Visualization of Antimicrobial-Induced Bacterial Membrane Disruption with a Bicolor AIEgen

Abstract

Gram-negative bacteria are difficult to kill due to their complex cell envelope, including the outer membrane (OM) and cytoplasmic membrane (CM). To monitor the membranolytic action of antimicrobials on Gram-negative bacteria would facilitate the development of effective antimicrobials. In this paper, an aggregation-induced emission luminogen (AIEgen) with microenvironment-sensitive properties was employed to indicate the interaction of antimicrobials with the OM and CM of Gram-negative bacteria. The damaged extent of OM and CM caused by antimicrobials with the change of dosage and incubation time can be visually captured based on the variation of two emission colors of IQ-Cm responding to OM-defective (green) and CM-disruptive bacteria (orange). Meanwhile, the activity assessment of antimicrobials can be easily realized within 1~2 h based on the distinct response of IQ-Cm to live and dead E. coli, which is much faster than the agar plate culture. This probe may shed light on the understanding of the interaction between the membrane-active antimicrobials and cell envelope of Gram-negative bacteria and contribute to the future development of antimicrobials.

AIE‐Active Glycomimetics Triggered Bacterial Agglutination and Membrane‐Intercalating toward Efficient Photodynamic Antiseptic

“…This means that TPyGal aggregates can kill most P. aeruginosa with short irradiation time, based on that PI selectively stains dead bacteria with destroyed cell membrane. [ 22 ] As further confirmed by the antimicrobial results of Figure S17 (Supporting Information), the killing activity of TPyGal aggregates reaches 50% with 1 min of irradiation and is boosted to 92% at 10 min and ≈100% at 20 min. Collectively, with agglutination and further membrane intercalation functions, TPyGal aggregates possess high potency of PDT killing P. aeruginosa .…”

A Review on Physical, Chemical and Optical Properties of Liquid Crystal

“…According to the Onsager theory, the molecular polarizability as well as the permanent electrical dipole moment are two characteristics of molecules that are related to the dielectric constant. The polarizability must be considered as a tensor with all main values in the case of nematic LCs, and an angle must be included to define the location of to specify the location of the permanent dipole moment in relation to the molecule's long axis (Zhou, 2022).…”

Self‐reporting fluorescence deciphers the antibacterial nature of cationic amphiphiles: Monomer or aggregate?

“…[36,37] These features make AIEgens an excellent indicator for in situ identification of the aggregated and monomeric states of amphiphiles. In combination with the different microenvironments of amphiphile monomers, amphiphile aggregates, and bacteria, [23,38] it is reasonable to obtain clearly distinguishable fluorescence signals by rationally incorporating the AIE attribute into the cationic amphiphiles.…”