Purchase this article with an account.
N. C. Tanti, L. Jones, M. Gorbet; Effect of Multipurpose Solutions Released From Silicone Hydrogel Lenses on Corneal Epithelial Cell Adhesion Phenotype and Apoptotic Pathways in vitro. Invest. Ophthalmol. Vis. Sci. 2009;50(13):4614.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Cytotoxicity of Multi-Purpose Solutions (MPS) is commonly tested on cells using diluted MPS or extracts from MPS soaked contact lenses (CL). There is evidence that lens type will affect uptake and release of compounds contained in MPS. To assess the cytotoxicity of agents contained in MPS that would be released by CL, a model whereby the CL was directly set onto a confluent monolayer of corneal cells, was devised. Cell viability and adhesion phenotype were studied.
Immortalized human corneal epithelial cells (HCEC) were cultured in a keratinocyte serum-free medium supplemented with bovine pituitary extract, epidermal growth factor and pen-strep. A monolayer of HCEC was seeded in a 24-well tissue culture plate. MPS-soaked CLs were placed on top of the adherent cells. After the designated time, CLs were removed. Cells were assayed for cellular viability using the MTT assay or for integrin expression and caspase activation by flow cytometry.
When compared to cells without a CL or incubated with a CL soaked in PBS (controls), more than 20% reduction in cell viability was observed at 8 hours with CLs soaked in OFX (CL-OFX) and ReNu (CL-ReNu). After 24 hours contact with CL-OFX, viability was further reduced to 50% of control. Viability of cells exposed to CL-ReNu did not change significantly compared to 8 hours. Significant decreases in the expression of β1, β4 and 3 were observed at 8 and 24 hours with CL-OFX and CL-ReNu: at 24 hrs, a 30 to 40% reduction in expression of both β1 and 3, two of the integrins responsible for the maintenance of cell-cell junctions and stability of hemidesmosomes, was recorded. Caspase activation was evaluated at 12 hours and CL-OFX led to an increase in the number of cells staining positive.
The results indicate that exposure to CL soaked in MPS in vitro not only induces cell death, but also has an adverse effect on adhesion phenotype, suggesting a compromised epithelial structure. The in vitro model was also sensitive to the chemistry of the material (i.e the release profile of MPS) and was able to identify difference between two silicone hydrogels with different surface treatments. Our preliminary results with caspase activation suggest that ReNu and OFX induced corneal epithelial cell death in vitro using different pathways. Further investigation is needed to better understand lens solution incompatibilities with HCEC.
This PDF is available to Subscribers Only