Surface modification of magnesium with a novel composite coating for application in bone tissue engineering

Magnesium (Mg) and its alloys are promising candidates for use in bone tissue engineering due to their good biocompatibility and mechanical stability. Nonetheless, the fast biodegradation of Mg in physiological media inhibits its use as a bone graft material. Aiming to improve its corrosion resistance, a dicalcium phosphate dihydrate (DCPD, brushite) coating was initially deposited on the hot-rolled Mg substrates by immersion in a phosphating bath at room temperature for 24 h. Polyvinyl alcohol-bioactive glass (PVA-BG) composite coatings were then deposited by dip-coating on these materials. The samples were tested for structure, corrosion behavior, and biocompatibility. The composite coatings significantly increased the corrosion protection of Mg and also accelerated the formation of HAp on its surface when soaked in a simulated body fluid (SBF). Flow cytometry assays revealed that the composites prepared had high cell viability (over 90%) when immortalized human embryonic kidney cells were tested. The coating method investigated in this work is simple, environmentally friendly, safe, and easily scalable. It is the first time that this approach is reported in the literature, which highlights its novelty. [Display omitted] •Hot-rolled magnesium surface modified to increase its corrosion resistance.•Dicalcium phosphate dihydrate coating deposited by a chemical conversion route.•Polyvinyl alcohol-bioactive glass composite films deposited by dip-coating.•Both the corrosion resistance and biocompatibility increased after the modification.•The obtained composites showed no toxicity to human embryonic kidney cells.