Preparation and characterization of spongy cryogels of poly(vinyl alcohol)-casein system: water sorption and blood compatibility study

Polyvinyl alcohol (PVA) and casein are biocompatible and biodegradable macromolecules, which have been widely applied in biomedical fields. In this paper, novel physically crosslinked hydrogels composed of PVA and casein were prepared by repeated freezing-thawing treatment of aqueous solutions of PVA and casein and characterized by IR, differential scanning calorimetry and scanning electron microscopy techniques. The prepared so-called 'cryogels' were evaluated for their water uptake, and the influences of various factors, such as their chemical architecture and the pH and temperature of the swelling bath, were investigated in terms of water sorption. The effect of salt and various simulated biological fluids on the swelling of cryogels was investigated. The in vitro biocompatibility of the prepared cryogels was also judged by methods such as protein (bovine serum albumin) adsorption, blood clot formation and percentage haemolysis measurements. (c) 2005 Society of Chemical Industry.