Exploring multielement nanogranular coatings to forestall implant-related infections

Introduction: As we approach the post-antibiotic era, the development of innovative\r\nantimicrobial strategies that carry out their activities through non-specific mechanisms\r\ncould limit the onset and spread of drug resistance. In this context, the use of\r\nnanogranular coatings of multielement nanoparticles (NPs) conjugated to the surface\r\nof implantable biomaterialsmight represent a strategy to reduce the systemicdrawbacks\r\nby locally confining the NPs effects against either prokaryotic or eukaryotic cells.\r\nMethods: In the present study, two new multielement nanogranular coatings\r\ncombining Ag and Cu with either Ti or Mg were synthesized by a gas phase physical\r\nmethod and tested against pathogens isolated from periprosthetic joint infections to\r\naddress their potential antimicrobial value and toxicity in an in vitro experimental setting.\r\nResults: Overall, Staphylococcus aureus, Staphylococcus epidermidis and\r\nEscherichia coli displayed a significantly decreased adhesion when cultured on\r\nTi-Ag-Cu and Mg-Ag-Cu coatings compared to uncoated controls, regardless of\r\ntheir antibiotic resistance traits. A dissimilar behavior was observed when\r\nPseudomonas aeruginosa was cultured for 30 and 120 minutes upon the surface\r\nof Ti-Ag-Cu and Mg-Ag-Cu-coated discs. Biofilm formation was mainly reduced\r\nby the active effect of Mg-Ag-Cu compared to Ti-Ag-Cu and, again, coatings had a\r\nmilder effect on P. aeruginosa, probably due to its exceptional capability of\r\nattachment and matrix production. These data were further confirmed by the\r\nevaluation of bacterial colonization on nanoparticle-coated discs through\r\nconfocal microscopy. Finally, to exclude any cytotoxic effects on eukaryotic\r\ncells, the biocompatibility of NPs-coated discs was studied. Results\r\ndemonstrated a viability of 95.8% and 89.4% of cells cultured in the presence of\r\nTi-Ag-Cu and Mg-Ag-Cu discs, respectively, when compared to negative controls.\r\nConclusion: In conclusion, the present study demonstrated the promising antiadhesive\r\nfeatures of both Ti-Ag-Cu and Mg-Ag-Cu coatings, as well as their action\r\nin hampering the biofilm formation, highlighting the safe use of the tested multielement\r\nfamilies of nanoparticles as new strategies against bacterial attachment to\r\nthe surface of biomedical implants.