角膜内不同部位植入壳聚糖-胶原复合膜的生物相容性

Biocompatibility assessment of chitosan-collagen membrane at different intracorneal implantation positions

背景:角膜基质层间植入是评价材料角膜内生物相容性的理想模型,但将材料植入角膜基质层间的位置不同,可能会影响材料的降解以及角膜的代谢,最终影响到材料在角膜内生物相容性评价结果。目的:观察壳聚糖胶原复合膜(胶原含量为30%)植入兔角膜不同部位基质层的组织相容性。方法:制备厚度为20μm的壳聚糖胶原复合膜。将新西兰大白兔以抽签法随机分为两组:一组角膜周边基质层间植入壳聚糖胶原复合膜材料;另一组角膜中央基质层间植入壳聚糖胶原复合膜材料。裂隙灯显微镜观察材料植入后眼表及前房的反应、材料植入部位角膜和材料的相互反应及植入部位角膜透明性改变。6周后取角膜做组织切片,观察植入部位角膜组织和材料的组织学改变。结果与结论:角膜周边植入组的复合膜逐渐降解,最终完全降解,并对角膜结构无明显影响,显示了良好的角膜组织相容性;中央植入组复合膜植入早期眼表稳定,也显示了良好的生物相容性,但是2周过后伴随着材料的缓慢降解,材料周边变得不透明,伴随着炎症细胞浸润,最终在第34,42天分别有一只发生角膜溶解。结果说明薄的壳聚糖胶原复合膜材料透明性好、力学性能匹配,植入角膜周边基质层间后在短时间内能完全降解,适宜作为角膜修复材料,特别是作为角膜缘干细胞的载体可以用来修复角膜缘干细胞损伤引起的角膜疾病。

BACKGROUND：Corneal intrastromalcorneal implantation is the ideal model for biocompatibility assessment of the implanted materials,but different implanting positions may influence the material degradation and corneal metabolism,finally impacting on the biocompatibility evaluation of intracorneal implantation.OBJECTIVE：To investigate the histocompatibility of chitosan-collagen membrane（30% collagen） implanted into different positions of rabbit cornea.METHODS：Chitosan-collagen composite membrane at 20-μm thick was prepared.New Zealand rabbits were randomized divided into two groups：peripheral corneal intra-stroma implantation group of chitosan-collagen membrane;central corneal intra-stroma implantation group of the membrane.Slitlamp microscopy examinations were performed to observe the reaction of ocular surface and anterior chamber after the implantation of the membrane,the interaction between cornea and implanted membrane,the transparency of cornea were also observed.Cornea slices were obtained 6 weeks later to observe the histological changes of cornea and implanted materials at implantation site.RESULTS AND CONCLUSION：In peripheral corneal intra-stroma implantation group,the complex membrane gradually degraded and finally completed degraded,and the corneal structure was not markedly influenced,indicating good histocompatibility of corneal tissues.In central corneal intra-stroma implantation group,the ocular surface was stable at early stage of the implantation,also suggesting good biocompatibility.Two weeks later,the material rim became untransparent with the materials gradually degraded.At days 34 and 42,each one cornea melted accompanying inflammatory cells infiltration.Results demonstrated that thin chitosan-collagen composite membrane has good transparency and matched mechanical properties,materials implanted into the peripheral cornea may completely degrade within a short time.It may be used as a corneal restorative material,especially as the carrier of corneal limbal stem cells to repair corneal damage.