The effect of polar copolymers in protein absorption on contact lenses on 2-Hydroxyethyl methacrylate(HEMA)

For the purpose of increasing the permeability to oxygen and equilibrium water content in contact lenses, polar copolymers with nonionic monomers such as 2-hydroxyethle methacrylate(HEMA) Is used. By adding the polar monomers to (HEMA), the permeability to oxygen and equilibrium with water content is increased and also the absorption of proteins on lens surface is changed. In this research, the acrylic acid (AA) was added to (HEMA) monomers in versatile percents and was applied as surface. Three types of proteins including: Albumin, Lactoferrin and Lysozyme and UV-VIS spectroscopy is applied at 280 nm for the monitoring of absorption on these surfaces. The amount of absorption of these proteins in different pH values(4.8,6.8, and 8.8) is evaluated and the effect of pH on the protein absorption is studied. By adding the polar monomer to the (HEMA) surface the absorption of protein was changed and the amount of absorption depends to pH.