Physico-Chemical And Antimicrobial Properties Of Ag/Ta2o5 Nanocomposite Coatings

Surface modification of surgical instruments is carried out in order to improve the antibacterial performance against the surgical site infections. Healthcare acquired infections (HAI) and Nosocomial infections are one of the leading causes of complications/deaths after surgery. There is an increasing trend of antibiotic resistance in bacteria such as, vancomycin-resistant Enterococcus (VRE), carbapenem-resistant Enterobacteriaceae (CRE), multi-drug-resistant Mycobacterium tuberculosis (MDR-TB), methicillin-resistant Staphylococcus aureus (MRSA), and Neisseria gonorrhoeae. Thus, surfaces that counteract the adherence and growth of bacteria are employed to avoid the infections. In present study, stainless steel 316 L (SS 316 L) was coated with Silver/ Tantalum oxide (Ag/Ta2O5) nanocomposite using reactive magnetron sputtering. The as-sputtered Ag/Ta2O5 nanocomposite (a-Ag/Ta2O5) film was crystallized via thermal treatment at 400 degrees C. Due to the annealing, the AgNPs migrated to the surface through the columnar paths of the a-Ag/Ta2O5. Thus, the crystallized layer (c-Ag/ Ta2O5) exhibited 302% improvement in adhesion strength and enhanced hydrophopibicity. The c-Ag/Ta2O5 also demonstrated excellent antibacterial performance against Staphylococcus aureus (NCTC 6571) (gram-positive bacteria) and Escherichia coli (ATCC 15597) (gram-negative bacteria) according to the inhibition zone measurements. These results suggest that c-Ag/Ta2O5 deposition on SS 316 L substrate has a high potential to serve as an adherent, antibacterial layer on the surgical tools, in order to resist surgical site infections.