PLGA的不同组成对支架材料性能的影响研究

研究PLGA的不同组成对支架材料的力学性能、降解性能和生物学性能的影响。采用溶液浇注/颗粒沥取法制备出不同组成的PLGA多孔支架，对支架的力学性能和降解速率进行考察，同时将人真皮成纤维细胞接种于不同组成的PLGA支架材料上，培养不同时间后，检测细胞的粘附率和增殖率，以及细胞产生的总胶原含量，并通过扫描电镜观察支架上的细胞形态。结果显示，随PLA比例的增加，支架的力学强度增加，降解速率降低，但都不是线性变化。70:30比例的支架，拉伸强度最高，而70:30和80:20两种比例的支架，其降解速率没有显著性差异。PLGA不同组成的支架，均具有良好的细胞相容性，成纤维细胞粘附率和增殖率在三种比例的支架上没有显著性差异，细胞在支架表面生长良好，分泌大量的细胞外基质，细胞基本铺满整个支架。本文研究发现，PLGA的组成对支架力学性能、降解性能和生物学性能有细小但显著的影响，这将对组织构建选用PLGA支架材料提供有益的帮助。

Study on Influence of Copolymer Compositions of PLGA on Properties of Scaffolds

To investigate the influence of initial copolymer compositions of PLGA on mechanical property, degradation behavior and biological properties of the scaffolds. Porous PLGA scaffolds with different initial copolymer compositions were prepared by solvent casting/particulate leaching method. Biomechanical properties were measured using testing machine and degradation rate was detected by soaking the scaffolds in phosphate buffered solution at 37℃ for various time. Human dermal fibroblasts were seeded on PLGA scaffolds with different initial copolymer compositions and incubated for various time points. Cell adhesion efficacy, proliferation rate, and total collagen content were analyzed and cell morphology on the scaffolds was observed using scanning electron microscopy. The results showed that with the increase of PLA ratio, mechanical strength of the scaffolds increased, whilst the degradation rate decreased, but the changes were not lineal. PLGA 70:30 scaffolds got the highest mechanical strength, and there were no significant difference on the degradation rate between PLGA 70:30 and 80:20. PLGA scaffolds with different initial copolymer compositions had good cytocompatibility, showing high cell adhesion efficacy, fast proliferation rate and stretched cell morphology with no significant difference. A large amount of extracellular matrix was secreted and after 7 days of culture, cell nearly covered all the surface of the scaffolds. Based on these results, the study drew the conclusion that the copolymer compositions of PLGA affected the mechanical, degradation and biological properties of the scaffolds subtly but significantly. This would be helpful for choosing PLGA scaffold materials for constructing tissue.