Apatite/polypyrrole composite prepared by a biomimetic process

Apatite coatings were fabricated on polypyrrole (PPy) substrate by a biomimetic process using simulated body fluid (SBF). PPy was chemically synthesized with heparin sodium salt and toluene-4-sulfonic acid (P-TSA) as dopants. But apatite coatings were not induced when PPy was prepared without dopants, which suggests that heparin sodium salt and P-TSA play an important role in the formation of the apatite coatings. The possible mechanism responsible for the formation of apatite coatings was discussed. It is expected that this apatite/polypyrrole composite can be used as bioactive coatings on metal implants and tissue engineering scaffolds.