Three-layered membranes of collagen/hydroxyapatite and chitosan for guided bone regeneration.

The purpose of this study was to design a novel hybrid membrane with optimized properties for guided bone regeneration (GBR). Both the top and bottom layers of the sandwich-structured membrane were composed of collagen containing 20 wt% hydroxyapatite (HA), while the middle layer was made of chitosan. The above three layers were formulated into an integral membrane from their respective slurries through a layer-by-layer filtration process. The phase and composition of the membrane were confirmed by FT-IR and XRD analyses. The observation of its morphology by SEM showed that the membrane had a porous structure and structural integrity. The chitosan layer ensured the high tensile strength and elastic modulus of the membrane, while the presence of the collagen/HA composite layers endowed it with good flexibility and bioactivity. These results suggest that the integrated membrane prepared in this study would have the potential for use as a GBR material. (c) 2008 Wiley Periodicals, Inc.