Purchase this article with an account.
L. Hartmann, S. E. Beck, L.-L. Zheng, C.-Y. Kim, P. Huie, J. Noolandi, J. Cochran, C. Ta, C. W. Frank, Stanford-SERI Study Group Program; Designing an Artificial Cornea - Longterm Stability and in vivo Testing. Invest. Ophthalmol. Vis. Sci. 2009;50(13):1517.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We designed an artificial cornea based on a novel hydrogel material consisting of two interpenetrating polymer networks (IPNs) made from poly(ethylene glycol) (PEG) and poly(acrylic acid) (PAA). In this study we investigate the long term stability of such a polymer under in vivo conditions.
Two IPN systems were synthesized: A PEG-diacrylate system being susceptible to hydrolysis and a PEG-diacrylamid system being stable under hydrolytic conditions. In order to evaluate long term stability different degradation tests were performed including accelerated hydrolysis, autoclaving and enzymatic degradation mimicking in vivo conditions. All gels were then analyzed by swelling/weight loss measurements, mechanical testing as well as cytotoxicity tests.
We demonstrate that only the PEG-diacrylamid system, as opposed to the PEG-diacrylate system, is stable and therefore suitable as an artificial cornea. The two systems undergo different degradation reactions. The PEG-diacrylamid system also allows for effective sterilization using autoclaving, a technique often weakening hydrogels by partial degradation. Furthermore we can correlate the long term stability with the overall biocompatibility of the implant in a rabbit model. The PEG-diacrylate implant caused inflammation and turbidity following implantation in vivo. In contrast, the redesigned, long term stable material of PEG-diacrylamid system were biologically compatible and remained optically clear for up to 4 months following after implantation.
A novel, stable hydrogel material was successfully designed as an artificial cornea. Stability of the hydrogel was demonstrated by the physical property of the material as well as in vivo biocompatibility testing.Support: NIH Grant R01 EY016987-01A1, Singapore Eye Research Institute (SERI), NIH Grant 5T90 DK070103-03. This work is part of the Stanford-SERI Study Group Program.
This PDF is available to Subscribers Only