Preparation and Gel Properties of Poly[hydroxyethylmethacrylate-co-poly(ethylene glycol) methacrylate] Copolymeric Hydrogels by Photopolymerization

Copolymeric hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and poly(ethylene glycol) methacrylate (PEGMA) and isopropanol as a diluent were prepared by photopolymerization. The swelling kinetics, mechanical properties, drug release behaviors, and the interaction between various drugs and the present copolymeric gels were investigated in this study. The results showed that the addition of PEGMA could effectively increase the equilibrium water content and the diffusion coefficient and penetration velocity of water though the gels. Although Young's modulus increased with the increase of PEGMA content, the resulting gels had smaller elongation and more brittle characteristics. The drug release behavior was strongly dependent on the interaction between the present copolymeric gels and drugs such as caffeine, crystal violet (CV), phenol red, and vitamin B₁₂.