Microstructure, mechanical property, biodegradation behavior, and biocompatibility of biodegradable Fe-Fe2O3...

Area of Science:

• Biomaterials Science
• Materials Engineering
• Corrosion Science

Background:

• Biodegradable metallic materials are crucial for temporary medical implants like stents.
• Iron-based alloys are being explored as alternatives to magnesium and zinc due to their tunable degradation rates and mechanical properties.
• Understanding the influence of alloying elements on the performance of iron composites is essential for developing effective biomedical devices.

Purpose of the Study:

• To investigate the effects of varying Fe2O3 content on the microstructure, mechanical properties, corrosion behavior, and in vitro biocompatibility of Fe-Fe2O3 composites.
• To evaluate Fe-Fe2O3 composites as potential novel biodegradable metallic materials for stent applications.
• To determine the optimal composition for a biodegradable stent with enhanced performance.

Main Methods:

• Spark plasma sintering was used to fabricate Fe-Fe2O3 composites with Fe2O3 additions of 2, 5, 10, and 50 wt %.
• X-ray diffraction analysis and optical microscopy were employed to characterize the composite's microstructure.
• Electrochemical measurements and immersion tests were conducted to assess corrosion behavior.
• In vitro biocompatibility was evaluated using cell viability assays (ECV304, L929, vascular smooth muscle cells) and hemocompatibility tests.

Main Results:

• The composites were found to consist of α-Fe and FeO, not Fe2O3.
• Fe-2Fe2O3 and Fe-5Fe2O3 composites exhibited faster degradation rates compared to pure iron.
• Fe-5Fe2O3 demonstrated the highest corrosion rate among the studied composites.
• While showing no cytotoxicity to ECV304 and L929 cells, extracts reduced vascular smooth muscle cell viability.
• All Fe-Fe2O3 composites and pure iron displayed good hemocompatibility.

Conclusions:

• Fe-Fe2O3 composites are a viable novel-structure biodegradable metallic material.
• The Fe-5Fe2O3 composite presents a promising alternative for biodegradable stent applications.
• This composite offers an advantageous combination of an elevated corrosion rate, enhanced mechanical properties, and excellent biocompatibility.