4 research outputs found
Enhanced Bactericidal Activity of Silver Thin Films Deposited via Aerosol-Assisted Chemical Vapor Deposition
Silver thin films were deposited on SiO2-barrier-coated float glass, fluorine-doped tin oxide (FTO) glass, Activ glass, and TiO2-coated float glass via AACVD using silver nitrate at 350 °C. The films were annealed at 600 °C and analyzed by X-ray powder diffraction, X-ray photoelectron spectroscopy, UV/vis/near-IR spectroscopy, and scanning electron microscopy. All the films were crystalline, and the silver was present in its elemental form and of nanometer dimension. The antibacterial activity of these samples was tested against Escherichia coli and Staphylococcus aureus in the dark and under UV light (365 nm). All Ag-deposited films reduced the numbers of E. coli by 99.9% within 6 h and the numbers of S. aureus by 99.9% within only 2 h. FTO/Ag reduced bacterial numbers of E. coli to below the detection limit after 60 min and caused a 99.9% reduction of S. aureus within only 15 min of UV irradiation. Activ/Ag reduced the numbers of S. aureus by 66.6% after 60 min and TiO2/Ag killed 99.9% of S. aureus within 60 min of UV exposure. More remarkably, we observed a 99.9% reduction in the numbers of E. coli within 6 h and the numbers of S. aureus within 4 h in the dark using our novel TiO2/Ag system
Potent Antibacterial Activity of Copper Embedded into Silicone and Polyurethane
A simple,
easily up-scalable swell–encapsulation–shrink technique
was used to incorporate small 2.5 nm copper nanoparticles (CuNPs)
into two widely used medical grade polymers, polyurethane, and silicone,
with no significant impact on polymer coloration. Both medical grade
polymers with incorporated CuNPs demonstrated potent antimicrobial
activity against the clinically relevant bacteria, methicillin-resistant Staphylococcus aureus and Escherichia
coli. CuNP-incorporated silicone samples displayed
potent antibacterial activity against both bacteria within 6 h. CuNP-incorporated
polyurethane exhibited more efficacious antimicrobial activity, resulting
in a 99.9% reduction in the numbers of both bacteria within just 2
h. With the high prevalence of hospital-acquired infections, the use
of antimicrobial materials such as these CuNP-incorporated polymers
could contribute to reducing microbial contamination associated with
frequently touched surfaces in and around hospital wards (e.g., bed
rails, overbed tables, push plates, etc.)
Enhancing the antibacterial activity of light-activated surfaces containing crystal violet and ZnO nanoparticles: investigation of nanoparticle size, capping ligand, and dopants
Healthcare-associated infections pose a serious risk for patients, staff, and visitors and are a severe burden on the National Health Service, costing at least £1 billion annually. Antimicrobial surfaces significantly contribute toward reducing the incidence of infections as they prevent bacterial adhesion and cause bacterial cell death. Using a simple, easily upscalable swell-encapsulation-shrink method, novel antimicrobial surfaces have been developed by incorporating metal oxide nanoparticles (NPs) and crystal violet (CV) dye into medical-grade polyurethane sheets. This study compares the bactericidal effects of polyurethane incorporating ZnO, Mg-doped ZnO, and MgO. All metal oxide NPs are well defined, with average diameters ranging from 2 to 18 nm. These materials demonstrate potent bactericidal activity when tested against clinically relevant bacteria such as Escherichia coli and Staphylococcus aureus. Additionally, these composites are tested against an epidemic strain of methicillin-resistant Staphylococcus aureus (MRSA) that is rife in hospitals throughout the UK. Furthermore, we have tested these materials using a low light intensity (∼500 lx), similar to that present in many clinical environments. The highest activity is achieved from polymer composites incorporating CV and ∼3 nm ZnO NPs, and the different performances of the metal oxides have been discussed