pH Window for High Selectivity of Ionizable Antimicrobial Polymers toward Bacteria

Abstract

Antimicrobial polymers exhibit great potential for treating drug-resistant bacteria; however, designing antimicrobial polymers that can selectively kill bacteria and cause relatively low toxicity to normal tissues/cells remains a key challenge. Here, we report a pH window for ionizable polymers that exhibit high selectivity toward bacteria. Ionizable polymer PC6A showed the greatest selectivity (131.6) at pH 7.4, exhibiting low hemolytic activity and high antimicrobial activity against bacteria, whereas a very high or low protonation degree (PD) produced relatively low selectivity (≤35.6). Bactericidal mechanism of PC6A primarily comprised membrane lysis without inducing drug resistance even after consecutive incubation for 32 passages. Furthermore, PC6A demonstrated synergistic effects in combination with antibiotics at pH 7.4. Hence, this study provides a strategy for designing selective antimicrobial polymers.

Potential antibacterial and antioxidant inhibitory activities of Silybum marianum mediated biosynthesised He-Ne laser

“…According to Hanafi et al (2023) , the decline of gram (+) microbes is due to silybin’s interference with the production of proteins and RNA; based on the efficacy of the ethyl acetate extract in our investigation, which showed the presence of the flavonolignans silibinin, discovered by high-performance liquid chromatography, against gram (+) bacteria ( Hanafi et al, 2023 ). Geng et al (2023) describe the effects of polyphenols on gram-positive bacteria, either by preventing the activity of enzymes required for the bacterial cell to produce energy by altering the permeability of the cell or by preventing the synthesis of ARN ( Geng et al, 2023 ).…”