Light-Activated Antimicrobial Surfaces Using Industrial Varnish Formulations to Mitigate the Incidence of Nosocomial Infections

Abstract

Evidence has shown that hospital surfaces are one of the major vehicles of nosocomial infections caused by drug-resistant pathogens. Smart surface coatings presenting multiple antimicrobial activity mechanisms have emerged as an advanced approach to safely prevent this type of infection. In this work, industrial waterborne polyurethane varnish formulations containing for the first time cationic polymeric biocides (SPBs) combined with photosensitizer curcumin were developed to afford contact-active and light-responsive antimicrobial surfaces. SPBs were prepared by atom transfer radical polymerization, which allows control over the polymer features that influence antimicrobial efficiency (e.g., molecular weight), while natural curcumin was employed to impart photodynamic activity to the surface. Antibacterial testing against Gram-negative Escherichia coli revealed that glass surfaces coated with the new formulations displayed photokilling effect under white-light (42 mW/cm2) irradiation within only 15 min of exposure. In addition, it was observed a combined antimicrobial effect between the two biocides (cationic SPB and curcumin), with a higher reduction in the number of viable bacteria observed for the surfaces containing cationic SPB/curcumin mixtures in comparison with the one obtained for surfaces only with polymer or without biocides. The waterborne industrial varnish formulations allowed the formation of homogeneous films without the need for addition of a coalescing agent, which can be potentially applied in diverse surface substrates to reduce bacterial transmission infections in healthcare environments.

Antimicrobial Photodynamic Therapy: Latest Developments with a Focus on Combinatory Strategies

“…As an illustration, Müller et al reported polyethersulfone membranes doped with polycationic PS that provide antimicrobial properties for potential use as filter membranes in water purification or medicine [340]. Other recent distinctive systems for aPDI refer to self-sterilizing and photoactive antimicrobial surfaces made from (i) natural polymers such as chitosan doped with chlorophyll [336], (ii) "bioplastic" poly(lactic acid) surfaces coated with a BODIPY PS [341], or (iii) synthetic polyurethanes doped with curcumin and cationic bacterial biocides [336,[342][343][344][345].…”

From Antibacterial to Antibiofilm Targeting: An Emerging Paradigm Shift in the Development of Quaternary Ammonium Compounds (QACs)

“…Although the FRP technique is one of the main methods for obtaining QA-based polymers in terms of scaling up the process, controlled radical polymerization (CPR) methods allow precise control of the molecular weight and macromolecular structure of the resulting polymer, which is important for obtaining better antibacterial activity. CRP techniques, such as atom transfer radical polymerization (ATRP), − reversible addition–fragmentation chain transfer (RAFT), ,, and nitroxide-mediated polymerization (NMP) are being actively studied to create QA-antibacterial coatings. In addition, the literature describes examples of obtaining QA-functionalized surfaces/materials using ring-opening polymerization and click chemistry methods. , …”

Scalable Fabrication of Superhydrophobic Coating with Rough Coral Reef‐Like Structures for Efficient Self‐Cleaning and Oil‐Water Separation: An Experimental and Molecular Dynamics Simulation Study

“…because of i) its lower cost and environmental friendliness, which greatly increases the potential for large-scale applications; ii) its lower film-forming temperature (as low as 0 °C), which broadens the environmental applicability without high temperature curing; iii) its higher weather resistance, which would be beneficial to improve outdoor application ability. [40][41][42][43] Ethanol was selected as a solvent because of its environmental friendliness and high volatility to ensure rapid evaporation after spraying on the substrate. The schematic illustration of the fabrication of superhydrophobic coatings was shown in Figure 1a.…”