[Regeneration of corneal epithelium using keratin modified chitosan membranes]

The cornea is a transparent front layer of the eye. It functions like a window that controls and focuses the light entering into the eye. The cornea contributes to 65-75% of the eye's total focusing power and it acts as a physical barrier against pathogenic microorganisms, dirt and other noxious physical factors. The corneal tissue is arranged in five basic layers. The outermost layer (epithelium) is made up of highly regenerative cells that allow for quick healing of superficial injuries. Eye infections, diseases, or mechanical injury can harm corneal epithelium and cause blindness. Under certain circumstances, to prevent that, it is recommended to perform complete corneal transplantation. However, due to lack of sufficient number of donors, researchers are searching for alternative solutions.. Regeneration of epidermal tissue can restore and ensure normal functioning of cornea. For that purpose proper grafts are needed. The goal of current research was to develop the material for scaffold preparation providing optimal conditions for the epithelium cornea cell culturing and to determine its chemical, physical, and biological properties. The scaffolds, which could be applied in ophthalmology should fulfill a lot of requirements, among them such as biocompatibility, biodegradability, restorability, non-toxicity. They should also have adequate mechanical strength, flexibility and porosity. The aim of this work was to synthesize and to determine the properties of polymeric material for ophthalmic surgery applications. A hydrogel scaffold in the form of membrane was obtained from chitosan - natural, biocompatible, biologically inert, stable in the natural environmental and antibacterial polysaccharide derived from chitin. Biodegradable chitosan films containing keratin were crosslinked with genipin - a naturally occurring and nontoxic agent. In this study we present physicochemical characterization of the scaffolds. Porosity, contact angle and swelling ratio (at different pH) were determined. The optical microscope technique was used to visualize the microstructure of the scaffolds. Atomic force microscopy (AFM) measurements revealed the topography of the surfaces of membranes. The biological tests have shown that epithelial cells seeded on the membranes proliferated efficiently.