MICROENVIRONMENTAL REGULATION OF CORNEAL LIMBAL EPITHELIAL CELLS CULTURED ON DENUDED AMNIOTIC MEMBRANE: EMPHASIS IN SUPRAMOLECULAR ORGANIZATION OF MAJOR EXTRACELLULAR BIOPOLYMERS

Abstract

Evolution of risk/benefit that accompanies the bioengineered tissues used for reconstruction of ocular surfaces with limbal stem cell deficiency depends on new ideas and methodological approaches for studying the microenvironmental regulation of corneal limbal epithelial progenitor cells and developing a new generation of substrates/membranes susceptible for expansion of them. Clearly, emphasis have been given to the role of biochemical cues (involving soluble molecules) in regulating corneal limbal epithelium cultured on different substrates, especially denuded amniotic membrane (routinely used in ophthalmology reference centers). In contrast, epithelium regulation by biophysical cues related to supramolecular organization of extracellular biopolymers into the limbus (in the case of explant culture system) and the cell expansion/attachment substrate has been poorly studied. It is known that supraorganization (molecular order) create cell-matrix interaction sites that are able for activating/deactivating mechanotransduction pathways and for enhancing/neutralizing the action of growth and survival factors. At least five structural properties of denuded amniotic membrane, which can contribute to phenotypic modulation and polarization of cultured cells, are associated with extracellular matrix supraorganization: geometry, topography, spatial orientation, stiffness/elasticity, and force. With advances in nanotechnology, material science and supramolecular chemistry, the perspective of exploring a supraorganization (reflecting nanoscale applications) for subsequently create synthetic biomimetics membranes become true. Several recent studies concluded that the future of regenerative medicine is nano and supra. Thus, the main goal of this research is to evaluate the supramolecular organization of the major biopolymers (ie. collagens and proteoglycans) of the extracellular matrix from denuded amniotic membrane combined with limbal explants in therapeutic cell culture systems for corneal surface reconstruction. The optical phenomena resulting from the interaction of extracellular matrix supraorganization with electromagnetic radiation will form the basis of our analyses.