Development of semicrystalline poly(vinyl alcohol) hydrogels for biomedical applications.

Swollen crosslinked poly(vinyl alcohol) (PVA) networks were developed and tested as potential biomaterials. They were prepared by electron-beam irradiation of aqueous PVA solutions at various temperatures and doses of irradiation. These materials were characterized by low mechanical properties and especially by low elongation at break and ultimate tensile strength. Reinforcement was achieved by a two-stage dehydration-annealing process, introducing crystallites in the polymeric network. Improved mechanical properties were achieved due to the presence of this crystalline PVA phase. Due to their structure, these hydrogels are proposed to be used as biomembranes for selective transport of macromolecules and as biomaterials for synthetic articular cartilage applications. Surface heparinization was accomplished by reacting heparin to the hydroxyl groups of the PVA surface, through covalent acetal bridges.