Abstract
Abstract: :
Purpose: Previously, we reported on the cellular adhesion strength of primary rabbit corneal epithelial cells to specifically surface–modified biomaterials using jet impingement. In this study, we further characterized the jet impinged surfaces to determine the physical extent to which the disrupted cells were removed from the surfaces. Methods: Primary rabbit corneal epithelial cells were isolated and seeded onto four different hydrogel materials with proteins and/or peptides tethered to their surfaces: 1) laminin tethered, 2) fibronectin tethered, 3) fibronectin adhesion peptide (FAP) tethered and 4) 50% laminin and 50% fibronectin tethered. Glass was used for the control surface. Hydrogels with confluent cell layers were subjected to the jet impingement technique described by Bundy et al. Immediately after impingement, the remaining cells were fixed and stained sequentially with bisbenzimide trihydrochloride for DNA, and phalloidin for F–actin. Surfaces were then imaged under white, UV, and fluorescent light to determine the extent to which cells were removed from the impingement site. Results: Of the materials tested, tethered laminin, FAP, and 50/50 laminin/fibronectin surfaces had significantly more cells or cellular adhesion remnants remaining within the lesion area than other surfaces including glass. Conclusions:Earlier work by our laboratory indicated that materials tethered with laminin, FAP, or 50/50 laminin/fibronectin allowed corneal epithelial cells to bind to their surfaces with a strength greater than that by which those same cells bind to glass. In this study, a closer look at the lesion surface indicates that the same materials that had previously shown the highest strength of cellular attachment had the highest percentage of cells or adhesion remnants on their surfaces. These results indicate that certain tethered–protein hydrogel surfaces allow corneal epithelial cells to bind so tightly that the cells are often fractured during impingement rather than completely removed from the surface.
Keywords: cornea: epithelium • cell adhesions/cell junctions • keratoprostheses