TISSUE ENGINEERING AND REGENERATIVE MEDICINE, vol.11, no.5, pp.341-349, 2014 (SCI-Expanded)
Biomaterials are used in the field of bone and tissue engineering, orthopaedics and dentistry. Dental biomaterials including commercially available biodegradable materials act as physical barriers to help quicker healing while stimulating the regeneration of periodontal tissues, which is defined as Guided Tissue Regeneration (GTR). Amongst natural and synthetic biomaterials, collagen and aliphatic polyesters, such as polylactic acid (PLA) and poly (lactic-co-glycolic) acid (PLGA) are the most frequently used biomaterials for regenerative therapies due to their excellent biocompatibility and biodegradability. Due to their resorption in the body and interaction with biological systems, the GTR membranes must be sterile and pyrogen free. The sterility and apyrogenicity of the GTR membranes before human use is a regulatory requirement, however the sterilization of biomaterials is challenging due to the physicochemical changes and toxic residues with the commonly used sterilization techniques. The purpose of the present study was to evaluate the effect of gamma radiation and ethylene oxide sterilization on dental biomaterials with analytical, microbiological and histological examinations. PLGA-based GTR dental biomaterial is selected as the most gamma stable membrane according to the FTIR, DSC, TGA, and SEM results. This dental membrane was sterilized with ethylene oxide (EtO) and the effect of sterilization method on PLGA-based membrane was also investigated. Animal experiments were carried out to evaluate the regenerative properties and inflammatory responses of gamma and EtO sterilized PLGA-based GTR membrane after implantation. Histological examinations showed that resorption and bone formation of gamma sterilized PLGA-based GTR membrane was completed in 12 weeks without any inflammatory response; while only 60.095 +/- 2.019% of new bone formation was observed with EtO sterilized one. Gamma sterilized PLGA membrane had significantly faster (P < 0.05) resorption and bone formation in comparison with EtO sterilization. In conclusion, the PLGA-based biomaterials could be sterilized safely and time- and cost-effectively with validated radiation doses for the tissue engineering applications.