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This study considers the regularities in the formation of amorphous–crystalline coatings with zinc oxide and wollastonite particles via micro-arc oxidation (MAO) on metal substrates made from a Mg-0.8 wt.% Ca alloy. The combination of components with increased antibacterial and osteogenic properties made it possible to obtain a unique bioactive and corrosion-resistant coating that slowed down the bioresorption of a magnesium implant and stimulated the processes of osteointegration. The coating was examined using various methods, including scanning and transmission electron microscopy, X-ray crystallography, scratch testing, energy-dispersive X-ray spectroscopy, and potentiodynamic polarization testing. As a result of plasma-chemical interactions between electrolyte components and the magnesium substrate, a porous amorphous–crystalline coating comprising wollastonite (CaSiO3), zinc oxide (ZnO), forsterite (Mg2SiO4), and periclase (MgO) was formed at varying voltages (350–500 V) during the MAO process. The protective properties of the coating were exceptional, as evidenced by the mass loss values of the coated samples (1.4–2.3%) in 0.9% NaCl solution, which were significantly lower than the mass loss of the uncoated alloy (8.9%). The coating synthesized at a voltage of 500 V was characterized by a maximum zinc content of 8 at.%, which was responsible for the highest antibacterial activity against Staphylococcus aureus (99.1%).

The present study showcases a novel effective technique for the surface modification of micro-arc diatomite coatings using low-energy, high-current electron beams (LEHCEBs). A variety of methods such as scanning electron microscopy, energy-dispersive X-ray spectroscopy, the X-ray diffraction method, scratch testing, the potentiodynamic polarization method, immersion testing in SBF, and flow cytometry have been used to study the coatings. During processing, the electron beams’ energy density ranged between 2.5–7.5 J/cm2. After the LEHCEB treatment, the surface morphology of the coatings changed completely. The corrosion resistance of the LEHCEB-treated coated samples increased significantly, as evidenced by the decrease in corrosion current to 4.6 × 10−10 A·cm−2 and the increase in polarization resistance to 1.4 × 108 Ω·cm2. The electron beam treatment also increased the adhesion strength of the coatings to the magnesium substrate by 1.8–2.5 times compared to untreated coatings. Additionally, biological studies have shown the high viability of the NIH/3T3 cell line after contact with the samples of the coating extracts.

The method of micro-arc oxidation has been utilized to synthesize a protective biocompatible coating for a bioresorbable orthopedic Mg implant. This paper presents the results of comprehensive research of micro-arc coatings based on diatomite—a biogenic material consisting of shells of diatom microalgae. The main focus of this study was the functionalization of diatomite-based micro-arc coatings by incorporating particles of titania (TiO2) into them. Various properties of the resulting coatings were examined and evaluated. XRD analysis revealed the formation of a new magnesium orthosilicate phase—forsterite (Mg2SiO4). It was established that the corrosion current density of the coatings decreased by 1–2 orders of magnitude after the inclusion of TiO2 particles, depending on the coating process voltage. The adhesion strength of the coatings increased following the particle incorporation. The processes of dissolution of both coated and uncoated samples in a sodium chloride solution were studied. The in vitro cell viability was assessed, which showed that the coatings significantly reduced the cytotoxicity of Mg samples.

Biodegradable materials are currently attracting the attention of scientists as materials for implants in reconstructive medicine. At the same time, ceramics based on calcium silicates are promising materials for bone recovery, because Ca2+ and Si2+ ions are necessary for the mineralization process, and they take an active part in the formation of apatite. In the presented research, the protective silicate biocoatings on a Mg0.8Ca alloy were formed by means of the micro-arc oxidation method, and the study of their morphology, structure, phase composition, corrosion, and biological properties was carried out. Elongated crystals and pores were uniformly distributed over the surface of the coatings. The coated samples exhibited remarkable anti-corrosion properties in comparison with bare magnesium alloy because their corrosion current decreased 10 times, and their corrosion resistance increased almost 100 times. The coatings did not significantly affect the viability of the cells, even without the additional dilution of the extract, and were non-toxic according to ISO 10993-5: 2009. In this case, there was a significant difference in toxicity of the pure Mg0.8Ca alloy and the coated samples. Thus, the results demonstrated that the applied coatings significantly reduced the toxicity of the alloy.

The additive manufacturing of low elastic modulus alloys that have a certain level of porosity for biomedical needs is a growing area of research. Here, we show the results of manufacturing of porous and dense samples by a laser powder bed fusion (LPBF) of Ti-Nb alloy, using two distinctive fusion strategies. The nanostructured Ti-Nb alloy powders were produced by mechanical alloying and have a nanostructured state with nanosized grains up to 90 nm. The manufactured porous samples have pronounced open porosity and advanced roughness, contrary to dense samples with a relatively smooth surface profile. The structure of both types of samples after LPBF is formed by uniaxial grains having micro- and nanosized features. The inner structure of the porous samples is comprised of an open interconnected system of pores. The volume fraction of isolated porosity is 2 vol. % and the total porosity is 20 vol. %. Cell viability was assessed in vitro for 3 and 7 days using the MG63 cell line. With longer culture periods, cells showed an increased cell density over the entire surface of a porous Ti-Nb sample. Both types of samples are not cytotoxic and could be used for further in vivo studies.