Molecularly Engineered p(HEMA)-based Hydrogels Possessing Poly(Ethylene Glycol) and Phosphorylcholine for Implant Biocompatibility

Hydrogels based on 2-hydroxyethyl methacrylate (HEMA) crosslinked with tetraethylene glycol (TEGDA) and molecularly engineered using two methacrylate-based monomers, poly (ethylene glycol) (200) monomethacrylate (PEGMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) in the range of 0.0 - 0.5 mol % and 0-10 mol % respectively were investigated. Hydration studies demonstrated up to a 93.8% increase in the hydration with an increase in the MPC content. Data obtained from the measurement of the fluorescence intensity of FITC-dye tagged protein adsorbed onto various hydrogel substrates when exposed to solutions of different protein concentration solutions at 25degC were modeled to the Langmuir isotherm. Variables K_d and Q_m confirmed the reduction in the adsorption of protein onto hydrogels with the increase in the MPC concentration and with extensive hydration of the hydrogels, 5 days. Cell viability studies using human aortic muscle endothelial cells exhibited greater than 80% viability with all the hydrogel formulations studied. Cell retention in the hydrogel matrix was investigated by staining cells that remained in the hydrogel matrix following trypsinization, with a fluorescent dye DAPI. It was observed, using fluorescence microscopy, that the higher the MPC content in the hydrogel the greater the cell retention capacity of the hydrogel