β-磷酸三钙/聚左旋乳酸骨折内固定材料的体外降解性能研究

Research on in vitro degradation of β-TCP/PLLA internal fracture fixation composite material

骨折内固定材料是骨修复中不可或缺的重要材料。为了避免二次手术,可降解的骨折内固定材料越来越受到重视。本文采用溶液成膜/热压成型的方法制备了不同比例的-βTCP/PLLA骨折内固定复合材料,将不同比例的复合材料分别浸入SBF中进行体外降解,之后进行GPCI、R、吸水率分析及抗弯、抗压强度的测定,筛选出-βTCP与PLLA的最佳比例。结果表明:降解初期聚乳酸分子量下降较快,3周后下降减缓;降解后,复合材料表面形成了HCA。含20%、30%-βTCP的材料抗弯抗压下降缓慢,而40%的下降较快,初步显示30%为最适的β-磷酸三钙/聚左旋乳酸复合比例。

Internal fracture fixation material is now an indispensable material in bone repair. In order to avoid second operation, degradable one is paid more attention to recently. In this paper, solvent casting/film forming/tom pression molding technique has been used to fabricating the composited materials with different proportion of β-TCP to PLLA. The composited materials were immersed into SBF respectively. At the end of each time point, ＇some specimens were removed for test. Results showed that; at the initial stage of degradation, average molecular weight of PLLA de creased quickly and then slowly after 3 weeks. After degradation, HCA was formed on the surface of the composited material. The bending and compressive strength of the material with 20%, 30%β-TCP decreased slowly as a function of degradation time; while the 40% one fast. Therefore ifs indicated that 30% β-TCP/PLLA is the most suitable internal fracture fixation composite materials.