Hemocompatibility, swelling and thermal properties of hydrogels based on 2-hydroxyethyl acrylate, itaconic acid and poly(ethylene glycol) dimethacrylate

Two series of novel hydrogels, based on 2-hydroxyethyl acrylate (HEA), itaconic acid (IA), and two poly(ethylene glycol) dimethacrylates (PEGDMA), of different ethylene glycol chain lengths, were prepared by free radical crosslinking copolymerization. The influence of different ethylene glycol chain lengths and concentration in P(HEA/IA/PEGDMA) hydrogels on biocompatibility, swelling and thermal properties was investigated. All samples in contact with blood showed a mean hemolysis value < 1.0 % in the direct contact assay, and even < 0.5 % in the indirect contact assay, for in vitro testing conditions. Swelling studies, conducted in a physiological pH and temperature range, showed pH sensitivity and relatively small changes of equilibrium swelling with temperature, which varied with PEGDMA molecular weight. The glass transition temperatures (T (g)) of P(HEA/IA/PEGDMA) networks were in the range 28.1-36.9 A degrees C, respectively, and also dependent on copolymer composition. Due to good biocompatibility, favorable swelling, and thermal properties these hydrogels show good potential for biomedical uses.