Synthesis of pH-sensitive PVP/CM-chitosan hydrogels with improved surface property by irradiation

In order to develop a nontoxicity, biocompatibility, pH-sensitive hydrogel system with potential ability to immobilize and absorb proteins, the hydrogel membranes of poly(N-vinylpyrrolidone) (PVP) and carboxymethylated chitosan (CM-chitosan) blend were prepared with electron beam (EB) irradiation at room temperature. The FTIR spectroscopic, mechanical property, swelling behavior, and surface property of the hydrogel membrane were measured. The capacity of these gel membranes to adsorb bovine serum albumin (BSA) was investigated with varying content of CM-chitosan by static adsorption experiment at pH 7.4. The mechanical and swelling properties were improved obviously after adding CM-chitosan into PVP hydrogels. The changes of contact angles of water, glycerin and octane drops on the blend membranes surface with increasing CM-chitosan content indicated that the CM-chitosan molecules were more hydrophilic than PVP molecules, and cause a larger polar component of surface free energy. The incorporation of CM-chitosan introduced the protein adsorptive property into blend system. From these preliminary evaluations, it is possible to conclude that these materials have potential for applications in the biomedical field.