HA表面改性人工角膜钛支架生物相容性动物实验研究

Biocompatible study of hydroxyapatite modified titanium skirt for keratoprosthesis in vivo

目的经羟基磷灰石(hydroxyapatite,HA)表面改性的三襻式人工角膜钛支架植入兔角膜板层探讨其与角膜组织的生物相容性及组织愈合情况。方法24只新西兰白兔随机分为A、B、C3组,A组(9只)及B组(9只)分别于右眼角膜板层植入HA表面改性后的三襻式人工角膜钛支架(HA-Ti)及人工角膜钛支架(Ti);C组(6只)为手术对照组,仅制备囊袋不植入支架。观察人工角膜支架的生物相容性及新生血管生长情况,并分别于术后2周、4周、16周取材,行组织病理学及支架表面组织扫描电镜观察。结果观察期间A、B组均未见角膜感染、溶解、支架排出。早期实验组角膜有水肿及新生血管长入,A组新生血管明显多于B组。组织学观察术后2周,A组炎症细胞浸润重于对照C组及B组(P<0.05);4周和16周时A、B和C组各组间炎症反应无明显差别(P>0.05)。A组支架周围基质成纤维细胞增生显著,术后2周、4周A组和B组成纤维细胞增生均多于对照C组(P<0.05),且A组增生明显多于B组(P<0.05);术后16周时各组间差异无统计学意义(P>0.05)。扫描电镜HA-Ti支架表面角膜组织黏附好,胶原纤维与支架连接紧密。结论HA表面改性三襻式钛支架促进角膜血管化,有利于人工角膜的稳定,使人工角膜支架具有良好生物相容性及促进组织界面愈合能力。

Objective To explore biocompatibility and biohenltng characteristics of a hydroxyapatite syrfaced-modified titanium keratoprosthesis that implanted into the corneal stroma of rabbits. Methods Twenty-four New Zealand white rabbits were randomly divided into A（9） ,B（9） and C（6） groups. Surgery was performed in right eye of all animals. Skirts of hydroxyapatite-titanium skirt（HA-Ti） and titanium skirt （ Ti ） were respectively inserted into the corneal stroma of rabbit of experimental group A and group B; Only a corneal pocket was made without implantation in control group C. Corneal edema and corneal neovasodarization were observed at scheduled times after operation; Animals were sacrificed at 2 weeks,4 weeks and 16 weeks after operation and the cornea were removed and examined by light microscopy; The surface of skirt was observed under scanning electron microscope. Results During the stoding period, all skirts were stable without infection solution and exclusion various. Different degree of cornea edema and corneal neovascularization was revealed after surgery. The neovasodnrization of rabbit cornea in group A was more obvious than that in group B. On the 2nd week,the inflammatory reaclion inA group was greater than that in C and B groups（P 〈 0.05） .There wasn＇t significant difference among A,B and C groups at 4 weeks and 16 weeks post-opera tion. The number of fibroblasts in group A and B were markedly more than that of group C at 2 weeks and 4 weeks post-operation（P 〈 0.05 ）. There was no significant difference between each two groups at 16 weeks after operation（P〉0.05）. The extracellular matrix deposited on surface of HA-Ti skirt was more dense and tight. Conclusion Hydroxyapatite modified titanium skirt for keratoprosthesis promoted the corneal neovasularization and improve the interracial biointegration of skirt and host cornea.