Purchase this article with an account.
Waleed Abdel-Naby, Aihong Liu, Nicholas Wey, Mark I Rosenblatt; Silk fibroin substrates support corneal epithelial cellular adhesion under shear stress. Invest. Ophthalmol. Vis. Sci. 2014;55(13):4633.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Thin silk films support the growth of human corneal epithelial cells. In this study, we aim to characterize the ability of silk fibroin to support cellular adhesion under physiologically relevant shear stress.
To study the biological surface adhesion characteristics of silk fibroin films, we performed a quantitative analysis of Human Corneal Limbal Epithelial (HCLE) cell adhesion on planar silk surfaces. We developed and applied a biologically relevant model system that allows us to evaluate the strength of epithelial adhesion on silk films under various levels of shear stress. Isolated HCLE cells were seeded and grown on silk fibroin substrates of approximately 30um in thickness. A flow chamber cell was used to subject the cells to well defined step increases in shear stress (10-40Pa). Cells were sequentially imaged during the course of the assay on a Zeiss Observer Z1 microscope (Carl Zeiss, AG) with 10x objective and phase contrast filter. Images of cells were taken before and after each step increase in shear force using an AxioCam single-channel camera and AxioVision software (Carl, Zeiss). The total number of adherent cells was counted at each interval to evaluate cell detachment as a function of wall shear stress. Cell alignment was also evaluated to characterize the dynamics of cell deformation in response to applied shear force.
Analysis of our results show a significant decrease (P<0.05) in the number of attached cells grown on standard tissue culture plastic compared to cells grown on silk fibroin, in response to applied shear forces. The most dramatic difference observed in cell attachment was after 30Pa of applied shear force. Results also indicate that cells grown on tissue culture plastic showed a higher degree of deformation and elongation in response to the onset of flow, when compared to cells grown on silk fibroin.
Our data showed that silk fibroin substrates support stronger epithelial adhesion compared to standard tissue culture plastic surfaces Cell deformation and elongation was observed to be less in cells grown on silk fibroin indicating that the cells were more resilient to the applied fluid shear. These findings add to our understanding of corneal epithelial cell biology as well as allow for smarter design and application of silk film devices for ocular surface reconstruction.
This PDF is available to Subscribers Only