Magnesium and its alloys are materials that show great promise for use in bioresorbable implants, due to their unique mechanical properties and biocompatibility. However, their widespread use is limited due to active biocorrosion, which results in the release of excess magnesium ions and gaseous hydrogen, as well as premature loss of the mechanical properties. The solution to this problem is to control of biodegradation rate using nanocoatings.

The present study investigated the regulation of biocorrosion and biocompatibility of the MA2-1pch magnesium alloy using Al₂O₃ and TiO₂ nanocoatings applied by atomic layer deposition (ALD). Coatings with a thickness ranging from 20 to 100 nanometres were synthesised at temperatures between 100 and 300°C. Trimethylaluminium was used for Al₂O₃, while titanium tetrachloride (TiCl₄) or titanium tetraisopropoxide (TTIP) was used for TiO₂.

It was determined through scanning electron microscopy (SEM) that the coatings exhibited high continuity and uniformity. The Al₂O₃ and TiO₂-TTIP coatings are amorphous, while TiO₂-TiCl₄ consists of crystalline grains with an anatase structure. X-ray photoelectron spectroscopy confirmed the absence of magnesium and zinc on the surface, thereby indicating the conformality of the coatings.

The study of biocorrosion was conducted by measuring the pH, hydrogen evolution, and sample mass loss in Ringer's physiological, phosphate-buffered saline, and simulated body fluid solutions. Amorphous coatings have been demonstrated to reduce biocorrosion with increasing thickness. In contrast, minimal corrosion was observed at thickness of 40 nm for crystalline TiO₂.

The evaluation of biocompatibility was conducted through the analysis of the MG-63 osteoblast-like cells, utilising both SEM and fluorescence microscopy. The cytotoxic effect of excess magnesium ions and the effective protection afforded by the Al₂O₃ coating were confirmed using the MTT test. TiO₂-TTIP and Al₂O₃ samples did not manifest any significant signs of toxicity.