Amphiphilic quaternary ammonium chitosans self-assemble onto bacterial and fungal biofilms and kill adherent microorganisms

Recent Progress in Bile Acid-Based Antimicrobials

“…Quaternary ammonium, called a permanent cation, generally contains a positive nitrogen atom and four attached groups. The quaternary ammonium cations could easily bind with the negatively charged compounds of the bacterial membrane followed by membrane lysis, showing a strong antibacterial effect. ,, By taking advantage of the hydrophilicity of the quaternary ammonium salt and the large hydrophobic surface of BA, the amphiphilic structure is reproduced to prepare antimicrobials.…”

“…Infections triggered by bacteria seriously threaten human health, leading to higher treatment costs and increased mortality. Although various antibacterial agents, such as antibiotics, have been substantially developed for treatment of bacterial infection, the majority of traditional antibacterial agents are becoming less efficient due to the abuse of antibiotics and the development of drug-resistant bacterial strains. − Besides, biofilms formed on a biomedical device surface provide a relatively stable environment for bacteria or fungi to proliferate, which require more doses of antibiotics to clear than planktonic microorganisms and further induce resistance to antibiotics. − Recently, nanomaterials possessing a photothermal effect , and antimicrobial surfaces − have also been developed for treatment of bacteria and eradication of biofilms, but it is still an arduous and urgent task to fight against drug-resistant microorganisms, including carbapenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa , vancomycin-resistant Enterococcus faecium , and methicillin-resistant Staphylococcus aureus on the WHO priority list. , …”

A simple method of simultaneously endowing paper or fluff pulp with both high softness or appropriate fluffing properties and antimicrobial properties

“…Then it hinders the bacteria from getting closer to achieve certain antibacterial effect. Besides, the AQAS contacts with the surface of bacteria, and the structure of bacteria cell membrane is destroyed, so that the bacteria die (Jung et al 2019), to achieve the purpose of sterilization. However, the softening effect can be attributed to: (1) the quaternary nitrogen positive ions combine with free hydroxyl groups on the surface of bers, reduce the formation of hydrogen bonds, weaken the bond between bers, decrease the static friction coe cient between bers, and then the surface of the bers became smoother, (2) long alkyl chains have a certain hydrophobicity, which reduces the formation of hydrogen bonds between bers and makes the structure of bers more loose.…”

Bio-Based Polymers with Antimicrobial Properties towards Sustainable Development

“…A different strategy was followed in a recent work, in which quaternized chitosan samples with alkyl chains were prepared by an external acid-free method [39]. In this approach, a quaternary ammonium molecule containing carboxylic acid was synthesized, which acted as a reactant for attachment onto the amino groups of chitosan via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/ N -hydroxysuccinimide (EDC/NHS) chemistry and also acted as an acid for the dissolution of chitosan.…”