Lens Epithelial Cell Response to Polymer Substrates
Loading...
Date
2023-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
The Ohio State University
Abstract
Cataracts are the largest cause of blindness worldwide along with causing cases of other visual impairments. This disease adversely affects low-income regions leading to a greater number of people affected in those regions. The medical treatment for cataracts is a surgery in which the cloudy lens is removed, and an intraocular lens is implanted in the lens capsule. There is a post-operative complication that results in a secondary loss of vision. Remnant lens cells cause this complication with abnormal behavior including increased proliferation, migration across the lens, and differentiation, or epithelial to mesenchymal transition (EMT). A laser treatment has been developed to clear the cells impacting vision; however, no solution has been developed to avoid the patient suffering again through a decreased quality of vision. There have been recent studies that show changing IOL properties can deter the cellular processes that lead to PCO. This project focuses on options for a new IOL polymer composition that may have the ability to prevent PCO. To accomplish the goals of this project various polymers were created including PMMA, 1:2 TRIS-HEMA, 2:1 TRIS-HEMA, Poly-HEMA, and Poly-TRIS. Primary lens epithelial cells (LECs) were obtained from porcine eyes and immortalized human LECs were used as well. Atomic Force Microscopy (AFM) was done to find the stiffness of the polymer samples. The samples were seeded with the primary cells, and a Cell-Titer Glo Assay was performed to assess cell viability. Calcein AM staining was used to obtain pictures of cell morphology when seeded upon the different polymer samples. A migration assay with half polymer solution surface and half tissue culture treated surface was conducted to investigate preferential attachment of cells. Information from the assay was obtained with the use of a LIVE Calcein AM treatment to label the cells and a microscope to take pictures. The stiffnesses of the polymers ranged from high to low as following: Poly-TRIS, 2:1 TRIS-HEMA, 1:2 TRIS-HEMA, and PMMA. Considering the results of the Cell-Titer Glo assay, there was a significant change in cell viability between the Laminin control treatment and 2:1 TRIS-HEMA, 1:2 TRIS-HEMA, and PMMA which was likely caused by an adherence issue with the Laminin coating on glass coverslips. The higher stiffness polymers showed greater cell growth. The Calcein AM staining found a statistically significant lower circularity in Poly-TRIS and 2:1 TRIS-HEMA when compared to the Laminin control. Given that the aspect ratio values did not show a significant difference when compared to the Laminin control, conclusions can't be drawn about the ability of any of the polymer compositions to deter leader cells which are an indication of EMT. There was a qualitative difference observed between the proliferation of the HLECs in the Laminin control treatment half well-plate compared to the Poly-HEMA, Poly-TRIS, and 2:1 TRIS-HEMA covered halves. Poly-TRIS and 2:1 TRIS-HEMA showed the lowest stiffness which may contribute to their ability to discourage cell attachment in the migration assay. Overall, Poly-HEMA and Poly-TRIS showed consistent indicators aligned with PCO deterrence including neither hyperproliferation nor preferential attachment.
Description
Keywords
Posterior Capsular Opacification, Intraocular Lens, Epithelial to Mesenchymal Transition, Polymer Characteristics, Lens Epithelial Cells, Cataract Surgery