ESTUDO DA BIOATIVIDADE DE SUPERFÍCIES TEXTURIZADAS DE TITÂNIO: FORMAÇÃO DO FILME CONDICIONANTE E ADESÃO CELULAR

Abstract

Titanium is considered an ideal material for bone implant manufacture. However, the biomaterial interaction with the organism can lead to deteriorating reactions, related to failure, debris, and to rejection. In this context, surface modification presents itself as a good strategy for implant properties modulation and enhancement of corrosion protection, while mediating osseointegration. In face of this, this study aimed to investigate the effect of titanium surface modification on physical-chemistry (corrosion and protein adsorption) and biological (cell adhesion and hemolysis) aspects of interaction. Bioactive surfaces were obtained by mechanical polishing, acid-etched, and anodization of Ticp. Texturized samples were characterized by FE and FIB-SEM, XDR, FTIR, EDX, WCA, profilometry, electrochemical behavior, protein adsorption, hemolysis, and fibroblast adhesion. Results show that morphological and physicochemical characteristics of the surface can be tailored for different application purposes. The highest corrosion resistance and apatite deposition were presented by anodic samples. Albumin adsorption was related to surface roughness and wettability, following the Langmuir model isotherm (Type I), except for galvanostatic samples (Type III). All kinetic adsorption was modeled by a pseudo-first-order model, and the rate-limiting step relied on albumin diffusion to the pores. All surfaces meet the hemocompatibility requirements for their use as biomaterial (hemolysis index < 2%). Cellular behavior was also found to be dependent on surface macroroughness (Sa), and so, the corrosion presented by the surface. The threshold for viability, adhesion, and proliferation behavior of fibroblasts was Sa ≈1 µm. Except for the samples obtained by acid etching treatment, all surfaces meet this requirement. By combining the results, anodic samples present optimized surface conditions, which can promote better body-fluid contact and better cell interaction, contributing to long-term stability.