Optimizing surface properties of Ti13Nb13Zr alloy substrate for biomedical applications through modification with nano-alumina obtained by atomic layer deposition and hydroxyapatite coatings

Abstract

Ti13Nb13Zr (TNZ) alloys have attracted the interest of researchers as viable and controllable alternatives for biometrics. The research on bioactive coatings of metal alloys has contributed to successful bone therapy by accelerating the osseointegration process. In this context, we present a study on the surface modifications of the TNZ alloy substrate ultrafine-grained (UFG) by severe plastic deformation using high-pressure torsion. Nano-Al2O3 coatings by atomic layer deposition (ALD) and low-temperature hydroxyapatite by electrodeposition (EDP) and simulated body fluid (SBF) were used. We also investigated the cytotoxicity of all surface modifications obtained up to 72 h on osteoblasts. An alumina film was obtained by thermal ALD at 150 °C (nano-Al2O3-TNZ) to enhance the deposition of HAp on the nanostructured substrate obtained by EDP (HAp1-Al2O3-TNZ) and SBF (HAp2-Al2O3-TNZ). The results of the coating processes were analyzed by different techniques such as AFM, SEM, XRD, EDS, and Raman spectroscopy. The coated HAp1-Al2O3-TNZ and HAp2-Al2O3-TNZ samples showed dense and uniform bilayer surface formation. We noticed that surface modification directly influenced the roughness of the TNZ sample independently of the method used. Our surface modification of the TNZ alloy using ALD and HAp from two applied methods showed no cytotoxicity and increased cell proliferation. Therefore, these surface modifications represent a strategy for obtaining a bioactive alloy that can be used as a bone implant.