Protein adsorption resistance and oxygen permeability of chemically crosslinked phospholipid polymer hydrogel for ophtnalmologie biomaterials

The bioniimetic structure of a polymer hydrogel bearing phosphorylcholine groups was obtained from 2-methacryloyloxyethylphosphoryicholline (MFC) and a novel crossllnker, 2-(methacryloyloxy)ethyl-N-(2-inethacryIoyloxy)ethyl] phosphorylcholine (MMPC), to prepare biocompatible ocular materials. MMPC is a dimethacrylate with phosphorylchoine-analogous linkage. Previous reports clarified that the affinity of MMPC to MFC enables the water contents and mechanical properties of the poIy(MPC) hydrogels to be varied without disturbing the bulk phases. In this study, we examined the protein adsorption resistance, water wettability, oxygen permeability, and electrolyte permeability of the mechanically enhanced poly(MPC) hydrogel crosslinked with MMPC. The amount of protein adsorbed on this hydrogel was 0.9μg/cm², which accounted for 30% of Omaflleon A and 3% of Etafilcon A. Water contact angle experiments revealed the high wettability of the poly(MPC) hydrogels. The oxygen permeability and NaCI diffusion constant of the poly(MPC) hydrogels were 64 barrer and 48 × 10^-6 cm^2/s, respectively. This high permeability resulted from the high water content, similar to the case of the human cornea. These results suggested that poly(MPC) hydrogels have good potential for use In ophthalmologic biomaterials.