Construction of the electro-bioactive coating on the dental implant surface

Objectives:Electrically conductive polypyrrole (PPy) has demonstrated substantial potential for biomedical application because it may be used in contact with biological components to apply an electrical stimulation and electrochemically grown directly onto metallic substrates of any shape and dimension. The objectives of this study were to trap bioactive molecule into PPy coating on titanium and complete the electro-bioactive coating on Titanium. Methods: PPy coatings have been successfully electrosynthesized on the Ti-substrates by constant current method in aqueous media. Then the PPy-coated titanium substrates were synthesized containing the PPy and rhBMP-2. The chemical composition and configuration of the PPy coating were studied by FTIR and XPS to demonstrate the rhBMP-2 that had been trapped into PPy structure. 125I radiolabeling technique was used to measure the amount of rhBMP-2 which was doped in or released from the PPy-coated titanium substrates. The MTT assay was adoped to ensure that the structure and function integrity of doped or elicited protein. Results: rhBMP-2 could be incorporated into PPy coating and showed that the coating could be reduced electrically and elicited from the PPy coating, subsequently promote osteoblastic cells growth. The PPy-coated titanium substrates with the biomolecule doped in are also electroconductive and bioactive. Conclusion:This research explored the possibility and the biological effects of construction of a electro-bioactive coating on the dental implant surface using electrically conductive polymer-polypyrrole(PPy). This paradigm proved to be very powerful in combining the principles of surface engineering with electromagnetic therapy in promoting dental implant osseointegration.