Synthesis of a bioactive and degradable 70Poly(50Lactic-co-50Glycoric acid)/30(60SiO2-40CaQ) composite with dual pore structure

The bioactive and degradable 70poly(50lactic-co-50glycoric acid)/30(60SiO₂-40CaO) composite, which had a dual pore structure, was synthesized by a gas expansion method. The bioactive 60SiO₂-40CaO powders were prepared through a sol-gel method from tetraethyl orthosilicate and calcium nitrate tetrahydrate under nitric acidic condition followed by the heat treatment at 900°C for 1 h. The 70poly(50lactic-co-50glycoric acid)/30(60SiO₂-40CaO) composite was then synthesized by a solvent casting method using 1,1,3,3-hexafluoro-2-propanol as a solvent. The disk-shaped 70poly(50lactic-co-50glycoric acid)/30(60SiO₂-40CaO) composite was loaded into the custom-made high-pressure gas chamber and then carbon dioxide gas was introduced until achieving a final pressure of 20 MPa. After 1 day of loading, the carbon dioxide gas was released rapidly. The samples were observed by FE-SEM, the phase was evaluated by X-ray diffractometer, and its bioactivity was assessed in simulated body fluid. As a result, double pore structure was developed in the poly(50lactic-co-50glycoric acid) matrix after releasing the carbon dioxide gas and 60SiO₂-40CaO particles were observed to place randomly among the poly(50lactic-co-50glycoric acid) matrix. After soaking in simulated body fluid for 1 week, flake-like low crystalline hydroxyl carbonate apatite was formed on the surface of the composite. The practical implication of the results is that it has promising potential for use as a scaffold material for bone tissue engineering due to its bioactivity and degradability.