Nanoscale surface modifications on Titanium plates- A strategy to mitigate MRSA biofilm-mediated implant infections:...

Orthopaedic implant infections pose a major threat after implantation. Biofilms of pathogenic bacteria resistant to antibiotics cause biomaterial mediated infections. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the prevalent biofilm-forming pathogens associated with implant infection in high proportion. Loss of effectiveness of antibiotics against these drug-resistant pathogens demands alternative approaches to surmount this crisis. Various strategies involving antibiotics, biocides, and metal ions are employed as the prohibiting steps of biofilm formation. Hence, to prevent biofilm formation and infections caused by biofilms formed over the orthopaedic implants, we involved laser micro-machining to modify the surface of the Titanium (Ti) plate, the most widely used implant material. Interestingly, we found that the laser-peening process generated widespread nanosized pores and micro-roughness to the surface of the Ti plate. Laser-peened Ti plate reduced the adhesion of MRSA over the metal surface and also retained its capacity to inhibit biofilm formation, which was confirmed with scanning electron microscopy (SEM). The biofilm assays like quantification of biofilm by crystal violet, determination of colony forming unit from biofilm formed over the control and laser-peened Ti plates showed that the laser-peened Ti plate significantly reduced the adherence of biofilm-forming MRSA. Moreover, the genes responsible for biofilm adhesion were found to be downregulated which was confirmed by qPCR. From our results, it was found that laser-peened Ti implants would be an alternative strategy to prevent biofilm-mediated infection on orthopaedic implant material.