Papers by Keyword: Biocompatibility

Abstract: In this study, the surface modification and biocompatibility of the biologic chitosan scaffold were investigated. The chitosan scaffold with excellent reticular structure was attained after being purified, emulsionized, cross-linked, molded and freeze-dried step by step by using the native materials, coming from such as lobster shell, crab shell etc.. After that, its surface modification was operated with film coating by using gelatin. Then the bone marrow mesenchymal stem cells (BMSCs) derived from New Zealand rabbits were used as the seed cells and were inoculated onto the modified biologic chitosan scaffolds at 3×105 cells/ml to investigate the biocompatibility and bone conductive efficiency of this kind of scaffold in static culture for one week. As a control, the cell suspensions with same densities were inoculated onto the chitosan scaffold without being treated. During the whole culture process, the cellular adherence and expansion were observed under inverted microscope. After culture, the biological properties of the fabricated cell-scaffold tissues were detected by scanning electron microscope (SEM) and HO/PI fluorescent double staining. The results showed that the biologic chitosan scaffold treated with gelatin or rat-tail collagen promoted a higher adhesion and proliferation of BMSCs in comparison to the untreated samples. Besides, the BMSCs within the treated scaffold were more regular and well-distributed than those in untreated one. It is concluded that this kind of surface modification can be used to change the physicochemical properties of chitosan scaffold. The improved biologic chitosan scaffold is suitable to be an ideal biomedical scaffold for tissue engineering.

Abstract: The research on ceramic scaffolds for bone tissue engineering is, nowadays, one of the newest and most attractive topics in the field of materials for biomedical applications. These scaffolds are aimed to provide supporting or even enhance the reparative capacity of body. Biphasic calcium phosphates (BCPs) and silicon doped BCP are very interesting candidates to be used as materials for scaffolds fabrication in bone tissue engineering. BCPs and silicon doped BCP consist of a mixture of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) or HA and α-tricalcium phosphate (α-TCP), respectively. For the regenerative purposes BCPs show better performance than HA because of the higher solubility of β-TCP compound, which facilitate the subsequent bone ingrowth in the implant. On the other, silicon doped BCP involve silicon that substituted into the apaptite crystal lattice for phosphorous with the subsequent charge imbalance. HA/α-TCP based bioceramics exhibits an important improvement of the bioactive behaviour with respect to non-substituted apatites. This work reviews the procedures to synthesise and fabricate scaffolds based on HA/β-TCP and silicon stabilised HA/α-TCP. Special attraction has been paid in the different synthesis methods and to the shaping of final scaffolds. By knowing the scaffold features at the crystallinity and macrostuctural level, the biocompatibility and clinical performance can be better understood, which will be also considered in this review.

Abstract: Based on a high power CO2 laser beam passing by pyramid polygon mirror, the bioceramic coatings of gradient composition were fabricated on titanium alloy substrate (Ti-6Al-4V). The relations among laser processing parameters, microstructure and biocompatibility of the gradient bioceramic coatings were investigated. The results indicated that the contents of rare earth oxide additions had an immediate effect on the formation of bioactive phases. The gradient bioceramic coatings showed favorable biocompatibility in vivo after they were implanted into canine femur for 45, 90, and 180 days, respectively. The bioceramic coatings of Ca/P=1.4 and 0.6wt.% Y2O3 totally combined with new bones merely implanted for 45 days. Furthermore, the MTT (Methyl Thiazolyl Tetrazolium) colorimetry results of cell proliferation demonstrated that the cell growth distinctly increased on the gradient bioceramic coatings by laser cladding compared with the un-treated titanium alloy substrate.

