Korogiannaki Myrto, Zhang Jianfeng, Sheardown Heather
1 Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada.
2 264790 Saint-Gobain Northborough Research and Development Center , Northboro, MA, USA.
J Biomater Appl. 2017 Oct;32(4):446-462. doi: 10.1177/0885328217733443.
Discontinuation of contact lens wear as a result of ocular dryness and discomfort is extremely common; as many as 26% of contact lens wearers discontinue use within the first year. While patients are generally satisfied with conventional hydrogel lenses, improving on-eye comfort continues to remain a goal. Surface modification with a biomimetic, ocular friendly hydrophilic layer of a wetting agent is hypothesized to improve the interfacial interactions of the contact lens with the ocular surface. In this work, the synthesis and characterization of poly(2-hydroxyethyl methacrylate) surfaces grafted with a hydrophilic layer of hyaluronic acid are described. The immobilization reaction involved the covalent attachment of thiolated hyaluronic acid (20 kDa) on acrylated poly(2-hydroxyethyl methacrylate) via nucleophile-initiated Michael addition thiol-ene "click" chemistry. The surface chemistry of the modified surfaces was analyzed by Fourier transform infrared spectroscopy-attenuated total reflectance and X-ray photoelectron spectroscopy. The appearance of N (1s) and S (2p) peaks on the low resolution X-ray photoelectron spectroscopy spectra confirmed successful immobilization of hyaluronic acid. Grafting hyaluronic acid to the poly(2-hydroxyethyl methacrylate) surfaces decreased the contact angle, the dehydration rate, and the amount of nonspecific sorption of lysozyme and albumin in comparison to pristine hydrogel materials, suggesting the development of more wettable surfaces with improved water-retentive and antifouling properties, while maintaining optical transparency (>92%). In vitro testing also showed excellent viability of human corneal epithelial cells with the hyaluronic acid-grafted poly(2-hydroxyethyl methacrylate) surfaces. Hence, surface modification with hyaluronic acid via thiol-ene "click" chemistry could be useful in improving contact lens surface properties, potentially alleviating symptoms of contact lens related dryness and discomfort during wear.
因眼干和不适而停止佩戴隐形眼镜的情况极为常见；多达26%的隐形眼镜佩戴者在第一年就停止使用。虽然患者通常对传统水凝胶镜片感到满意，但提高眼部舒适度仍是一个目标。据推测，用仿生的、对眼睛友好的湿润剂亲水层进行表面改性可改善隐形眼镜与眼表的界面相互作用。在这项工作中，描述了接枝有透明质酸亲水层的聚甲基丙烯酸2-羟乙酯表面的合成与表征。固定化反应涉及通过亲核试剂引发的迈克尔加成硫醇-烯“点击”化学将硫醇化透明质酸（20 kDa）共价连接到丙烯酸化聚甲基丙烯酸2-羟乙酯上。通过傅里叶变换红外光谱-衰减全反射和X射线光电子能谱分析改性表面的表面化学。低分辨率X射线光电子能谱光谱上N（1s）和S（2p）峰的出现证实了透明质酸的成功固定。与原始水凝胶材料相比，将透明质酸接枝到聚甲基丙烯酸2-羟乙酯表面降低了接触角、脱水率以及溶菌酶和白蛋白的非特异性吸附量，这表明开发出了具有更好润湿性、保水和防污性能的表面，同时保持了光学透明度（>92%）。体外测试还表明，人角膜上皮细胞在接枝有透明质酸的聚甲基丙烯酸2-羟乙酯表面具有优异的活力。因此，通过硫醇-烯“点击”化学用透明质酸进行表面改性可能有助于改善隐形眼镜的表面性能，潜在地减轻佩戴过程中与隐形眼镜相关的干眼和不适症状。
