Chitosan/nanohydroxyapatite composite membranes via dynamic filtration for guided bone regeneration

Chitosan/hydroxyapatite (HA) composite membranes were prepared by the coprecipitation method and a subsequent dynamic filtration and freeze-drying process. The influences of the HA content of the membranes on their phase and morphology, mechanical properties, and bioactivity were investigated. FTIR analysis revealed that chitosan and HA had good miscibility over a wide range of compositions. Needle-like HA nanocrystals with low crystallinity were uniformly embedded in the chitosan matrix. As the HA content was increased, the tensile strength of the membranes exhibited a steady decrease, while the elastic modulus increased by a factor of 2 when 20% HA was added. The results of the in vitro cell culture showed that the highest alkaline phosphatase level was achieved when 30% HA was contained in the composites.