posted on 2020-03-13, 20:03authored byXiaoyan Ju, Jun Chen, Mengxue Zhou, Meng Zhu, Zhuang Li, Sijia Gao, Jinzhao Ou, Dandan Xu, Man Wu, Shidong Jiang, Yi Hu, Ye Tian, Zhongwei Niu
Pseudomonas aeruginosa (P. aeruginosa)
biofilms are associated with a wide range of infections, from chronic
tissue diseases to implanted medical devices. In a biofilm, the extracellular
polymeric substance (EPS) causes an inhibited penetration of antibacterial
agents, leading to a 100–1000 times tolerance of the bacteria.
In view of the water-filled channels in biofilms and the highly negative
charge of EPS, we design a chitosan-polyethylene glycol-peptide conjugate
(CS-PEG-LK13) in this study. The CS-PEG-LK13 prefers a neutrally charged assembly at a size of ∼100 nm
in aqueous environment, while undergoes disassembly to expose the
α-helical peptide at the bacterial cell membrane. This behavior
provides CS-PEG-LK13 superiorities in both penetrating
the biofilms and inactivating the bacteria. At a concentration of
8 times the minimum inhibitory concentration, CS-PEG-LK13 has a much higher antibacterial efficiency (72.70%) than LK13 peptide (15.24%) and tobramycin (33.57%) in an in vitro P. aeruginosa biofilm. Moreover, CS-PEG-LK13 behaves
comparable capability of combating an implanted P. aeruginosa biofilm to highly excess tobramycin. This work has implications
for the design of new antibacterial agents in biofilm combating.