Biocidal activity of multifunctional cuprite-doped anion exchanger – Influence of bacteria type and medium composition

• Published in: The Science of the total environment 2023-09, Vol.891, p.164667-164667, Article 164667
• Main Authors: Jacukowicz-Sobala, Irena, Kociołek-Balawejder, Elżbieta, Stanisławska, Ewa, Seniuk, Alicja, Paluch, Emil, Wiglusz, Rafal J., Dworniczek, Ewa
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Anti-Infective Agents; Antimicrobial agent; Bacteria; Bacterial Infections; Copper - pharmacology; Cuprous oxide; Enterococcus faecalis; Humans; Hybrid ion exchanger; Microbial Sensitivity Tests; Polymers; Pseudomonas aeruginosa; Water disinfection
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.164667

The study presents unconventional, bifunctional, heterogeneous antimicrobial agents – Cu2O-loaded anion exchangers. The synergetic effect of a cuprous oxide deposit and polymeric support with trimethyl ammonium groups was studied against the reference strains of Enterococcus faecalis ATCC 29212 and Pseudomonas aeruginosa ATCC 27853. Biological testing (minimum bactericidal concentration, MBC), time- and dose-dependent bactericidal effect (under different conditions – medium composition and static/dynamic culture) demonstrated promising antimicrobial activity and confirmed its multimode character. The standard values of MBC, for all studied hybrid polymers and bacteria, were similar (64–128 mg/mL). However, depending on the medium conditions, due to the copper release into the bulk solution, bacteria were actively killed even at much lower doses of the hybrid polymer (25 mg/mL) and low Cu(II) concentrations in solution (0.01 mg/L). Simultaneously, confocal microscopic studies confirmed the effective inhibition of bacterial adhesion and biofilm formation on their surface. The studies conducted under different conditions showed also the influence of the structure and physical properties of studied materials on the biocidal efficacy and an antimicrobial action mechanism was proposed that could be significantly affected by electrostatic interactions and copper release to the solution. Although the antibacterial activity was also dependent on various strategies of bacterial cell resistance to heavy metals present in the aqueous medium, the studied hybrid polymers are versatile and efficient biocidal agents against bacteria of both types, Gram-positive and Gram-negative. Therefore, they can be a convenient alternative for point-of-use water disinfection systems providing water quality in medical devices such as dental units, spa equipment, and aesthetic devices used in the cosmetic sector. [Display omitted] •Anion exchangers with a Cu2O deposit as innovative composite antimicrobials•Synergy between Cu2O fine particles and the –CH2N(CH3)3+ groups of host materials•Successful inactivation of bacteria with MBCs of up to 64 and 128 mg/mL•Possibility of rapid inactivation of both Gram-positive and Gram-negative bacteria