Artificial corneas have potential to benefit millions worldwide who are blind due to corneal disease. Although cornea! prosthetics have been available for many years in various forms, their widespread application has been limited by their propensity to opacify or extrude. The overall goal of this research is to develop the next generation of artificial cornea with improved in vivo stability through enhanced resistance to protein adsorption and support for both surfaceepithelialization and peripheral tissue integration. We hypothesize that intrinsically protein-resistant materials that have been engineered for site-specific cell growth will form the basis of a sustainable artificial cornea. The proposed work is an integrated evaluation of an innovative, photolithographically fabricated construct specifically designedto addressthe major deficiencies of current corneal prostheses. Our design consists of a mechanically enhanced poly(ethylene glycol)/poly(acrylic acid) (PEG/PAA) double network """"""""core"""""""" optic component that will support surface epithelialization but resist bulk protein adsorption, and an interpenetrating, micropatterned poly(hydroxyethylacrylate) (PHEA) """"""""skirt"""""""" that will promote robust stromal tissue integration. This design strategy is attractive because 1) PEG/PAA is an excellent material for a central optic due to its unique combination of transparency, strength, permeability, and resistance to protein adsorption, 2) PHEA is a hydrophilic, cytocompatible, and rapidly photopolymerizing network that can be patterned with high fidelity and can interpenetrate with PEG and PAA, and 3) photolithographic techniques can be used to promote site-specific surface epithelialization and bulk tissue integration within these hydrogels with micron-order precision. Combining in vitro and in vivo assessments of the prototype materials' mechanical and molecular/cellular interfacial properties, the Specific Aims are to: 1. Elucidate the biomechanical and interfacial properties of artificial cornea component materials through dynamic mechanical analysis, protein adsorption assays, and in vivo corneal implantation. 2. Characterize and control surface epithelialization on PEG/PAA central optics by in vitro measurement of surface bioactivity, cell migration and adhesion, and in vivo epithelialization studies. 3. Determine the skirt design for optimal stromal tissue integration by evaluating in vitro and in vivo stromal wound healing within photolithographically patterned, microperforated hydrogel arrays.
