Biodegradable Mg-Cu alloy implants with antibacterial activity for the treatment of osteomyelitis: Invitro and invivo evaluations.

Abstract

Treatment of chronic osteomyelitis (bone infection) remains a clinical challenge; in particular, it requires an implantable material with improved antibacterial activity. Here, we prepared biodegradable magnesium (Mg)-copper (Cu) alloys with different Cu contents (0.05, 0.1, and 0.25wt%) and assessed their potential for treating methicillin-resistant Staphylococcus aureus-induced osteomyelitis. We evaluated the microstructures, mechanical properties, corrosion behavior, and ion release of the alloys invitro, and their biocompatibility and antibacterial activity invitro and invivo. The antibacterial activity of the Mg-Cu alloys invitro was demonstrated by microbiological counting assays, bacterial viability assays, biofilm formation observations, and the expression of biofilm, virulence, and antibiotic-resistance associated genes. The antibacterial activity of Mg-Cu alloys invivo was confirmed by imaging examination, microbiological cultures, and histopathology. The biocompatibility of Mg-Cu alloys was confirmed by cell proliferation, vitality, and morphology assays invitro and Cu(2+) or Mg(2+) ion assays, blood biochemical tests, and histological evaluation invivo. The alloy containing 0.25wt% Cu exhibited the highest antibacterial activity among the tested alloys, with favorable biocompatibility. Collectively, our results indicate the potential utility of Mg-Cu alloy implants with 0.25wt% Cu in treating orthopedic infections.