Fabrication and characterization of collagen-heparin-polypyrrole composite conductive film for neural scaffold.

In this work, a conductive film consisted of polypyrrole-heparin-collagen (PHC film) was fabricated as a potential neural scaffold. Heparin was initially modified with pyrrole, which was further polymerized with pyrrole monomer under the catalysis of ferric trichloride. Then collagen was added and crosslinked through amide bond, as well as physical interaction with pyrrole through hydrogen bond. In this system, heparin and collagen contributed to improving the biocompatibility, because they were the major component of the extracellular matrix. Additionally, heparin was verified to promote nerve cells growth. The physicochemical properties of PHC film were verified, including structure, morphological analysis, degradation, swelling, electrical properties and so on. Combined with the promotion results of pheochromocytoma cells growing, this PHC film is expected to be a promising alternative for nerve regeneration.