Silver nanocluster/silica composite coatings obtained by sputtering for antibacterial applications

Abstract

Silver nanocluster silica composite coatings were deposited by radio frequency co-sputtering technique on several substrates. This versatile method allows tailoring of silver content and antibacterial behaviour of coatings deposited on glasses, ceramics, metals and polymers for several applications. Coating morphology and composition as well as nanocluster size were analyzed by means of UV-Visible absorption, X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), electron dispersive spectroscopy (EDS), X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM). The antibacterial effect was verified through the inhibition halo test against standard bacterial strain, Staphylococcus aureus, before and after sterilization process. Tape test demonstrated a good adhesion of the coatings to the substrates.

Biocompatibility versus peritoneal mesothelial cells of polypropylene prostheses for hernia repair, coated with a thin silica/silver layer

“…In particular, the plasma on the Ag target was powered for 1 second of each 24 second period throughout the deposition time of 15 minutes (1–24/15). The chemical and physical characterization of the antibacterial layer is described in detail elsewhere …”

“…A number of different methods may be used to deposit a thin film containing Ag, including plasma spray, ion beam assisted deposition, magnetron sputtering, micro‐arc oxidation, and the sol–gel process . For this study, the method of Radio Frequency (RF) magnetron co‐sputtering of Ag and SiO 2 was chosen …”

Electrophoretic deposition of lawsone loaded bioactive glass (BG)/chitosan composite on polyetheretherketone (PEEK)/BG layers as antibacterial and bioactive coating

“…There is an ever increasing need for developing antibacterial surfaces of implants that can combat the colonization of antibiotic resistant micro‐organisms . The local delivery of biologically active agents can reduce the risk of infections by providing high local concentrations in a controlled manner …”

How can bioactive glasses be useful in ocular surgery?

“…The coating, whose thickness can be modulated from 10 nm to 1 lm, is produced by radiofrequency cosputtering of silver and silica and is constituted by silver nanoclusters embedded in an amorphous silica (silica glass) matrix. The antiseptic effect was demonstrated in vitro (using S. aureus) and is due to the release of silver ions, [95][96][97] that are not associated to problems of bacterial resistance like in the case of antibiotic treatments. This approach is promising but further in vitro tests with the relevant cell types (e.g., orbital fibroblasts) and in vivo studies in an animal model have to be performed to draw definite conclusions about the suitability of the coating: in fact, the ocular environment is highly complex and several parameters should be taken in account, including the solubility of the silica matrix, the interaction of released metal ions with the tears and the possible ion-induced eye tissue necrosis.…”