A Novel Approach to Reducing Spinal Implant-Associated Infections

Implant-associated infection is a severe complication of instrumented spinal surgery. Preventive measures against biofilm formation, such as chemical modifications of devices with antibiotics or bactericidal substances, have been explored to decrease infection rates and enhance therapeutic outcomes. However, this approach remains challenging, and the safety issues associated with antibiotic resistance and cellular toxicity need to be addressed. Hence, there is an unmet clinical need for implants that resist biofilm formation. Ultrafine-grained material (UFG), which has a nanoscale grain structure, is a novel form of metal with exceptional mechanical and biocompatibility properties that may also have antimicrobial activity. This study investigates the extent to which UFG stainless steel implants resist biofilm formation by Staphylococcus aureus in vitro and in vivo. The results show that the UFG stainless steel wire significantly reduced biofilm formation at early time points after bacterial infection compared to a standard wire. In mouse models of implant-associated infection below the skin or the fascia, the UFG wire had significantly less biofilm formation at early time points. The UFG wire appeared to delay initial bacterial adhesion and biofilm maturation. These findings suggest that UFG implants may resist initial biofilm formation and maturation, leading to promising antibacterial materials for patients.