Alternating potentials assisted electrochemical deposition of mineralized collagen coatings

Mineralized collagen coatings were synthesized by electrochemical deposition with alternating negative and positive potentials. The obtained coatings demonstrated a multi-layer structure alternating consisting of weakly and highly mineralized collagen layers and the proportion of each layer could be controlled by adjusting the deposition time. The coatings deposited using alternating potentials assisted electrochemical deposition (AP-ECD) showed significantly enhanced osteoblasts proliferation, and rhBMP-2 loading capability compared to those of the coatings deposited using constant potential electrochemical deposition (CP-ECD). The enhanced cytocompatibility and rhBMP-2 loading capability of the coatings might be attributed to their high proportion of weakly mineralized collagen layer. Furthermore, the deposition mechanism for alternating potentials is proposed as that positive potential induces deposition of negatively charged collagen fibrils to form a weakly mineralized collagen layer. Our results suggest that the present deposition method could be a promising approach to engineer mineralized collagen coating with better biological performances.