Novel bioactive Fe-based metallic glasses with excellent apatite-forming ability

Area of Science:

• Materials Science
• Biomaterials Engineering
• Biomedical Engineering

Background:

• Metallic glasses are promising biomaterials due to their unique properties.
• Developing new metallic glasses without toxic elements is crucial for biomedical applications.
• Apatite formation ability is a key indicator of a biomaterial's bioactivity.

Purpose of the Study:

• To investigate the apatite-forming ability of niobium-containing metallic glasses.
• To evaluate the bioactivity and surface changes of these alloys in simulated body fluids (SBF).
• To explore the potential of these alloys as next-generation biomaterials for medical implants.

Main Methods:

• Synthesis of (Fe0.75B0.15Si0.1)100-xNbx metallic glasses (x=0, 1, 3 at.%).
• Immersion testing in simulated body fluids (SBF) for 1, 3, and 9 days.
• Surface characterization using Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS).

Main Results:

• The metallic glasses exhibited excellent and spontaneous apatite nucleation and precipitation within 1 day in SBF.
• Bone-like hydroxyapatite (HA) with a Ca/P ratio of 1.65 formed on the surface after 3 days.
• Substrate alloys developed hierarchical nano/macro-porous structures due to selective dissolution of Fe and B, enhancing bioactivity.

Conclusions:

• Niobium-containing metallic glasses demonstrate exceptional bioactivity and apatite-forming ability without toxic elements.
• The alloys facilitate spontaneous apatite layer formation and substrate modification in SBF.
• These materials hold significant promise for applications in orthopedic implants and stents.