Design of advanced biomedical Ti-based alloy with bioactive and osseointegrative capabilities

Full text: Titanium (Ti) is used as dental and orthopedic implants due its good biocompatibility and favorable mechanical properties. Alloying elements are used to form solid solution with friendly mechanical properties [1]. In addition, surface modifications are applied on Ti surfaces, enhancing the interaction between the metal and the biological host and favoring osseointegration process. Micro-arc oxidation (MAO) is a surface modification technique which allows the growth of a microporous oxide layer and the incorporation of specific ions from the electrolyte, such as Ca, P and Mg, which are the main elements that constitute the human bone [2]. The aim of this study is to characterize the oxide layer of Ti-¹⁵Zr-¹⁵Mo-(1 and 3 wt%)Ag alloys, produced by MAO, targeting biomedical applications. MAO treatment was done by a DC power source, at room temperature, voltage of 300 V, limited current of 2.5 A, for 1 min. The electrolyte was composed by aqueous solution of calcium acetate, sodium β-glycerophosphate and magnesium acetate. Surface analysis was made by EDS, XPS, SEM, XRD, roughness measurements, FTIR and contact angle. The MAO-treated samples exhibited some anatase phase peaks (TiO2) in the XRD patterns, indicating the growth of a crystalline oxide layer. There was pore formation along the outer region of the oxide, with average size of 1 μm. EDS results indicated the predominance of elements Ti and Zr and the successful incorporation of Ca, P and Mg ions in the oxide layers. The roughness increased after treatment, while the contact angle decreased. The produced porous oxide layers, enriched with Ca, P and Mg, high roughness and low contact angle, can possess high potential to be applied in biomedical implants, once it could favor osseointegration and bioactive processes. References: [1] D. R. N. Correa et al., Advanced Materials Research 922, 75-80 (2014) [2] D. R. N. Correa et al., Surface and Coatings Technology 344, 373-382 (2018). (author)