Antimicrobial Nanostructured Coatings: A Gas Phase Deposition and Magnetron Sputtering Perspective

Abstract

Counteracting the spreading of multi-drug-resistant pathogens, taking place through surface-mediated cross-contamination, is amongst the higher priorities in public health policies. For these reason an appropriate design of antimicrobial nanostructured coatings may allow to exploit different antimicrobial mechanisms pathways, to be specifically activated by tailoring the coatings composition and morphology. Furthermore, their mechanical properties are of the utmost importance in view of the antimicrobial surface durability. Indeed, the coating properties might be tuned differently according to the specific synthesis method. The present review focuses on nanoparticle based bactericidal coatings obtained via magneton-spattering and supersonic cluster beam deposition. The bacteria–NP interaction mechanisms are first reviewed, thus making clear the requirements that a nanoparticle-based film should meet in order to serve as a bactericidal coating. Paradigmatic examples of coatings, obtained by magnetron sputtering and supersonic cluster beam deposition, are discussed. The emphasis is on widening the bactericidal spectrum so as to be effective both against gram-positive and gram-negative bacteria, while ensuring a good adhesion to a variety of substrates and mechanical durability. It is discussed how this goal may be achieved combining different elements into the coating.

The Role of Substrate on Thermal Evolution of Ag/TiO2 Nanogranular Thin Films

“…Figure 1 shows the evolution of the surface morphology of the two films obtained by AFM. The as-deposited films exhibit the usual granular and homogeneous morphology previously reported [4,16,24,25]. For annealing temperatures up to 500 • C, no significant change in the surface structure or grain size can be observed.…”

“…A paradigmatic nanogranular model system to investigate the temperature effects is constituted by a nanostructured film composed of metal and oxide nanoparticles (NPs). Metal/titanium dioxide (TiO 2 ) nanostructures have in fact unique properties for applications in photocatalysis [ 19 , 20 , 21 , 22 , 23 ], antibacterial coatings [ 18 , 24 , 25 ], sensors [ 26 , 27 , 28 , 29 ], solar cells [ 30 , 31 , 32 ] and energy storage [ 33 , 34 ]. The addition of NPs of different materials to a host matrix of TiO 2 usually results in an increase of the stable temperature range of the composite film, due to the pinning force introduced by the NPs that hampers the coalescence and crystallization [ 35 , 36 ].…”

Photocatalytic Activity of Cellulose Acetate Nanoceria/Pt Hybrid Mats Driven by Visible Light Irradiation

“…The surface of the prepared mats was decorated with PtNCs deposited by SCBD, a gas phase synthesis method producing a beam of nanoclusters from a target rod of the desired material [ 24 , 25 ]. In this work, PtNCs were obtained from a Pt rod (purity 99.99%, Alfa Aesar GmbH, Kandel, Germany), using He at pressure P = 50 bar as a carrier gas.…”

Metallic Antibacterial Surface Treatments of Dental and Orthopedic Materials

“…Despite diverse physicochemical properties, different metallic agents could exert antibacterial activities through similar approaches, in brief, disruption or disfunction of cell membrane, interruption of signal transduction, damage of proteins or DNA, oxidation by reactive oxygen species (ROS) and leakage of intracellular contents of bacteria, etc. [ 80 , 84 ].…”