RESUMO
The aim of this paper was to present a parallel investigation of the poly(dopamine) (DP) and nitrodopamine (NDP) structures deposited on titanium surface (Ti) and titanium oxide nanotubes (NT-TiO2/Ti) and to highlight their advantages and drawbacks to serve as an intermediary layer for bone regeneration applications. This study outlines some hypotheses regarding the manner in which these compounds are able to form a stable film that could serve as bioadhesive. The paper is also a study of structuring and evolution of film architecture for two coatings, polydopamine and nitrodopamine in terms of surface structure, stability, wettability, morphology, adhesion and ability to protect the titanium surface. All investigations are based on the data provided by surface characterization techniques: SEM, RAMAN, XRD, XPS, wettability and flexural strength. The impact of polydopamine and nitrodopamine coatings on the biocompatibility of titanium nanotubes was investigated in vitro. Cell morphology, viability, proliferation and pre-osteoblast differentiation were examined in detail. It was highlighted that both DP and NDP functionalized TiO2 nanotubes display good cell response in terms of cell spreading, formation of focal adhesions, cell viability and proliferation, suggesting their suitability for applications in bone regeneration field. However, NDP coated TiO2 nanotubes demonstrated an enhanced osteogenic potential compared to DP coated substrates.