中文摘要：

采用改进的溶液浇铸／粒子沥滤工艺，将聚乳酸（PLLA）与致孔剂粒子粉碎后，制备了双层和多层孔径梯度变化的PLLA泡沫支架。扫描电镜观察表明，材料内部界面处存在一定的扩散现象，且界面处孔的连通性好，通过调整致孔剂粒子的粒径以及PLLA与致孔剂粒子的比例，可有效地调控支架的各项参数（材料大小、孔径、孔隙率）。对材料进行分形研究，表明梯度多孔支架内部无明显界面，孔径过渡平缓。

英文摘要：

Three-dimensional gradient porous foams were technique using particles of a certain size of poly（L-lactic prepared by the solvent-casting and particulate-leaching acid） and sodium chloride. SEM revealed that a highly porous three-dimensional scaffold having a well interconnected porous structure could be achieved by this process and that the pores were connected with each other around the interface. Porosity and pore size of the scaffold were controlled using different ratios of poly（L-lactic acid） to sodium chloride and particle size of the added salt particles. A fractal dimension study showed that the variation in pore size in the gradient scaffold was smooth without any obvious interface.