低热高压法制作PLGA支架的三维结构研究

Analysis of three-dimensional microstructure of poly (lactide-co-glycolide) scaffolds made by mild heating under high pressure

目的制作不含有机溶剂、三维结构良好的聚丙交酯-乙交酯共聚物（PLGA）支架,使之符合组织工程骨修复的需要,探讨一种新型聚合物支架制作方法。方法将聚合物与氯化钠粉碎后,采用低热高压法制作PLGA泡沫结构支架,经密度法、氯化钠法测定其空隙率、开孔率;扫描电镜观察表面和内部结构、测定孔径。结果利用此种方法制作的PLGA支架,空隙率达到90.0％和92.5％、孔径在200-250μm之间、开孔率为98.0％以上（P<0.01）,平均氯化钠沥净时间为12～13h。结论使用低热高压法制作的组织工程支架,三维结构稳定,各项参数可控制;根据模具的大小可以制作不同体积的支架;依据盐的颗粒粒度与数量控制支架的孔径和空隙率,在制作过程中不使用有机溶剂,减少了有机溶剂残留可能引起的对细胞的毒性。使用这种方法要对聚合物与氯化钠颗粒进行充分混合。

Objective To develop a poly(lactide-co-glycolide)(PLGA) copolymer scaffold with good three-dimensional mi-crostructure and free of organic solvent, which can be used in bone repairing for tissue engineering, and to explore a novel method for developing polymeric scaffolds. Methods The polymer and sodium chloride were ground to powder and mixed in 2 different proportions as the materials for preparing the scaffolds by mild heating under high pressure. The porosity and the ratio of open pores in the product were analyzed in light of its density and by sodium chloride approaches, with the pore size, surface and internal structures examined under scanning electron microscope (SEM). Results The PLGA scaffolds made by this method had porosity of 90% and 92.5% respectively, their pore size ranging from 200 to 250 jun with the ratio of open pores exceeding 98% (f<0.01). The average sodium chloride leaching time was 12 to 13 h. Conclusions The scaffolds made in this way possess stable three-dimensional microstructure with controllable parameters and without cytotoxic effects caused by organic solvent.