Abstract
Purpose: :
Xeno-/allo-derived material in cultivated epithelial sheets is used in the treatment of limbal stem cell deficiency. Enhancing the amount of progenitor cells is a critical issue. The aim of this study is to find a method for culturing human epithelium on surface modified contact lenses, which can facilitate expansion and enhance transfer of autologous limbal epithelial cells.
Methods: :
A range of plasma polymer coating contact lens were developed and X-ray photoelectron spectroscopy (XPS) was used to analyze the chemical composition of the plasma polymer deposited layer. Human research- consented corneas were supplied by the Lions Eye Bank of Victoria. Cell attachment and viability on a range of plasma polymer surfaces was assessed. Morphological analysis and confocal microscopy were also performed. Immunocytochemical staining was performed to evaluate the expression of two corneal stem cell markers. Rt-PCR array (RT2-PCR-A) for 84 genes related to the identification, growth, maintenance, and differentiation of stem cells (SCs) was performed. The expression of SC specific markers, SC differentiation markers and Signaling pathways important for SC maintenance was studied.
Results: :
Limbal epithelial cells (LEC) do not attach to 100%1,7-octadiene (OCT) coated contact lenses, while acrylic acid (AA) coated contact lenses provided an ideal substratum for adhesion, migration and rapid expansion of LEC from explants. A continuous monolayer of polygonal epithelial cells was seen after 10 days in culture as shown by phase contrast microscopy, fluorescent microscopy and H&E staining. Immunofluorescent staining showed that there was different expression pattern in cells radiating out from each explants. ABCG2 antibody stained most cells outgrown from the explants, while nuclear proteinp63was only expressed in the cells of the front edge. Cell growth from limbal explants cultured on 100% AA contact lenses was faster than 75:25 and 50:50 AA: Oct contact lenses. RT2-PCR-A results indicated an increased expression in 11 genes, in cells from the 100% AA contact lenses compared to cells from 50:50 AA : Oct contact lenses.
Conclusions: :
A method for culturing human ocular surface epithelium on contact lenses has been developed to facilitate expansion and transfer of limbal epithelial cells thereby avoiding the risks associated with transplanting allogeneic tissue. A surface treatment by plasma polymerization can affect cells growth and progenitor cells maintenance.
Keywords: cornea: epithelium • cornea: basic science • contact lens