Enhancement of conductivity, mechanical and biological properties of polyaniline-poly(N-vinylpyrrolidone) cryogels by phytic acid

Polyaniline-based cryogels were prepared by oxidative cryopolymerization in the presence of various concentrations of poly(N-vinylpyrrolidone) and phytic acid used as a polymer support and a dopant, respectively. Mechanical strength and handling stability of the resulting macroporous materials (pore size up to 70 μm) were significantly improved by the addition of poly(N-vinylpyrrolidone) into the polymerization system compared to the cryogels crosslinked only by phytic acid. Increase of poly(N-vinylpyrrolidone) concentration in the reaction medium above 5 wt%, while not noticeably changing mechanical properties, was found to lead to a decrease of conductivity and specific surface area. Introduction of optimal amount of phytic acid (0.2 M) as an additional codopant, in opposite, allowed enhancement of the material conductivity and specific surface area as well as increase of their tensile modulus. Polyaniline-poly(N-vinylpyrrolidone) cryogels containing phytic acid also showed better cytocompatibility due to lower cytotoxicity and improved cell adhesion and proliferation.