Multivalent and synergistic chitosan oligosaccharide-Ag nanocomposites for therapy of bacterial infection

• Published in: Scientific reports 2020-06, Vol.10 (1), p.10011, Article 10011
• Main Authors: Mei, Lin, Xu, Zhenlong, Shi, Yanmei, Lin, Chunlei, Jiao, Shuyan, Zhang, Lijun, Li, Pengxu
• Format: Article
• Language: English
• Subjects: 639/301/54/990; 639/638/298/54/990; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Antibacterial activity; Bacteria; Bacterial diseases; Bacterial infections; Bacterial Infections - drug therapy; Chitosan; Chitosan - chemistry; Chitosan - pharmacology; Chitosan - therapeutic use; Cytoplasm; Cytotoxicity; Escherichia coli - drug effects; Gram-negative bacteria; Humanities and Social Sciences; Humans; Magnesium; Membrane permeability; Metal Nanoparticles - chemistry; Metal Nanoparticles - therapeutic use; multidisciplinary; Nanocomposites; Nanocomposites - chemistry; Nanocomposites - therapeutic use; Nanoparticles; Oligosaccharides; Oligosaccharides - chemistry; Oligosaccharides - pharmacology; Oligosaccharides - therapeutic use; Science; Science (multidisciplinary); Silver; Silver - chemistry; Staphylococcus aureus - drug effects; Wound healing
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-67139-7

Chitosan oligosaccharide functionalized silver nanoparticles with synergistic bacterial activity were constructed as a multivalent inhibitor of bacteria. Placing the chitosan oligosaccharide on silver nanoparticles can dramatically enhance the adsorption to the bacterial membrane via multivalent binding. The multicomponent nanostructures can cooperate synergistically against gram-positive and gram-negative bacteria. The antibacterial activity was increased via orthogonal array design to optimize the synthesis condition. The synergistic bacterial activity was confirmed by fractional inhibitory concentration and zone of inhibition test. Through studies of antimicrobial action mechanism, it was found that the nanocomposites interacted with the bacteria by binding to Mg 2+ ions of the bacterial surface. Then, the nanocomposites disrupted bacterial membrane by increasing the permeability of the outer membrane, resulting in leakage of cytoplasm. This strategy of chitosan oligosaccharide modification can increase the antibacterial activity of silver nanoparticles and accelerate wound healing at the same time. The nanomaterial without cytotoxicity has promising applications in bacteria-infected wound healing therapy.