Drug-eluting biodegradable metals and metal-ceramic composites

Biodegradable metals emerged as promising temporary bone implants. The integration of local drug delivery (LDD) can prevent biomaterial-centered infections that are difficult to treat. LDD is achieved by drug-eluting coatings or porous implants where the drug is impregnated after implant fabrication because the high temper-atures used during conventional production processes would result in their thermal decomposition. This work reports on the production and characterization of vancomycin hydrochloride (VH)-loaded Fe and Fe-iron oxide (Fe2O3) composites (Fe-Fe2O3) by a cold sintering technique. We use focused ion beam milling for the first time to investigate the drug-metal interface. We investigate the mechanical and degradation properties of VH-free and VH-loaded Fe and Fe-Fe2O3. Results show very high mechanical strength of drug-eluting Fe and Fe-Fe2O3 composites (up to than 780 MPa under compression, exceeding the maximum strength of cancellous bone more than three times) accompanied by a delayed drug release. Then, we confirm the good antimicrobial activity against Staphylococcus aureus and cell compatibility with the murine embryonic fibroblast cell line NIH/3T3 in vitro. Overall results confirm the promise of drug-eluting metals and metal-ceramic composites for LDD in bone.