组织工程化角膜基质的构建与移植实验

Study on reconstruction and transplantation of tissue-engineered corneal stroma

目的探讨以可降解高分子材料聚羟基乙醇(PLGA)为支架体外构建组织工程化角膜基质的可行性.方法将培养的角膜基质细胞接种于具微孔的可降解高分子材料PLGA内,构建成组织工程化细胞-PLGA复合物,将该复合物移植到兔眼角膜基质层间.分别于移植后1、2周,1、2、3、4个月取材,光学显微镜、电镜观察细胞与PLGA材料的结合情况.裂隙灯显微镜和组织切片检查组织工程化角膜基质的透明性、可降解性以及生物反应性.结果角膜基质细胞能与PLGA高分子材料较好地结合,移植到兔眼角膜层间的组织工程化角膜基质7 d后呈半透明,2周见新生血管从角膜缘向植片方向生长,1个月开始材料降解,3～4个月时大部分材料降解,且新生血管减少,但是移植物呈半透明状.结论PLGA虽然具有组织相容性好、无毒、无免疫性和可降解的特性,但不适合作为构建要求具有很好透明性的角膜组织的支架材料.

Objective To investigate the feasibility of using poly lactic co glycolic acid (PLGA)as corneal stroma scaffolds in vivo. Methods Corneal stroma tissue was reconstructed by coculturing corneal keratocytes with PLGA.The complex was transplanted intralamellarly into rabbit stromal pocket,and corneal stromal transparency,absorbability and inflammatory reaction were observed by slit lamp and tissue section.The cell ingrowth was examined with light microscope and electron microscope at 1,2 weeks and 1,2,3,4 months after transplantation. Results The corneal keratocytes firmly attached to the polymer,and tissue engineered stroma was transparent in day 7 after implantation.Neovascularization was observed in limbus 2 weeks after the implantation.PLGA began to degrade at 1 month.Most of the material was absorbed and there was little neovascularization,but the explant was still translucent 3-4 months after the implantation. Conclusion PLGA has good histocompatibility,little toxicity and biodegradability,but it is not suitable for reconstructing corneal tissue with normal function.