Abstract: Dedicated to Minimal Invasive Surgery MIS particularly in spine for vertebroplasty, the surgeons and radiologists ask for improvement of radio opacity, to be sure of the injection site, and to prevent injection in blood vessels. MBCP Gel® is an Injectible biomaterial non self hardening, the biomaterials consists of BCP granules associated with a hydrosoluble polymer. These materials have been shown to be perfectly biocompatible and potentially resorbable and, thanks to their initial plasticity, they assume the shape of the bone defects very easily, eliminating the need to shape the material to adjust to the implantation site. MBCP gels do not have mechanical properties like the hydraulic bone cements. However bone cells are able to invade the spaces created by the disappearance of the polymer carrier. Bone ingrowth takes place all around the granules at the expense of the resorption of the BCP granules. In time, the mechanical property is increased due to the presence of the newly formed bone. This study demonstrates an improvement of MBCP gel by freeze drying and reconstitution using iodine solution or sterile water in a classical model of rabbit bone defects.

Abstract: A great number of studies have shown that diamond-like carbon (DLC) coatings could be developed for orthopaedic implants, but few articles have been published about in vivo evaluation. In this study, DLC coatings were deposited on titanium alloy (Ti-13Nb-13Zr) implants using the plasma immersion implantation and deposition (PIII-D), and the in vivo biocompatibility of DLC coatings was evaluated into both muscular tissue and femoral condyles of rats. Results indicate that DLC coatings are biocompatible in vivo, and DLC-coated implants were observed directly bonding to bone without any intervening soft tissue layer.

Abstract: Bioactive ceramics such as hydroxypatite (HA) promote and enhance biological fixation. There is still a discussion on the desired longevity of the coating. Stable coatings require an optimum between resorption rate, flexural strength and adhesive strength of the coating. Ceramic coatings containing fluorapatite (FA, Ca5(PO4)3F) and calcium zirconium phosphate (CZP, CaZr4(PO4)6) promise lower resorption rates than conventional HA coatings in the biological milieu. It is hoped that they can improve the long-term stability of implants by eliminating the detrimental resorption of coating material. For the in vivo studies plasma sprayed coatings were generated. The materials were implanted into the distal femur epiphysis of rabbits and investigated after 2, 4, 6, 12, and 24 weeks postoperatively. Histological analysis was preformed on the areas surrounding the implant. The amount of osseointegration was determined by using the automatically image analysis. The bonding strengths were compared with HA coating and uncoated titanium alloy. According to available data, there is inhibition of mineralization of bone at the interface of calcium zirconium phosphate ceramics of the described composition.

Abstract: We have successfully developed novel “chelate-setting apatite cement” using hydroxyapatite (HAp) particles surface-modified with inositol phosphate (IP6) . The HAp particles surface-modified with IP6 were mixed with water (HAp/water ratio = 1.00/0.50[w/w]) to fabricate apatite cements. We have examined the biocompatibility of the apatite cement using the culture system of MC3T3-E1 cells and the rabbit model. The cell-culture test using MC3T3-E1 cells has shown that the apatite cement has noncytotoxicity. This cement has been implanted into tibiae of rabbits. When tissue response was examined histologically up to 24 weeks, new bone formation was observed around the surface of the cement. The present work demonstrates that this apatite cement is useful as a material for artificial bone grafting.

Abstract: The aim of this study was to evaluate the biocompatibility with the proliferation of osteoblast-like cell (MC3T3-E1) on zirconia/alumina nanocomposite (NANOZR) in comparison to yttria stabilized zirconia (3Y-TZP) and titanium (Ti). Cellular proliferations after 1-, 3-, 6-, and 9-day incubation were calculated from the measurement of the MTT activities of the proliferated cell and were analyzed by two-way ANOVA. Time-dependent proliferation of MC3T3-E1 in all the sample was observed in all three materials with culture days. However, these were no significant differences in the proliferation between three kinds of material, indicating all the materials have a similar-good biocompatibility.

Abstract: The present work is focused on the stability of bioactivated CoCr alloy in biological environment (buffered saline solution (PBS), lactic acid, citric acid). The chemical and electrochemical deposition was characterized by electrochemical methods (open circuit potential, cyclic voltametry), scanning electronic microscope (SEM), x-ray diffractometer (XRD), inductively coupled plasma/mass spectrometry (ICP/MS) and citotoxicity test. The results prove a good electrochemical stability in all cases.

Abstract: The aim of this paper was to find and establish the contact: biomaterial implant (TiAlZr) - coated with biologically active molecules; and the correlation between surface characteristics and their efficiency.