Polypyrrole/graphene oxide composite coating on Ti implants: a promising material for biomedical applications

Advanced materials can be developed by the combination of synthetic polymer and nanomaterial for biomedical application. Polypyrrole/graphene oxide (PPy/GO) composite coating on Ti metal was developed through electropolymerization of pyrrole by varying the amount of GO in aqueous oxalic acid solution. The influence of GO in the PPy matrix was confirmed by scanning electron microscopy studies. Structural interactions between PPy and GO in the composite coating were studied using ATR-FTIR, solid C-13 NMR and Raman spectroscopy. The higher surface roughness and the lower wettability of the composite-coated Ti favor biocompatibility. The increase in adhesion strength of the composite coating was analyzed by the cross-hatch adhesion test. Potentiodynamic polarization studies showed a higher polarization resistance (R-p) and lower corrosion rates for composite coatings. Dynamic electrochemical impedance spectroscopy studies confirmed the PPy/GO composite coating exhibited a higher impedance from - 0.55 to 1.25 V in SBF solution. Bode impedance and Bode phase angle results revealed a higher resistance for PPy/GO composite-coated Ti. Immersion studies of PPy/GO composite coating in SBF solution revealed the growth of dense hydroxyapatite (Hap.) over Ti metal. Further, in vitro cell culture studies were carried out by MG-63 cells to assess the biocompatibility of PPy/GO composite coating on the substrate. Improved corrosion protection and biocompatibility behavior of PPy/GO composite-coated Ti suggests the potential candidate for biomedical applications.