低热-高压法制备PLGA多孔支架及其体外降解研究

采用低热-高压法制备了聚(dl-丙交酯／乙交酯)75／25(PLGA75／25)组织工程多孔支架。该方法避免了使用有机溶剂，支架的孔隙率在90％以上，孔径大小分布均匀。多孔支架经过酒精处理后，支架表面产生许多微小的凹陷；用藻酸钙改性处理后，支架形态保持良好。两种处理都使支架的压缩强度有所增大，亲水性增强。虽然孔隙率高的支架降解速率稍慢，但其体外降解规律基本一致：特性粘数争力学强度衰减快，而质量损失较慢，降解6周后，支架的质量损失仅为3％左右；体外降解3周后，支架的形态保持良好，可望在细胞移植争组织修复的早期发挥支撑作用。

Scaffolds with High Porosity for Tissue Engineering Fabricated by Low Heat-High Pressure and their Degradation in Vitro

Poly(dl -lactide- co -glycolide)75/25(PLGA75/25) porous scaffolds for tissue engineering were fabricated by a novel technique of the low heat-high pressure without using organic solvents. The porosity of the scaffolds was up to 90%. Scanning electron micrograph (SEM) observations revealed that the pore size and distribution were uniform. The surface of the scaffolds treated with alcohol appeared lots of micro-caves. The morphology of the scaffolds were improved after modification by alginate calcium. The compression strength and the hydrophilicity of the scaffolds were improved after modification by the above two methods. Though the scaffolds with higher porosity degraded a little slower, the degradation behaviors in vitro of the two scaffolds with porosity of 90% and 92% respectively were mainly consistent: the intrinsic viscosity of the scaffold material and the compression strength of scaffolds decreased very fast, but the mass lost more slowly and was about 3 % mass loss after degrading for 6 weeks. The porous structure and morphology of the scaffolds held well after degrading for 3 weeks, which is expected to play an important support role in cell transplant and tissue regeneration.