Magnetron sputtered magnesium-based thin film metallic glasses for bioimplants

Area of Science:

• Biomaterials Science
• Materials Engineering
• Orthopedic Implants

Background:

• Stress shielding in bone implants arises from the elastic modulus mismatch between metallic implants and human bone.
• Magnesium-based thin film metallic glasses (Mg-based TFMGs) offer a potential solution due to their tunable mechanical properties.
• Developing biocompatible and corrosion-resistant Mg-based TFMGs is crucial for successful orthopedic applications.

Purpose of the Study:

• To fabricate Mg-based TFMGs using ion assisted pulsed DC magnetron sputtering.
• To evaluate the microstructure, mechanical properties, and in vitro performance of these TFMGs.
• To assess the impact of zinc addition on the corrosion resistance and biocompatibility of Mg-based TFMGs.

Main Methods:

• Ion assisted pulsed DC magnetron sputtering for TFMG fabrication.
• X-ray diffractometry, transmission electron microscopy, and X-ray photoelectron spectroscopy for microstructure and composition analysis.
• Electrochemical studies, immersion tests in simulated body fluid, cytotoxicity assays (L929 fibroblast cells), and biomineralization experiments (Saos-2 cells).

Main Results:

• Mg-based TFMGs were successfully fabricated with a hardness of 5.1 GPa.
• Zinc addition significantly improved the corrosion resistance of the Mg-based TFMGs in simulated body fluid.
• In vitro studies confirmed the TFMGs' non-toxicity and ability to promote calcium phosphate formation, indicating good biocompatibility and osteoconductivity.

Conclusions:

• Mg-based TFMGs are a viable candidate for orthopedic implants, effectively mitigating stress shielding.
• The incorporation of zinc enhances the in vitro performance of Mg-based TFMGs, improving corrosion resistance and biocompatibility.
• These findings suggest that zinc-containing Mg-based TFMGs hold significant potential for next-generation bone implant materials.