Intraocular Lenses with Functionalized Surfaces by Biomolecules in Relation with Lens Epithelial Cell Adhesion

A cataract is pathology opacity of the lens or capsule of the eye, causing impairment of vision or even blindness. In 1998, it was estimated that worldwide 19.4 million people were bilaterally blind from age-related cataract. Surgery, with lens extraction and intraocular lens implantation, is still the only currently available treatment. More than 1.3 million cataract operations were performed in the USA in 1998 at a cost of $3.5 billion.
The most common complication after implantation of intraocular lenses (IOLs) is the posterior capsular opacification (PCO) or secondary cataract. This is the result of lens epithelial cells (LECs) proliferation and their transition to mesenchymal cells. In 1997, a Sandwich theory was proposed to elucidate the developmental process of PCO. According to this model, an IOL with higher affinity to LECs will induce a less PCO.
In our research, the pHEMA (Poly(2-hydroxyethyl methacrylate)) based acrylic hydrophilic polymer is subjected to the surface modification by conjugating with the bioactive peptides. The RGD sequence, known for its excellent biocompatibility, is designed to stimulate the biointegration between the LECs and the polymer implant. Our research program will focus on the evaluation of the physical, mechanical and biological properties of the lens before and after peptide grafting. These diverse tests include contact angle measurements, Atomic Force Microscopy (AFM), x-ray photoelectron spectroscopy (XPS), FTIR/ATR, Scanning Electron Microscopy (SEM), and the MTS cytotoxicity assay.