Introduction: Silver nanoparticles have been extensively investigated in dental and orthopedic materials. However, the impregnation of bone graft with silver nanoparticles has been poorly investigated. Objectives: The aim of this study was to evaluate the in vitro antibiofilm activity of a bovine bone impregnated with silver nanoparticles. Methods: Bone scaffolds from cancellous bovine femur were used for the tests and impregnated with silver nanoparticles (50nm) by physical adsorption. Silver nitrate minimal inhibitory and bactericidal concentration were performed Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Enterococcus faecalis, Acinetobacter baumannii, and Escherichia coli. Disc diffusion tests for silver nanoparticles susceptibility and quantification of biofilm production on plate and bone with sessile cell count were also performed. Results: All pathogens were susceptible to silver with low minimal inhibitory concentration (0.25 – 4 mg/L). The scaffold impregnated with silver nanoparticles presented a significant reduction in the biofilm cells for all microorganisms with a reduction of more than 3 logs in colony forming units count. Conclusion: Bone scaffolds impregnated with silver nanoparticles can significantly reduce biofilm, and it can be a strategical material to be used as an implant for different approaches.

Background: Antibiofilm activity of silver nanoparticles has been extensively investigated in common bacteria. Metallo-β-lactamase producing Gram-negative bacteria are hard-to-treat microorganisms with few therapeutic options, and silver nanoparticles were not evaluated on the biofilm of these bacteria. Objectives: The aim of this study was to evaluate the antibiofilm activity of a bone scaffold impregnated with silver nanoparticles in NDM-producing Gram-negative bacilli. Methods: Bone scaffolds from bovine femur were used for the tests and impregnated with silver nanoparticles (50 nm) by physical adsorption. Silver nitrate minimal inhibitory and bactericidal concentrations (MIC and MBC) were performed on NDM-producing Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Disc diffusion tests for silver nanoparticles susceptibility and quantification of biofilm production on plate and bone with sessile cell count were performed. Results: The MIC results demonstrated that silver nitrate had an antimicrobial effect on all microorganisms, inactivating the growth of isolates from a concentration of 8 µg/mL. MBC results showed that E. coli 16.211 was the only isolate to present MIC different from MBC, with a value of 16 µg/mL. Conclusion: Bone scaffolds impregnated with silver nanoparticles can significantly reduce biofilm, and it can be a strategic material to be used as an implant for different approaches.