Water-soluble PANI:PSS designed for spontaneous non-disruptive membrane penetration and direct intracellular photothermal damage on bacteria

Abstract

The major challenge in the field of antibacterial agents is to overcome the low-permeability of bacteria cell membranes that protects the cells against diverse drugs. In this work, water-soluble polyaniline (PANI)-poly (p-styrenesulfonic acid) (PSS) (PANI:PSS) is found to spontaneously penetrate bacteria cellular membranes in a non-disruptive way, leaving no evidence of membrane poration/disturbance or cell death, thus avoiding side effects caused by cationic ammonia groups in traditional ammonia-containing antibacterial agents. For aqueous synthesis, which is important for biocompatibility, the polymer is synthesized via an enzyme-mimetic route relying on the catalysis of a nanozyme. Owing to its fluorescent properties, the localization of as-prepared PANI:PSS is determined by the confocal microscope, and the results confirm its rapid entry into bacteria. Under 808 nm near-infrared (NIR) irradiation, the internalized PANI:PSS generates local hyperthermia and destroys bacteria highly efficiently from inside the cells due to its excellent photothermal effects. Staphylococcus aureus ( S. aureus ), M ethicillin-resistant Staphylococcus aureus ( MRSA ) and Escherichia coli ( E. coli ) could be effectively eliminated as well as the corresponding bacterial biofilms. Results of in vivo antibacterial experiments demonstrate excellent antibacterial activities of the water-soluble PANI:PSS without side effects. Therefore, the prepared water-soluble polymer in this study has great potential in the treatment of various bacterial infections.

Cationic porphyrin-based nanoparticles for photodynamic inactivation and identification of bacteria strains

“…Live bacteria with intact cell membranes emitted green fluorescence, while dead bacteria with damaged cell membranes emitted red fluorescence. 47 As shown in Fig. 6, the biofilms cultured with PBS with/without laser irradiation exhibit strong green fluorescence and negligible red fluorescence.…”

A NIR-II light-modulated injectable self-healing hydrogel for synergistic photothermal/chemodynamic/chemo-therapy of melanoma and wound healing promotion

“…In contrast, the number of E. coli and S. aureus colonies decreased remarkably in the GG@PANI-borax group, especially for S. aureus , which could be ascribed to the intrinsic antibacterial property of the PANI component, and the distinct bactericidal effect against S. aureus may result from the specific interaction of PANI with lipoteichoic acid molecules in the cell walls of Gram-positive bacteria. 54 More importantly, only very few E. coli and almost no S. aureus left could be seen after co-culturing with the GG@PANI(Fe)-borax hydrogel, and the antibacterial efficiency of the GG@PANI(Fe)-borax hydrogel was almost up to 100% against both E. coli and S. aureus . This excellent antibacterial activity is mainly assigned to the combined effect of the intrinsic antibiotic activity of PANI and iron ions.…”

Radio Frequency Heating of Washable Conductive Textiles for Bacteria and Virus Inactivation

“…MSRA is a bacterium that is resistant to several antibiotics, making it difficult to treat. However, applied heat can lead to bacterial cell damage and bacterial inactivation. − To demonstrate inactivation of the bacteria, c-fabric was first exposed to the bacteria and RF heated (with a target temperature of 80 °C). Figure b is a representative result comparing the reduction of bacterial colony forming units (CFU) via RF heating on MRSA with and without our RF susceptor (c-fabric).…”