软性一体式PHEMA人工角膜植入碱烧伤兔角膜的电镜观察

New soft one-piece PHEMA keratoprosthesis implanted into alkali burned rabbit corneas: an electron microscopy observation

目的研究与评估新型软性一体式PHEMA人工角膜与碱烧伤兔角膜生物愈合的电镜特点。方法制备兔角膜碱烧伤模型后,将软性一体式PHEMA人工角膜植入,分别于4周、8周、16周和24周后取裙边组织进行扫描电镜和透射电镜检查。结果 4周时,即有新生组织长入孔隙之中,材料与角膜组织结合紧密;迁徙入材料内的角膜细胞胞浆富含粗面内质网等细胞器,显示旺盛的合成功能;其周围有胶原、蛋白多糖等细胞外基质的沉积,并且显示出从新生到成熟的动态变化。结论新型人工角膜的孔隙支架材料,能够允许角膜细胞及周围组织迁徙、增殖并分泌沉积细胞外基质,从而达到材料与组织的生物愈合。

Objective To evaluate the histopathological results of the porous skirt of new one-piece keratoprosthesis （ KPros） made of PHEMA implanted to alkali burned rabbit corneas.Methods The KPros were inserted into the la-mellar pocket of alkali-burned corneas and the corneas were observed clinically, histologically and ultrastructurally at va-rious time, and followed for up to 28 weeks.Results Histopathologic study suggested that mild inflammatory reaction and no calcification was seen in all specimens.Fibroblasts and deposition of collagen were found in the pores of the discs two weeks after implantation and stable connection with cornea would formed by 16 weeks.TEM （ Transmission Electron Microscope） results showed that abundant endoplasmic reticulum could be observed in fibroblast cytoplasm at week 4, which indicated the strong synthetic activity of fibroblast cells.Also, deposition of proteoglycans and other ex-tracellular matrix around the material could be observed under TEM.By week 16, there were large amounts of orderly arranged collagen fiber around the material.The fibroblasts in the pores looked healthy and functionally active under TEM.Conclusion Along with the proliferation of surrounding tissue, corneal cells could proliferate and migrate into the porous skirt of PHEMA which was implanted into alkali burned rabbit corneas.Corneal cells and other cells could also secrete extracellular matrix and promote its deposition to accelerate the formation of new organizations, and strengthen the connection between cornea and material.