Department of Materials Science and Metallurgy, Cambridge Centre for Medical Materials, University of Cambridge, Pembroke Street, Cambridge, CB2 3QZ, United Kingdom.
Biomacromolecules. 2009 Jul 13;10(7):1976-85. doi: 10.1021/bm900397d. Epub 2009 Jun 17.
Co-continuous composites consisting of a porous calcium phosphate matrix (hydroxyapatite, HA, or β-tricalcium phosphate, TCP) filled with poly(D,L-lactide) (PDLLA) were produced with two different methods: in situ polymerization of D,L-lactide monomer inside the matrix, or infiltration of the matrix with molten polymer. The influence of the calcium phosphate matrix as well as the manufacturing method on the degradation were investigated with accelerated in vitro studies at 42 °C in pH 7.4 phosphate-buffered saline (PBS), with some controls at 37 °C. The results show that samples produced with the infiltration method had higher initial molecular weights leading to a later onset of mass loss. Heterogenous polymer degradation was still present in the composites, as indicated by molecular weight distributions and glass transition temperature measurements. The calcium phosphate matrix delayed degradation, with evidence from X-ray microtomography suggesting that the polymer degrades more slowly in proximity to the matrix.
由多孔磷酸钙基质（羟基磷灰石，HA，或β-磷酸三钙，TCP）填充聚（D，L-丙交酯）（PDLLA）组成的共连续复合材料是通过两种不同的方法生产的：在基质内原位聚合 D，L-丙交酯单体，或用熔融聚合物渗透基质。通过在 42°C 的 pH 7.4 磷酸盐缓冲盐水（PBS）中进行加速体外研究，以及在 37°C 下进行一些对照研究，考察了磷酸钙基质以及制造方法对降解的影响。结果表明，采用渗透法制备的样品具有较高的初始分子量，导致质量损失的起始时间较晚。如分子量分布和玻璃化转变温度测量所示，复合材料中仍存在不均匀的聚合物降解。磷酸钙基质延迟了降解，X 射线微断层扫描的证据表明，聚合物在靠近基质时降解速度较慢。
