In vitro assessment of corrosion resistance and biocompatibility of tantalum-niobium oxide surface-functionalized Mg alloy

Magnesium alloys have been considered as temporary biomaterials for orthopedic applications. Despite having great mechanical (bone-like) characteristics and osseointegration, magnesium alloys deteriorate quickly in physiological conditions. Modifying the Mg alloy surface with tantalum-based thin films is an effective process to reduce the rate of corrosion and improve biocompatibility. In the present work, tantalum-niobium oxide nanocomposite thin films were successively deposited on Mg-Al6-Zn1.5-Cu2-Ge0.5 Mg alloys via reactive magnetron sputtering to improve anticorrosion and biocompatibility. Crystallographic structure, surface morphology and chemical compositions were characterized using XRD, TEM, FE-SEM, EDS and XPS. Electrochemical and hydrogen evolution experiments were used to evaluate the resistance to corrosion of the samples. The biocompatibility of the samples was evaluated by cell viability using the osteoblast cell line (MC3T3-E1). Results revealed the existence of the composite thin-film in the crystalline form and the cauliflower-like clustered morphology. Enhancement in the corrosion resistance of nanocomposite coatings was confirmed by a decrease in current density (Icorr) during the polarization studies. The wettability studies revealed the hydrophilic character of the coatings and they are bioactive in simulated body fluid (SBF) after 5 days by the mineralization of calcium phosphate. The hemocompatibility assessment proved that the coatings were blood compatible in nature. MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay on MC3T3-E1 cells showed that tantalumniobium oxide thin films are biocompatible and can stimulate cellular proliferation and differentiation. Overall

In vitro biocompatibility and degradation assessment of tantalum oxide coated Mg alloy as biodegradable implants

In the present study, the sputtering process deposited tantalum oxide thin film onto AZ31B alloy, and the biocompatibility and degradation resistance were evaluated. The phase analysis by X-ray diffraction (XRD) and transmission electron microscopy (TEM) was carried out to understand the Ta-based thin films' crystalline and amorphous nature thin film. The thin film surface chemical composition was investigated by X-ray Photoelectron Spectroscopy (XPS) which showed the elemental signals of O, Ta without any other impurities. Contact angle measurements verified the hydrophobic nature of the coated specimens. The corrosion studies revealed that corrosion resistance was significantly enhanced for the Ta-based thin-film coated Mg alloys than the uncoated bare counterpart by reducing corrosion current density from 2.886 x 10(-4) to 1.20 x 10(-5) A/cm(2). Bioactivity of the coated specimens in SBF immersion showed apatite formation in 5 days. The hemocompatibility studies of the coatings showed the echinocytes morphology of the RBCs. In vitro, MIT assay exhibited more significant cell proliferation and cell viability of 100% at 7 days of incubation. The cell morphology studies showed improved cell attachment and cell growth by controlling magnesium ions' release into the cell culture media. (C) 2022 Elsevier B.V. All rights reserved

Biocompatibility and corrosion evaluation of niobium oxide coated AZ31B alloy for biodegradable implants

Biodegradable magnesium (Mg) based implants have considerable interest in the biomedical field as their use nullifies the necessity for implant removal surgery and avoids the long-standing adverse reaction of permanent bioimplants. The degradation resistance and biocompatibility of the Mg alloys can be improved by coating them with a suitable thin film. Here, thin films of niobium and niobium oxide were developed on the AZ31B Mg alloy by sputtering technique and their biocompatibility and corrosion resistance was examined. X-ray diffraction (XRD) and Transmission electron microscope (TEM) techniques confirmed the crystallinity of the thin films. Subsequently, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) techniques were employed to evaluate the morphology and chemical composition of the thin film surfaces, respectively. Thin-film coated Mg alloys revealed good corrosion resistance compared to their uncoated bare counterparts in simulated body fluid (SBF). The contact angle study was performed on the coated specimens to investigate their wettability which revealed their hydrophobic character. The cell viability studies on thin-film coated specimens exhibited significant cell proliferation, and cell morphological studies showed good cell attachment and growth. The in vitro MTT assay on mouse osteoblast precursor cells (MC3T3-E1) indicated that the Nb-based coatings are cytocompatible and promote cell proliferation

Biological performance of metal metalloid (TiCuZrPd:B) TFMG fabricated by pulsed laser deposition

The aim of our study is to investigate the effect of boron with different ratios in Ti-Cu-Pd-Zr metallic glass (MG) matrix (Ti-Cu-Pd-Zr:B) fabricated by Pulsed Laser Deposition (PLD) for biomedical implants. The Ti based Thin Film Metallic Glasses (TFMGs) in combination with boron (in different atomic %) was assessed in attaining the combined properties, like outstanding corrosion resistant properties and good biocompatibility in this work. The disordered structure and amorphous nature of the Ti-Cu-Pd-Zr:B thin films systems were achieved by the PLD process and affirmed by XRD and transmission electron microscopy. The boron incorporation in the TFMG has been elucidated by XPS analysis. The boron containing films displays distribution of boron protuberances interleaved in the amorphous matrix was stated from SEM analysis. It is found that increase in atomic percentage of boron contents in TFMG results in the improvement in glass transition temperatures. The electrochemical parameters suggest better corrosion resistance and capabilities of passivity when boron percentage was increased in the film thereby preventing adverse biological reactions. TFMGs exhibited excellent hemocompatibility by preventing the platelet activation. MTT assay manifests increase in cell concentration with culture period on the TFMGs for the MC3T3-E1 preosteoblasts cells. Cell morphology was also studied which confirmed the viable state of the cells on the TFMG surfaces. The combination of such distinctive properties marks these TFMG systems as prospective aspirants for biomedical implants