Purchase this article with an account.
Alonzo Cook, Matthew Skinner, Jun Li, Christopher Loose, Karen Schultz, Zheng Zhang; Improving The Wettability Of Silicone Hydrogel Contact Lenses. Invest. Ophthalmol. Vis. Sci. 2012;53(14):6096.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We have developed stable, extremely hydrophilic polymers that reduce fouling and improve surface wettability on medical devices. Recently, this polybetaine chemistry was applied to a long-term vascular catheter and shown to reduce the in vitro attachment of platelets and thrombus even after 60 days of blood product exposure. The technology has now been adapted to silicone hydrogel contact lenses to improve wettability. The hypothesis of this study is that by adding polybetaine to the surface of contact lenses, the advancing contact angle will be substantially decreased.
Silicone hydrogel contact lenses were surface modified using a one-step controlled polymerization process. Contact lenses with biocompatible polybetaine-based polymers were compared to unmodified (control) lenses. The surface characteristics were analyzed with surface staining, SEM-EDS, XPS, dynamic contact angle, and ATR-FTIR. The stability of the modification was evaluated under oxidative conditions, after autoclaving, and after rubbing.
Advancing contact angles were decreased by approximately 50o. Unmodified silicone hydrogel lenses (n=25) had an advancing contact angle of 80o +/- 3o and a receding angle of 29o +/- 2o. Semprus modified lenses (n=3) had an advancing contact angle of 27o +/- 2o and a receding angle of 26o +/- 2o. The surface modification had no effect on the bulk properties including clarity, dimensions, and mechanical properties. The modification was stable to oxidative solutions, sterilization and mechanical challenges.
The polybetaine surface modification provides a novel and viable avenue for significantly improving the wettability of silicone hydrogel contact lenses without affecting their bulk properties. The advancing contact angle was substantially decreased while the receding contact angle was predictably maintained at a low level. The one-step process method is adaptable to various silicone hydrogel contact lenses with different formulations.
This PDF is available to Subscribers Only