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While the ongoing COVID‐19 pandemic affirms an urgent global need for effective vaccines as second and third infection waves are spreading worldwide and generating new mutant virus strains, it has also revealed the importance of mitigating the transmission of SARS‐CoV‐2 through the introduction of restrictive social practices. Here, it is demonstrated that an architecturally‐ and chemically‐diverse family of nanostructured anionic polymers yield a rapid and continuous disinfecting alternative to inactivate coronaviruses and prevent their transmission from contact with contaminated surfaces. Operating on a dramatic pH‐drop mechanism along the polymer/pathogen interface, polymers of this archetype inactivate the SARS‐CoV‐2 virus, as well as a human coronavirus surrogate (HCoV‐229E), to the minimum detection limit within minutes. Application of these anionic polymers to frequently touched surfaces in medical, educational, and public‐transportation facilities, or personal protection equipment, can provide rapid and repetitive protection without detrimental health or environmental complications. [ABSTRACT FROM AUTHOR]

The prolonged survival of microbes on surfaces in high-traffic/high-contact environments drives the need for a more consistent and passive form of surface sterilization, with the goal of minimizing pathogen transmission. Here, we developed self-disinfecting materials through the covalent attachment of a porphyrin-based photosensitizer (PS) to nanofibrillated cellulose (NFC) and paper (Pap), imparting antimicrobial activity to these renewable scaffolds via photodynamically generated singlet oxygen. The facile covalent attachment of the free-base 5-(4-aminophenyl)-10,15,20-tris-(4-N-methylpyridinium)porphyrin (A3B3+) and metallated [5-(4-aminophenyl)-10,15,20-tris-(4-N-methylpyridinium)porphyrinato]zinc(ii) (Zn-A3B3+) photosensitizers was accomplished by aqueous cyanuric chloride coupling, avoiding the use of organic solvents of previous coupling strategies, while preventing PS leaching that is an issue with non-covalent PS incorportation strategies. Materials characterization and the degree of photosensitizer loading were determined by FTIR, elemental and TGA analyses, and UV-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS). The antimicrobial potencies of the resultant PS-NFC and PS-Pap materials were evaluated against four strains of bacteria recognized by the World Health Organization as either critical or high priority pathogens: Gram-positive strains methicillin-resistant S. aureus (MRSA; ATCC-44) and vancomycin-resistant E. faecium (VRE; ATCC-2320), and Gram-negative strains multidrug-resistant A. baumannii (MDRAB; ATCC-1605) and NDM-1 positive K. pneumoniae (KP; ATCC-2146). Our results demonstrated broad photodynamic inactivation of all strains studied upon illumination (30 min; 65 ± 5 mW cm−2; 400–700 nm) by a minimum of 99.999%. Antiviral studies against two enveloped viruses, dengue-1 (DENV) and vesicular stomatitis virus (VSV), revealed complete inactivation by both materials. Taken together, the results demonstrate the potential for photoactive NFC as the basis for sustainable broad spectrum anti-infective materials. [ABSTRACT FROM AUTHOR]

Highly persistent, drug-resistant and transmissible healthcare pathogens such as Clostridioides difficile (C. difficile) and Candida auris (C. auris) are responsible for causing antibiotic-associated fatal diarrhea and invasive candidiasis, respectively. In this study, we demonstrate that these potentially lethal gastrointestinal microbes can be rapidly inactivated on the solid surface of a self-disinfecting anionic block polymer that inherently generates a water surface layer that is highly acidic (pH < 1) upon hydration. Due to thermodynamic incompatibility between its chemical sequences, the polymer spontaneously self-organizes into a nanostructure that enables proton migration from the interior of a film to the surface via contiguous nanoscale hydrophilic channels, as discerned here by scanning electron and atomic force microscopies, as well as X-ray photoelectron spectroscopy. Here, we report that two strains of C. difficile in the vegetative state and two species of Candida, Candida albicans (C. albicans) and C. auris, are, in most cases, inactivated to the limit of minimum detection. Corresponding electron and optical microscopy images reveal that, upon exposure to the hydrated polymer, the outer microbial membranes display evidence of damage and intracellular material is expelled. Combined with our previous studies of rapid bacterial and viral inactivation, these antimicrobial results are highly encouraging and, if translatable to clinical conditions in the form of self-standing polymer films or coatings, are expected to benefit the welfare of patients in healthcare facilities by continuously preventing the spread of such potentially dangerous microbes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)

The dual threats posed by the COVID-19 pandemic and hospital-acquired infections (HAIs) have emphasized the urgent need for self-disinfecting materials for infection control. Despite their highly potent antimicrobial activity, the adoption of photoactive materials to reduce infection transmission in hospitals and related healthcare facilities has been severely hampered by the lack of scalable and cost-effective manufacturing, in which case high-volume production methods for fabricating aPDI-based materials are needed. To address this issue here, we examined the antimicrobial efficacy of a simple bicomponent spray coating composed of the commercially-available UV-photocrosslinkable polymer N -methyl-4(4'-formyl-styryl)pyridinium methosulfate acetal poly(vinyl alcohol) (SbQ-PVA) and one of three aPDI photosensitizers (PSs): zinc-tetra(4- N -methylpyridyl)porphine (ZnTMPyP 4+ ), methylene blue (MB), and Rose Bengal (RB). We applied these photodynamic coatings, collectively termed SbQ-PVA/PS, to a variety of commercially available materials. Scanning electron microscopy (SEM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) confirmed the successful application of the coatings, while inductively coupled plasma-optical emission spectroscopy (ICP-OES) revealed a photosensitizer loading of 0.09-0.78 nmol PS/mg material. The antimicrobial efficacy of the coated materials was evaluated against methicillin-susceptible Staphylococcus aureus ATCC-29213 and human coronavirus strain HCoV-229E. Upon illumination with visible light (60 min, 400-700 nm, 65 ± 5 mW/cm 2 ), the coated materials inactivated S. aureus by 97-99.999% and HCoV-229E by 92-99.999%, depending on the material and PS employed. Photobleaching studies employing HCoV-229E demonstrated detection limit inactivation (99.999%) even after exposure for 4 weeks to indoor ambient room lighting. Taken together, these results demonstrate the potential for photodynamic SbQ-PVA/PS coatings to be universally applied to a wide range of materials for effectively reducing pathogen transmission., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Ghareeb, Peddinti, Kisthardt, Scholle, Spontak and Ghiladi.)

To combat the global threat posed by surface-adhering pathogens that are becoming increasingly drug-resistant, we explore the anti-infective efficacy of bulk thermoplastic elastomer films containing ∼1 wt % zinc-tetra(4- N-methylpyridyl)porphine (ZnTMPyP 4+ ), a photoactive antimicrobial that utilizes visible light to generate singlet oxygen. This photodynamic polymer is capable of inactivating five bacterial strains and two viruses with at least 99.89% and 99.95% success, respectively, after exposure to noncoherent light for 60 min. Unlike other anti-infective methodologies commonly requiring oxidizing chemicals, carcinogenic radiation, or toxic nanoparticles, our approach is nonspecific and safe/nontoxic, and sustainably relies on the availability of just oxygen and visible light.