Knowledge Bank

The cornea is the outermost layer of the eye, which makes it more susceptible to injury. In 2015 approximately 604,000 individuals in the US underwent some form of refractive laser surgery and many of those individuals developed corneal flaps created by the surgery that do not fully heal and do not completely reattach to the cornea even years after surgery (Riau et al., 2011). Additionally, 27% of all patient visits for ocular injuries are the result of corneal abrasions and lacerations (Ashby, Garrett, & Wilcox, 2014). Instances of improper corneal wound healing indicate a clinical need for a therapeutic method to improve corneal wound healing without scarring. Throughout the phases of corneal wound healing, fibroblasts and myofibroblasts proliferate and begin to form an extracellular matrix. When these fibroblasts and myofibroblasts are over expressed abnormal healing occurs resulting in opacity that frequently leads to the requirement of a corneal transplant. Many researchers have studied the mechanical and biological properties of healthy corneas while others have observed epithelial cell migration on therapeutic contact lenses after surgery. However, despite this extensive research there is a scientific gap in the understanding of how the chemical and mechanical properties of materials influence corneal wound healing. The purpose of this study aimed to identify the optimal surface free energy that promotes preferential attachment of corneal epithelial cells to ultimately design better materials, such as therapeutic bandage lenses, for use in corneal repair. Amphiphilic polymers with different ratios of 2-hydroxyethyl methacrylate (HEMA) and 3-methacryloxypropyl tris(trimethylsiloxy)silane (TRIS) were synthesized via free radical copolymerization to produce amphiphilic copolymers. Surface free energies were determined utilizing a goniometer to take contact angle measurements. Surface chemistry was further analyzed using FTIR. Seeding of NIH 3T3 fibroblast cells onto the polymer films was done to determine cell attachment and viability differences between the polymers. Initial results indicate highest cellular viability on pure TRIS polymer with varying results for amphiphilic polymers. FTIR results indicated successful polymerization. Surface free energy testing produced inconclusive results with further testing needed to optimize film casting and goniometer methodology. Further experiments must be run to conclusively determine surface free energy of the amphiphilic polymers along with cell viability on the various polymers.