Department of Cytology, Histology and Embryology, Faculty of Biology, St. Kliment Ohridski University of Sofia, Sofia 1164, Bulgaria.
Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
Int J Mol Sci. 2019 Mar 15;20(6):1313. doi: 10.3390/ijms20061313.
The wettability of silicone hydrogel (SiHy) contact lens (CLs) is crucial for the pre-lens tear film stability throughout the day. Therefore, sessile drop and captive bubble setups were used to study the advancing and receding water contact angles (CA) of four SiHy materials: narafilcon A (TE), senofilcon A (AOD), stenfilcon A (MD), and delefilcon A (DT). TE and AOD have 48% and 38% water content, respectively, and no surface coating. MD (54% water) implements "smart chemistry" with just 4.4% bulk silicone content, while DT has >80% water at its surface. These SiHy were subjected to continuous blink-like air exposure (10 s)/rehydration (1s) cycles for 0, 1, 2, 3, 4, 6, 8, 10, 12, 14, and 16 h. The advancing CA, which measures the rehydration propensity of the CL surface, proved to be the most sensitive parameter to discriminate between the samples. The order of performance for the entire time scale was DT > MD >> AOD ≥ TE. The extended desiccation/rehydration cycling increased the differences between the CA of DT and MD compared to AOD and TE. This suggests that the low Si surface content and the high surface hydration are major determinants of SiHy wettability.
硅水凝胶（SiHy）隐形眼镜（CL）的润湿性对于整天的预隐形泪膜稳定性至关重要。因此，采用静态液滴和被俘获气泡装置研究了四种 SiHy 材料的前进和后退水接触角（CA）：narafilcon A（TE）、senofilcon A（AOD）、stenfilcon A（MD）和 delefilcon A（DT）。TE 和 AOD 的含水量分别为 48%和 38%，且没有表面涂层。MD（54%水）采用“智能化学”，仅含 4.4%的体硅含量，而 DT 的表面水含量>80%。这些 SiHy 经历了 0、1、2、3、4、6、8、10、12、14 和 16 小时的连续眨眼样空气暴露（10 s）/再水化（1 s）循环。前进 CA 可衡量 CL 表面的再水化倾向，被证明是区分样品的最敏感参数。在整个时间尺度上，性能顺序为 DT>MD>>AOD≥TE。延长的干燥/再水化循环增加了 DT 和 MD 与 AOD 和 TE 之间 CA 的差异。这表明低 Si 表面含量和高表面水合作用是 SiHy 润湿性的主要决定因素。
