Background Corneal contact lens have been widely used in vitrectomy.The corneal ring accompanying with the contact lens therefore is also much concerned.We designed a sutureless silicone corneal ring to renew a suturing?ring,but its detection of physicochemical properties and hiocompatihility is necessary for clinical application. Objective This study was to investigate the physicochemical properties and biocompatibility of the newly designed sutureless silicone corneal ring. Methods The Shore hardness,tensile stress-strain tests,tear strength,transmittance and the haze of the novel silicone ring were tested.The bioeompatibility of sutureless silicone corneal ring to corneal epithelial cells was evaluated by determining cytotoxieity.The ring was implanted into the counjunctival soc of 6 Japanese white rabbits for 4 hours to determine its stimulation response by measuring the area of corneal fluorescence staining,and then the ring was placed on the skin surface of 6 SD rats for 4 hours to assess the presence of allergic reaction by calculating the swelling area of skin. Results The new sutureless silicone corneal ring showed good physiological features with a Shore hardness of 63.4 degree,tensile strength more than 5.86 MPa,elongation＞100%and tear strength 34 kN/m.The transmittance of 3 legs in the ring was more than 93%;however,the haze was less than 0.1%.Cytotoxicity of the ring was 3.1 1×10-6%.No obvious corneal fluorescence staining was seen at any time point in all the rabbit eyes in the stimulating test.Furthermore,there was not any skin swelling in various time points in all the SD rats in the allergy test. Conclusion The physicochemical properties of the silastic used in our newly designed sutureless silicone cornea ring can meet the demands of the ring.The biological evaluation complies with the ISO i0993-1 international standards and meets the demands of the organism.Thus,it is all ideal material to use in constructing the corneal ring.%背景玻璃体切割术中,角膜接触镜已得到广泛使用,配合接触镜使用的角膜环的改进也倍受关注.本课题组研制了一种新型免缝线的角膜环,其理化特性及生物相容性研究能为临床应用提供必要的理论依据.目的检测新型免缝线硅胶角膜环的理化性能特征和生物相容性.方法对新型免缝线硅胶角膜环进行邵氏硬度测试、拉伸应力应变测试、撕裂强度测试、透光率和雾度测试.收集人角膜上皮细胞进行细胞毒性分析以评价新型免缝线硅胶角膜环的生物相容性.6只成年白兔结膜囊内放置硅胶环产品,于6、24、48、72 h后记录白兔角膜荧光素着色面积以对硅胶环产品的刺激反应进行评价.6只成年SD大鼠备皮后皮肤表面放置硅胶环,并于6、24、48、72 h后测量SD大鼠局部皮肤红肿的面积以评价其过敏反应.结果新型免缝线硅胶角膜环的邵氏硬度为63.4度,拉伸强度大于5.86 MPa,伸长率大于100%,撕裂强度为34 kN/m.新型免缝线硅胶角膜环3爪的透光率均大于93%,而雾度均小于0.1%.免缝线硅胶角膜环对角膜细胞的细胞毒性测试值为3.11×10-6%.结膜囊内放置免缝线硅胶角膜环6、24、48、72 h,所有的兔眼均未见角膜荧光素着色.实验前及免缝线硅胶角膜环置于SD大鼠皮肤面后6、24、48、72 h,所有的SD大鼠皮肤均未见红肿.结论采用的硅橡胶理化特性能满足角膜环的制作要求,生物学评价符合ISO 10993-1评估医疗器材生物相容性的国际标准和生物体的要求,是制备角膜环较为理想的材料.
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