聚乳酸-羟基乙酸共聚物/磷酸钙骨水泥多孔复合支架的制备

利用定向冰晶-冷冻干燥法制备了具有定向孔隙结构的磷酸钙骨水泥支架材料, 将两种具有不同降解速率的聚乳酸-羟基乙酸共聚物(PLGA) 与磷酸钙骨水泥多孔支架进行多次浸润复合, 以改善支架的力学性能。结果表明: PLGA 与支架材料复合可大大提高复合支架材料的抗压强度, 经过PLGA 二次复合后, 复合支架抗压强度可达6. 37 MPa ±0. 54 MPa 。经过PLGA 复合的支架材料保持了复合前的孔隙结构, 在孔的轴向方向上具有定向排列的开口孔隙, 这些开口孔隙的存在有利于植入初期新生组织的长入。覆盖在骨水泥基体表面的PLGA 膜可以增强基体的强度并弥补基体表面的缺陷, 充填在孔隙内部的PLGA 泡沫体可以很好地承受外加载荷, 使复合支架材料具有较好的强度和韧性。 

Preparation of poly(lactic-co-glycolic acid)/calcium phosphate cement macroporous composite scaffold

A macroporous calcium phosphate cement (CPC) scaffold with oriented pore structure was prepared by the unidirectional freeze casting method. Two kinds of poly ( lactic-co-glycolic acid) ( PLGA) with different degradation rates were infiltrated into the CPC scaffold to improve the mechanical strength. The results indicate that the compressive strength of scaffolds is greatly improved via PLGA reinforcement. The compressive strength of 6. 37 MPa ±0. 54 MPa is achieved for the PLGA/CPC scaffold. The PLGA/CPC scaffolds prepared by infiltration with PLGA still possess open oriented pore structure, which would be helpful for bone ingrowth into the implant. The PLGA membrane coat on the pore walls of the CPC scaffold can strengthen the matrix and remedy the defects. PLGA sponges in the scaffold can participate in bearing the external load. These contribute to the high strength and toughness of the composite scaffold.