In vitro bactericidal effect of ultrasonically sol–gel-coated novel CuO/TiO2/PEG/cotton nanocomposite for wound care

Protection against bacterial contamination remains a demand for healthcare textiles such as wound dressings to reduce or eliminate hospital-acquired infections related to antibiotic-resistant bacteria. We report herein a simple and straightforward in situ approach to deposit copper oxide and titanium oxide nanoparticles onto cotton fabric using a sonochemical-mediated sol–gel method. Modification of the cotton surface was achieved by incorporation of citric acid (CA) and polyethylene glycol (PEG) to improve the attachment of the nanoparticles and reduce the attachment of bacteria to the cotton surface, respectively. The resultant cotton fabric was used against Escherichia coli as a Gram-negative bacterium and Staphylococcus aureus as a Gram-positive bacterium in dark condition as an in vitro model for treatment of bacterial wound infection. The effects of different treatment parameters including duration and frequency of ultrasonic irradiation, surface modification with PEG and/or CA, and cotton chemical composition with different metal oxide molar ratios on the antibacterial activity of the treated cotton fabric were studied. All treated cotton fabrics showed antibacterial activity, with higher efficiency for those coated with CuO or CuO/TiO₂ (1:1 molar ratio) among the single metal oxide and composite-modified cotton fibers, respectively. Our results show that such functionalized cotton fibers could actively fight the spread of bacterial infections by preventing bacterial adhesion, enabling more efficient bonding, and ultrasonically promoting generation of nanoparticles and their strong adhesion to the fabric surface.