Electrodeposition of polypyrrole coatings on anodized titanium surfaces for dental implants application

Abstract

Conductive polymers have been pointed as a promising coating strategy for biomaterials. Polypyrole (PPy) is a conductive polymer that present adequate biological and anticorrosive properties when deposited onto titanium (Ti) surfaces. However, PPy coatings have limitations such as low adhesion to metals and poor mechanical resistance. Therefore, this study aims to develop a biocompatible coating with plasma electrolytic oxidation (PEO) (anodization) and the subsequent deposition of PPy film on the Ti surfaces to investigate the effect of anodization on the adhesiveness, physical-chemical, mechanical, biological and corrosion resistance properties of PPy. Thus, commercially pure titanium (cpTi) discs will be used with different treatments: (1) machined; (2) anodized; (3) machined and PPy-coated; (4) anodized and PPy-coated. Discs surfaces will be characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Vickers microhardness, surface free energy, profilometry and 3D confocal laser scanning microscopy (CLSM). The friction coefficient of surfaces will be evaluated in a tribological system and the morphology of the wear scars will be investigated by SEM. Electrochemical tests will be conducted with body fluid solution (SBF) (pH 7.4). The albumin protein interaction with the surfaces will be measured by the bicinchoninic acid method. For the microbiological assay (microcosm model), the adhesion (2 h) and biofilm (24 h) formation onto cpTi surfaces will be evaluated by colony forming units (CFU/mL), the biofilm structure will be analyzed by SEM and the live and dead cells will be evaluated by CLSM. The cytotoxicity of surfaces for MC3T3-E1 pre-osteoblastic cells will be investigated using the MTT assay. Furthermore, SEM and CLSM will be used to analyze the morphology of cells onto the surfaces. Quantitative data will be submitted to the appropriate statistical analysis with significance level of 5%. The number of samples for each assay will be determined after the pilot study. (AU)