Calcium phosphates synthesized by reverse emulsion method for the preparation of chitosan composite membranes

Calcium deficient hydroxyapatite (CDHA) having an average particle size of 45 nm was synthesized by reverse emulsion method. It was converted to the respective biphasic calcium phosphate (BCP, 226 nm) and β-tricalcium phosphate (TCP, 450 nm) by calcination at 800 °C and 1000 °C, and the BCP consisted of 92% TCP and 8% CDHA. Subsequently, chitosan was mixed with calcium phosphates to prepare CDHA/chitosan, BCP/chitosan, and TCP/chitosan membranes. The initial moduli of the BCP/chitosan and TCP/chitosan membranes were about 1.9 times that of the pure chitosan membrane; and the elongations at break were almost 6 times. The CDHA/chitosan and BCP/chitosan could induce mineralization of apatite on the membranes by increasing 20.6 and 16.3 wt.%, respectively, after 24 days in the simulated body fluid. Moreover, the BCP/chitosan exhibited superior osteoblast cell attachment and proliferation than the other membranes. It has the potential to be used as the barrier membrane for guided bone regeneration.

► We synthesized calcium phosphates by reverse emulsion and subsequent calcination.
► BCP had 92% of β-tricalcium phosphate and 8% of calcium deficient hydroxyapatite.
► We prepared chitosan/calcium phosphate composite membranes as the barrier membrane.
► The BCP-CS has superior mechanical properties, bioactivity and bone cell affinity.
► The BCP-CS membrane can be used as the barrier membrane for guided bone regeneration.