Stepwise antibacterial strategy for orthopedic implants using bacteriophages on electrospun cefiderocol/PCl/Gt nanofibers over PEO-coated Mg3ZnCa.

Antibacterial functionality in clinical orthopedic implants remains an area needing improvement. This study presents a novel, stepwise antibacterial method to prevent implant infections. First, a Mg3ZnCa (ZX31) alloy was selected for its biodegradable properties, then its poor corrosion resistance was enhanced using plasma electrolytic oxidation (PEO). Next, electrospun nanofibers loaded with the antibiotic cefiderocol were applied to the PEO-coated surface. Finally, bacteriophages were immobilized onto the nanofibers. The structure and antibacterial performance of each step were characterized, including electron microscopy imaging of the immobilized phages. Antibacterial testing against Escherichia coli demonstrated that phage-antibiotic co-release achieved complete bacterial eradication within one hour, compared to eight hours for cefiderocol-loaded fibers alone. Additionally, magnesium corrosion contributed to sterilization after ten hours. These results show the strong synergistic potential of combining magnesium degradation, antibiotic delivery, and phage therapy to prevent early-stage infections on orthopedic implants, offering a promising route for future clinical applications.