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Trends in
p 17-20 BIOCOMPATIBILITY AND BIOSTABILITY OF IMPLANTED POLYURETHANE Abstract not available. p 21-23 HYDROXYAPATITE FILLED ETHYLENE VINYL ACETATE COPOLYMER
COMPOSITES FOR BONE SUBSTITUTE APPLICATIONS p 24-26 GRAFTED POLYURETHANE MEMBRANES FOR ISLET CELL
IMMUNOISOLATION:
BIOCOMPATIBILITY STUDIES Radiation grafting of monomers onto suitable trunk polymers is a useful technique for the development of biocompatible materials. Polyurethane membranes were synthesized and they were surface modified by various monomers such as hydroxyethylmethacrylate (HEMA), N-vinyl pyrrolidone (NVP) and ethylhexylacrylate (EHA) using γ-irradiation technique. These surface modified membranes were characterized using various physicochemical techniques. The biocompatibility studies of these membranes were done using VERO cells (fibroblast cells) and islet cells. The results indicate that the grafted membranes had better biocompatibility properties than the ungrafted membranes. Since the viability of islet cells on the grafted membranes were greater than the ungrafted membranes, these grafted membranes with PU-g-EHA, in particular can be proposed as ideal candidate materials for islet cell immunoisolation purposes. p 27-29 BIOCOMPATIBILITY EVALUATION OF BIPHASIC CALCIUM PHOSPHATE
CERAMICS: AN IN VIVO STUDY Biphasic calcium phosphate (BCP) ceramics consisting of hydroxyapatite (HA) and tricalcium phosphate (TCP) has been used as bone substitute material during the last decade. Varying the HA/TCP ratio can control the bioactivity and the biodegradability of BCP. Recently, many studies have demonstrated that BCP with different ratios of HA/TCP is more efficient in repairing bone defects than pure HA and pure TCP. In this paper, we present the in vivo model study of biphasic calcium phosphate ceramic prepared by microwave irradiation. The material in the form of powder was implanted in the femoral defect of dogs and the results were analyzed after 30, 60 and 90 days post-operatively. Various biochemical, radiological and histopathological changes were recorded. The radiographs showed perfect healing, uniform density of bone indicating the filling of the defective site after a period of 90 days. Serum alkaline phosphate activity levels are estimated post operatively at different intervals. The animals were euthanised and the specimens were collected for histopathological studies. The photomicrograph shows osteogenic activity and complete filling of the defect with new bone formation after a period of 90 days. p 30-36 BIO-COMPOSITES: A REVIEW OF LITERATURE The restoration of bone defects by the regeneration of natural bone is an important goal in periodontology and implantology. Many implant materials made of metals and alloys, polymers and ceramics have been tried in the past thirty years with simultaneous reported failures. The search for an alternative had stressed on the bio-composites. The possibility of combining the advantages of different materials have attracted material scientists to pay much attention on bio-composites. In this paper, we have reviewed some of the bio-composites such as ceramics/ceramics, ceramics/polymers, ceramics/metals and their applications in the replacement of bone tissues. p 37-38 POROUS HYDROXYAPATITE NANOPARTICLES FOR
INTESTINAL DELIVERY OF INSULIN Abstract not available. p 39-41 THE AMERICAN INSTITUTE FOR MEDICAL AND BIOLOGICAL ENGINEERING Abstract not available. |
