中文摘要：

以丙交酯开环聚合原位接枝改性的纳米生物玻璃（PLLA-g-BG）与聚丙交酯．乙交酯（PLGA）复合材料为研究对象，采用TGA，ESEM和EDX分析其接枝率，粒子分散性和表面元素分布，通过将兔成骨细胞种植于材料膜表面进行体外培养，采用荧光染色法、NIH Image J图像分析软件、MTT法和流式细胞术等手段检测细胞在材料表面的平均黏附数量、扩展面积比、增殖能力和细胞周期的变化，综合评价新型改性纳米复合材料的生物相容性和生物活性．结果表明，聚乳酸表面接枝改性可明显改善纳米生物玻璃粒子的团聚；PLGA中掺入一定比例的改性PLLA—g—BG可明显促进兔成骨细胞的黏附、扩展与增殖；改性纳米生物玻璃的应用可提高生物可降解聚酯材料的生物相容性和生物活性．

英文摘要：

SiO2-CaO-P2O5 gel bioglass （BG） nanoparticles with the diameter of 40 nm were synthesized by sol-gel approach. The surface of BG nanoparticles was grafted through the ring-open polymerization of the L-lactide to yield poly （L-lactide） （PLLA） grafted gel particle （PLLA-g-BG）. The PLLA-g-BG was further blended with poly （lactide-co-glycolide） （PLGA） to prepare the nanocomposites of PLLA-g-BG/PLGA with the various blend ratios of two phases. PLLA-g-BG accounted 10%, 20% and 40% in the composite, respectively. TGA, ESEM and EDX were used to analyze the graft ratio of PLLA-g-BG, the dispersion of nano-particles and the surface elements of the composites respectively. The rabbit osteoblasts were seeded and cultured on the p thin films of composites in vitro. The cell adhesion, spreading and growth of osteoblasts were analyzed with FITC staining, NIH Image J software and MTT assay. The change of cell cycle was monitored by flow cytometry（FCM）. The results demonstrated that the surface modification of BG with PLLA could significantly improve the dispersing of the particles in the matrix of PLGA. The nanocomposite with 20% PLLA-g-BG exhibited superior surface properties, including roughness and plenty of silicon, calcium and phosper, to enhance the adhesion, spreading and proliferation of osteoblasts. Our results indicate that the application of PLLA-g- BG with a certain blend ratio can improve the bioactivity and biocompatibility of biodegradable polyester.