Enhancing magnesium-based materials for biomedical applications using an innovative strategy of combined single point incremental forming and bioactive coating

Background

Magnesium (Mg) and its alloys are promising candidates for biodegradable materials in next-generation bone implants due to their favourable mechanical properties and biodegradability. However, their rapid degradation and corrosion, potentially leading to toxic byproducts, pose significant challenges for widespread use.

Objectives

This study aimed to address the challenges associated with Mg-based materials by thoroughly evaluating the biocompatibility, genotoxicity, and mechanical properties of Mg-based devices manufactured via Single Point Incremental Forming (SPIF). Additionally, the study explored the efficacy of a bioactive coating in enhancing the biocompatibility of these devices.

Methods

The biocompatibility of six different Mg-SPIF substrates was assessed using an indirect cytotoxicity assay while genotoxicity was evaluated using the Ames test. Mg-based implants were subjected to roughness and thickness tests, as well as metallographic observations. To enhance biocompatibility, a coating comprising sodium hydroxide (NaOH), ascorbic acid (AA), and bovine serum albumin (BSA) was applied to the most promising Mg-SPIF devices.

Results

None of the Mg-SPIF devices demonstrated genotoxicity. Out of the six devices evaluated, only two, which had lower surface roughness, exhibited the most favourable biocompatibility responses. Additionally, the surface functionalization strategy significantly enhanced the biocompatibility of these Mg-SPIF devices, demonstrating up to 70% improvement in cell viability compared to unmodified substrates, indicating substantial enhancement in biological performance.

Conclusions

These results underscore the potential of SPIF Mg-based materials, particularly when enhanced with a bioactive OH-AA-BSA coating, to revolutionize medical implant technology by providing a safer and more effective option for a wide range of biomedical applications. While these in vitro findings are very promising, translation to clinical applications requires comprehensive in vivo validation, focusing on degradation kinetics, local tissue response, and mechanical integrity under physiological conditions.