Highly Efficient F, Cu Doped TiO2 Anti-bacterial Visible Light Active Photocatalytic Coatings to Combat Hospital-Acquired Infections

Bacterial infections are a major threat to the health of patients in healthcare facilities including hospitals. One of the major causes of patient morbidity is infection with Staphylococcus aureus. One of the the most dominant nosocomial bacteria, Methicillin Resistant Staphylococcus aureus (MRSA) have been reported to survive on hospital surfaces (e.g. privacy window glasses) for up to 5 months. None of the current anti-bacterial technology is efficient in eliminating Staphylococcus aureus. A novel transparent, immobilised and superhydrophilic coating of titanium dioxide, co-doped with fluorine and copper has been prepared on float glass substrates. Antibacterial activity has demonstrated (by using Staphylococcus aureus), resulting from a combination of visible light activated (VLA) photocatalysis and copper ion toxicity. Co-doping with copper and fluorine has been shown to improve the performance of the coating, relative to a purely fluorine-doped VLA photocatalyst. Reductions in bacterial population of log10 = 4.2 under visible light irradiation and log10 = 1.8 in darkness have been achieved, compared with log10 = 1.8 under visible light irradiation and no activity, for a purely fluorine-doped titania. Generation of reactive oxygen species from the photocatalytic coatings is the major factor that significantly reduces the bacterial growth on the glass surfaces

Biodegradable poly(ester urethane)urea scaffolds for tissue engineering: interaction with osteoblast-like MG-63 cells

Porous three-dimensional scaffolds with potential for application as cancellous bone graft substitutes were prepared from aliphatic segmented poly(ester urethane) urea using the phase-inverse technique. Proton nuclear magnetic resonance, size-exclusion chromatography, electron spectroscopy for chemical analysis, secondary ion mass spectrometry, infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, computed tomography and mechanical tests were carried out, to characterize the scaffolds’ physicochemical properties. Human osteosarcoma MG-63 cells were seeded into the scaffolds for 1, 2, 3 and 4 weeks to evaluate their potential to support attachment, growth and proliferation of osteogenic cells. The scaffold–cell interaction was assessed by analysis of DNA content, total protein amount, alkaline phosphatase activity and WST-1 assay. The scaffolds supported cell attachment, growth and proliferation over the whole culture period of 4 weeks (DNA, total protein amount). There was, however, a reduction in the WST-1 assay values at 4 weeks, which might suggest a reduction in the rate of cell proliferation at this time

Highly efficient F, Cu doped TiO2 anti-bacterial visible light active photocatalytic coatings to combat hospital-acquired infections

Bacterial infections are a major threat to the health of patients in healthcare facilities including\ud hospitals. One of the major causes of patient morbidity is infection with Staphylococcus aureus. One\ud of the the most dominant nosocomial bacteria, Methicillin Resistant Staphylococcus aureus (MRSA)\ud have been reported to survive on hospital surfaces (e.g. privacy window glasses) for up to 5 months.\ud None of the current anti-bacterial technology is efficient in eliminating Staphylococcus aureus. A novel\ud transparent, immobilised and superhydrophilic coating of titanium dioxide, co-doped with fluorine and\ud copper has been prepared on float glass substrates. Antibacterial activity has demonstrated (by using\ud Staphylococcus aureus), resulting from a combination of visible light activated (VLA) photocatalysis and\ud copper ion toxicity. Co-doping with copper and fluorine has been shown to improve the performance of\ud the coating, relative to a purely fluorine-doped VLA photocatalyst. Reductions in bacterial population of\ud log10 = 4.2 under visible light irradiation and log10 = 1.8 in darkness have been achieved, compared with\ud log10 = 1.8 under visible light irradiation and no activity, for a purely fluorine-doped titania. Generation\ud of reactive oxygen species from the photocatalytic coatings is the major factor that significantly reduces\ud the bacterial growth on the glass surfaces

Antibacterial properties of F-doped ZnO visible light photocatalyst.

Nanocrystalline ZnO photocatalysts were prepared by a sol-gel method and modified with fluorine to improve their photocatalytic anti-bacterial activity in visible light. Pathogenic bacteria such as Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) were employed to evaluate the antimicrobial properties of synthesized materials. The interaction with biological systems was assessed by analysis of the antibacterial properties of bacteria suspended in 2% (w/w) powder solutions. The F-doping was found to be effective against S. aureus (99.99% antibacterial activity) and E. coli (99.87% antibacterial activity) when irradiated with visible light. Production of reactive oxygen species is one of the major factors that negatively impact bacterial growth. In addition, the nanosize of the ZnO particles can also be toxic to microorganisms. The small size and high surface-to-volume ratio of the ZnO nanoparticles are believed to play a role in enhancing antimicrobial activity