School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada.
J Biomater Appl. 2013 Sep;28(3):323-33. doi: 10.1177/0885328212446936. Epub 2012 May 4.
Conventional and silicone hydrogels as models for contact lenses were prepared to determine the effect of the presence of hyaluronic acid on lysozyme sorption and denaturation. Hyaluronic acid was loaded into poly(2-hydroxyethyl methacrylate) and poly(2-hydroxyethyl methacrylate)/TRIS--methacryloxypropyltris (trimethylsiloxy silane) hydrogels, which served as models for conventional and silicone hydrogel contact lens materials. The hyaluronic acid was cross-linked using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide in the presence of dendrimers. Active lysozyme was quantified using a Micrococcus lysodeikticus assay while total lysozyme was determined using 125-I radiolabeled protein. To examine the location of hyaluronic acid in the gels, 6-aminofluorescein labeled hyaluronic acid was incorporated into the gels using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide chemistry and the gels were examined using confocal laser scanning microscopy. Hyaluronic acid incorporation significantly reduced lysozyme sorption in poly(2-hydroxyethyl methacrylate) (p < 0.00001) and poly(2-hydroxyethyl methacrylate)/TRIS--methacryloxypropyltris (trimethylsiloxy silane) (p < 0.001) hydrogels, with the modified materials sorbing only 20% and 16% that of the control, respectively. More importantly, hyaluronic acid also decreased lysozyme denaturation in poly(2-hydroxyethyl methacrylate) (p < 0.005) and poly(2-hydroxyethyl methacrylate)/TRIS--methacryloxypropyltris (trimethylsiloxy silane) (p < 0.02) hydrogels. The confocal laser scanning microscopy results showed that the hyaluronic acid distribution was dependent on both the material type and the molecular weight of hyaluronic acid. This study demonstrates that hyaluronic acid incorporated as a wetting agent has the potential to reduce lysozyme sorption and denaturation in contact lens applications. The distribution of hyaluronic acid within hydrogels appears to affect denaturation, with more surface mobile, lower molecular weight hyaluronic acid being more effective in preventing denaturation.
以传统型和硅水凝胶隐形眼镜为模型，研究透明质酸的存在对溶菌酶吸附和变性的影响。将透明质酸载入聚（2-羟乙基甲基丙烯酸酯）和聚（2-羟乙基甲基丙烯酸酯）/TRIS-甲基丙烯酰氧基丙基三（三甲氧基硅基）硅烷水凝胶中，作为传统型和硅水凝胶隐形眼镜材料的模型。在存在树状聚合物的情况下，使用 1-乙基-3-（3-二甲基氨基丙基）碳二亚胺将透明质酸交联。采用溶壁微球菌法测定活性溶菌酶，采用 125I 放射性标记蛋白法测定总溶菌酶。为了研究透明质酸在凝胶中的位置，使用 1-乙基-3-（3-二甲基氨基丙基）碳二亚胺化学法将 6-氨基荧光素标记的透明质酸载入凝胶中，并使用共聚焦激光扫描显微镜进行观察。透明质酸的掺入使聚（2-羟乙基甲基丙烯酸酯）（p < 0.00001）和聚（2-羟乙基甲基丙烯酸酯）/TRIS-甲基丙烯酰氧基丙基三（三甲氧基硅基）硅烷（p < 0.001）水凝胶中的溶菌酶吸附显著减少，改性材料的吸附量分别仅为对照材料的 20%和 16%。更重要的是，透明质酸还降低了聚（2-羟乙基甲基丙烯酸酯）（p < 0.005）和聚（2-羟乙基甲基丙烯酸酯）/TRIS-甲基丙烯酰氧基丙基三（三甲氧基硅基）硅烷（p < 0.02）水凝胶中的溶菌酶变性。共聚焦激光扫描显微镜结果表明，透明质酸的分布既依赖于材料类型，也依赖于透明质酸的分子量。本研究表明，作为润湿剂掺入的透明质酸具有减少隐形眼镜应用中溶菌酶吸附和变性的潜力。透明质酸在水凝胶中的分布似乎影响变性，具有更高表面流动性和更低分子量的透明质酸在防止变性方面更有效。
