Iron-Gold Composites for Biodegradable Implants: In Vitro Investigation on Biodegradation and Biomineralization

Area of Science:

• Biomaterials Science
• Materials Engineering
• Biomedical Engineering

Background:

• Iron (Fe) is a promising material for biodegradable metallic implants due to its biocompatibility.
• The slow degradation rate of pure iron limits its application in tissue regeneration.
• Noble metals can enhance iron's degradation rate through galvanic coupling.

Purpose of the Study:

• To investigate the effect of low concentrations of gold (Au) on the degradation rate and bioactivity of iron.
• To assess the potential of iron-gold (Fe-Au) composites as improved biodegradable metallic implants.

Main Methods:

• Electrochemical corrosion tests were performed on pure Fe and Fe samples with 1.25 and 2.37 μg/g Au.
• Immersion tests and electrochemical impedance spectroscopy were conducted in simulated body fluid (SBF).
• Cytotoxicity was evaluated using L929-murine fibroblast cells.

Main Results:

• Au-containing Fe samples exhibited 4x and 9x faster degradation rates compared to pure Fe.
• Fe-Au composites showed enhanced bioactivity and increased in situ hydroxyapatite formation.
• No toxicity was observed in L929-murine fibroblast cells exposed to Fe-Au composites.

Conclusions:

• Low concentrations of gold effectively enhance the biodegradation rate of iron.
• Fe-Au composites promote biomineralization and exhibit good biocompatibility.
• Fe-Au composites are suitable for tailoring biodegradation and improving Fe-based implants.