负载PEO-b-PLL/DNA-TGF beta1粒子的PLGA/纤维蛋白凝胶复合支架的制备及其体外干细胞诱导分化性能

Preparation of Hybrid Scaffold of PLGA Sponge/Fibrin Gel/BMSCs/DNA Complexes with Enhanced Property for BMSCs Differentiation

采用粒径分布在450～600μm的无规明胶颗粒为致孔剂制备乳酸-乙醇酸共聚物(PLGA)海绵体,以纤维蛋白凝胶为负载聚氧化乙烯-b-聚赖氨酸(PEO-b-PLL)/DNA粒子和骨髓间充质干细胞(BMSCs)的传递介质,通过负压将其导入PLGA多孔支架,在凝血酶和Ca2+作用下原位凝胶,构建了一种负载PEO-b-PLL/DNA粒子的PLGA/纤维蛋白凝胶/BMSCs复合支架。系统地表征了复合支架的形貌及微结构。考察了PLGA海绵体和纤维蛋白水凝胶的体外降解性能以及PEO-b-PLL/DNA粒子的体外释放行为。重点研究了BMSCs在复合支架中的形态、活性和向软骨细胞分化等生物学性能。研究结果表明:PLGA海绵体具有高孔隙率、高孔连通性;纤维蛋白凝胶均匀填充在PLGA海绵体孔隙中,而PEO-b-PLL/DNA粒子分布在纤维蛋白凝胶三维结构中;体外降解实验显示,8周后PLGA分子量为初始分子量的50%以下,而伴随着纤维蛋白凝胶的快速降解,PEO-b-PLL/DNA粒子被快速释放到溶液中;体外细胞培养结果显示,BMSCs在复合支架体系中具有良好的形态、活性和分泌软骨细胞外基质的能力。

A poly （lactide-co-glycolide） （PLGA） sponge filled with fibrin gel, bone mesenchymal stem cells （BMSCs） and poly （ethylene oxide）-b-poly （L-lysine） （PEO-b-PLL）/pDNA-TGF-131 complexes was fabricated. The microstructure of the hybrid scaffold, the in witro degradation behavior of the PLGA scaffold and fibrin gel and the release profile of PEO-b-PLL/DNA complexes from the hybrid scaffold were studied. The morphology, viability and the property of differentiating into chondrocyte of BMSCs were investigated by in witro cell culture. According to the results, the hybrid scaffold is consisted of a porous PLGA sponge filled with the fibrin gel, which displays a 3D network of nano-fibers. Due to the fast degradation of fibrin gel, almost 85 % of all the PEO-b-PLL/DNA complexes ＇are released from the hybrid scaffold within 3 days. Cell culture revealed that BMSCs in the hybrid scaffold can proliferate well along with the time and show an enhanced property of differentiating into chondrocyte compared to the scaffold without PEO-b-PLL/DNAcomplexes.