A novel intralamellar semi-bioresorbable keratoprosthesis-Part B: Surface functionalization and physico-chemical characterization toward site-specific cellular activity

In this article, site-specific functionalized keratoprosthesis (KPro) was accomplished to meet epithelial on-growth on the anterior optical surface, inhibit cell adhesion on the posterior optic surface, and promote cell ingrowth at the peripheral tissue-haptic-flange interface toward tissue integration. Gelatin immobilization on PC4 hydrogel surfaces was achieved through acid hydrolysis followed by EDC/NHS chemistry, and polyethylene glycol-diacrylate (PEGDA)-modified inter-penetrating network (IPN) surfaces were prepared using photo-polymerization of ethylene glycol-diacrylate (EGDA) for enhancing and inhibiting cellular growth, respectively. The surface chemical structures of modified hydrogels were characterized using attenuated total reflectance-infrared (ATR-IR) spectroscopy and a bicinchoninic acid (BCA) protein adsorption assay. Further, suitable differentially functionalized surfaces were prepared and characterized using the universal testing machine (UTM), refractometer, atomic force microscopy (AFM), and contact angle measurements to understand mechanical, optical, surface morphological, and wettability properties, respectively. Finally, in vitro site-specific cell adhesion, cell inhibition, and cell ingrowth functionalities were tested using isolated goat corneal limbal epithelial stem cells and corneal stromal fibroblast cells, respectively. Overall, the two connective articles represent a successful endeavor to develop a more esthetically pleasing, mechanically stable, tissue-free hydrogel KPro with site-specific surface functionality nearly mimicking the cornea's functionality. A further pre-clinical investigation is necessary to advance this functional novel KPro to reality, especially the tissue integration aspect. Differentially surface functionalized semi-bioresorbable keratoprosthesis. image