with time where the degradation rate shows an initial decrease with increasing CaO content. This rate then increases with a further addition of CaO. Cation release profiles follow similar trends to the degrada... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18521 Tue, 21 Jun 2005 06:00:00 +0100 18521 http://www.medworm.com/index.php?rid=18520&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F1%2F51%3Frss%3D1 The aim of this study is to determine the peak temperature of polymerization, the setting time and the release of residual monomers of a modified acrylic bone cement. Palacos®R, a commercial bone cement, is used as the main component. The cement is modified by adding short glass fibers and resorbable oligomer fillers, and an additional cross-linking monomer. The test specimens are classified according to the composition of the bone cement matrix (i.e., oligomer-filler, glass-fiber reinforcement, and/or cross-linking monomer). The exothermal characteristics during autopolymerization are analyzed using a transducer connected with a computer. The quantities of residual monomers were analyzed from different test groups... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18520 Tue, 21 Jun 2005 06:00:00 +0100 18520 http://www.medworm.com/index.php?rid=18519&cid=s_32013_173_f&fid=32013&url=http%3A%2F%2Fjba.sagepub.com%2Fcgi%2Fcontent%2Fabstract%2F20%2F1%2F5%3Frss%3D1 Often hard implants undergo detachment from the host tissue due to inadequate biocompatibility and poor osteointegration. Changing surface chemistry and physical topography of the surface influences biocompatibility. At present, the understanding of biocompatibility of both virgin and modified surfaces of bioimplant materials is limited and a great deal of research is being dedicated to this aspect. In view of this, the current review casts new light on research related to the surface modification of biomaterials, especially materials for prosthetic applications. A brief overview of the major surface modification techniques has been presented, followed by an in-depth discussion on laser surface modifications that have been ... Journal of Biomaterials Applications journals http://www.medworm.com/rss/comments.php?id=18519 Tue, 21 Jun 2005 06:00:00 +0100 18519