UCLA

Implant-associated bacterial infections are one of the most serious complications in orthopedic surgery. Treatment of these infections often requires multiple operations, device removal, long-term systemic antibiotics, and extended rehabilitation, and is frequently ineffective, leading to worse clinical outcomes and increased financial costs. In the current study, we found that silver nanoparticle/poly (DL-lactic-co-glycolic acid) (PLGA)-coated metal materials have bactericidal activity in a silver-proportion-dependent manner and inhibit bacterial adherence and biofilm formation in vitro, ex vitro and in vivo. Interestingly, we also found silver nanoparticle/PLGA-coated stainless steel (SNPSA) materials have osteoinductivity they promoted MC3T3-E1 pre-osteoblast proliferation and osteogenesis in vitro and bone formation in rat femoral canal and intramedullary rod models. On the other hand, silver nanoparticle/PLGA-coated titanium (SNPT) materials did not show osteoinductivity. By comparing the surface properties of SNPSA and SNPT materials, we determined that SNPSA materials exhibit higher surface electrostatic potential than SNPT that may provide a stronger electric stimulation for bone regeneration. In addition, we found that SNPSA materials have higher surface free energy and hydrophilicity than SNPT materials that may enhance protein absorption and subsequently bone formation. Taken together, our results indicate that silver nanoparticle/PLGA coating of stainless steel is a practical process for implants of orthopedic to control implant-associated infections and improve bone healing.