Synthesis, Characterization, and Antimicrobial Efficacy of Photomicrobicidal Cellulose Paper

Toward our goal of scalable, antimicrobial materials based on photodynamic inactivation, paper sheets comprised of photosensitizer-conjugated cellulose fibers were prepared using porphyrin and BODIPY photosensitizers, and characterized by spectroscopic (infrared, UV–vis diffuse reflectance, inductively coupled plasma optical emission) and physical (gel permeation chromatography, elemental, and thermal gravimetric analyses) methods. Antibacterial efficacy was evaluated against Staphylococcus aureus (ATCC-2913), vancomycin-resistant Enterococcus faecium (ATCC-2320), Acinetobacter baumannii (ATCC-19606), Pseudomonas aeruginosa (ATCC-9027), and Klebsiella pneumoniae (ATCC-2146). Our best results were achieved with a cationic porphyrin–paper conjugate, <b>Por</b>^<b>(+)</b>-paper, with inactivation upon illumination (30 min, 65 ± 5 mW/cm², 400–700 nm) of all bacterial strains studied by 99.99+% (4 log units), regardless of taxonomic classification. <b>Por</b>^<b>(+)</b>-paper also inactivated dengue-1 virus (>99.995%), influenza A (∼99.5%), and human adenovirus-5 (∼99%). These results demonstrate the potential of cellulose materials to serve as scalable scaffolds for anti-infective or self-sterilizing materials against both bacteria and viruses when employing a photodynamic inactivation mode of action