Biodegradation of carbonate apatite/collagen composite membrane and its controlled release of carbonate apatite

The aim of this study was to investigate the biodegradation of carbonate apatite (CO₃Ap)/collagen composite membrane as a new guided tissue regeneration membrane in vivo and to estimate its controlled release of CO₃Ap in vitro. To control the biodegradation of the guided tissue regeneration membrane and to promote hard tissue regeneration in the periodontal region, we added CO₃Ap into the collagen membrane. To investigate the biodegradation of CO₃Ap/collagen composite membranes, the prepared membranes (CO₃Ap:0, 10 wt %) were cut into 5 × 5 × 0.1 mm and subcutaneously implanted into the backside of male rats under general anesthesia. The explanted membranes were investigated histologically. To estimate their controlled release of CO₃Ap in vitro, the membranes (CO₃Ap 0-10 wt %, 5 × 5 × 0.1 mm) were immersed into collagenase solution and compulsorily dissolved for 48 h. Histological results suggested that the membrane had a good biocompatibility and the biodegradable period was shortened with the presence of CO₃Ap. In the solubility experiments of the membrane, eluted Ca concentrations gradually increased with total dependence on the dissolution of the collagen membrane. Our study demonstrated that the biodegradation time can be controlled by CO₃Ap contents in the membrane and CO₃Ap could be released from the membrane with the biodegradation period.