REG增强的脱细胞猪角膜/聚甲基丙烯酸羟乙酯原位一体式全层复合人工角膜

REG-augmented decellularized porcine cornea/hydroxyethyl methacrylate in situ integrated composite artificial cornea

背景:目前用于全层移植的人工角膜缺乏生物活性及力学适配性,组合式人工角膜存在镜柱和周围组分间的界面问题。目的:在脱细胞猪角膜原位固化制备具有多肽增强、匹配自然角膜机械强度、良好透光性的一体式全层人工角膜。方法:使用非离子型脱细胞试剂Triton X-100与超声冻融及超级核酸酶相结合的方法制备脱细胞猪角膜,将聚甲基丙烯酸羟乙酯单体与光引发剂同时引入脱细胞猪角膜中,通过紫外滤光片遮住除中心区域以外的部分,使用275 nm紫外光引发中央区域聚合,除去未反应的单体及引发剂后得到中央光学区,同理在后板层固化隔水区,最后引入REG活性多肽,得到原位一体式全层人工角膜,表征人工角膜的物理性能、力学性能、透光性、降解性能及体内外生物相容性。结果与结论:①实验在脱细胞猪角膜的中央区域采用聚甲基丙烯酸羟乙酯原位构建了一个具有聚合物和胶原纤维共存的光学区,扫描电镜下可见人工角膜的上表面较为粗糙且轮廓不规则,具有明显的凹陷和突起结构,下表面相对光滑;该人工角膜具有接近于天然角膜的力学性能,光学区透光率达到自然角膜的80%,浸泡于含胶原酶的PBS无菌溶液中可较好地保留固化光学区和隔水区,维持角膜的基本结构;该人工角膜具有良好的细胞相容性,能够为细胞提供适宜的黏附生长环境,有利于角膜上皮细胞的迁移和黏附,促进血管内皮细胞的生长和新生血管的形成,促进上皮化过程;人工角膜植入SD大鼠皮下12周后具有良好的生物相容性和安全性,可降低植入初期的急性炎症反应;②结果表明,实验制备的一体式全层人工角膜具有作为全层人工角膜支架材料的潜力。

BACKGROUND:Currently,artificial corneas used for full-thickness transplantation lack biological activity and mechanical adaptability.Composite artificial corneas face interface issues between the corneal button and surrounding components.OBJECTIVE:To prepare an integrated artificial cornea with peptide enhancement,matched mechanical strength to natural cornea,and excellent transparency via in situ ultraviolet light curing of decellularized porcine cornea.METHODS:Non-ionic decellularization reagent Triton X-100 combined with ultrasonic freeze-thawing and super nucleases was utilized to prepare decellularized porcine cornea.Hydroxyethyl methacrylate monomer and photoinitiator were introduced into the decellularized porcine cornea simultaneously.Ultraviolet light with a filter was used to cover the peripheral region except for the central area,where polymerization was initiated using 275 nm ultraviolet light.After removal of unreacted monomers and initiators,the central optical zone was obtained.Similarly,the posterior lamellar layer was polymerized to form the hydrophobic barrier zone.Finally,REG active polypeptide was introduced to obtain in situ integrated full-layer artificial cornea.The physical properties,mechanical properties,transparency,degradation properties and in vivo and in vitro biocompatibility of artificial cornea were characterized.RESULTS AND CONCLUSION:(1)An optical region with the co-existence of polymer and collagen fibers was constructed in situ using hydroxyethyl methacrylate in the central region of decellularized porcine cornea.Under scanning electron microscopy,the upper surface of the artificial cornea was rough and irregular,with obvious concave and convex structure,and the lower surface was relatively smooth.The artificial cornea had mechanical properties close to those of natural cornea.The transparency of the optical zone reached 80%of that of the natural cornea.After soaking in PBS aseptic solution containing collagenase,it could preserve the solidified optical region and hydrophobic barrier zone,and maintain the basic structure of cornea.The artificial cornea had good cytocompatibility,could provide a suitable adhesion and growth environment for cells,was conducive to the migration and adhesion of corneal epithelial cells,promoted the growth of vascular endothelial cells and the formation of new blood vessels,and promoted the epithelialization process.The artificial cornea had good biocompatibility and safety after 12 weeks of subcutaneous implantation in SD rats,and could reduce the acute inflammatory reaction at the initial stage of implantation.(2)The results show that the integrated full-layer artificial cornea prepared by the experiment has the potential as a full-layer artificial cornea scaffold.