Issue 18, 2023

Oxidization enhances type I ROS generation of AIE-active zwitterionic photosensitizers for photodynamic killing of drug-resistant bacteria

Abstract

Type I photosensitizers (PSs) with an aggregation-induced emission (AIE) feature have received sustained attention for their excellent theranostic performance in the treatment of clinical diseases. However, the development of AIE-active type I PSs with strong reactive oxygen species (ROS) production capacity remains a challenge due to the lack of in-depth theoretical studies on the aggregate behavior of PSs and rational design strategies. Herein, we proposed a facile oxidization strategy to enhance the ROS generation efficiency of AIE-active type I PSs. Two AIE luminogens, MPD and its oxidized product MPD-O were synthesized. Compared with MPD, the zwitterionic MPD-O showed higher ROS generation efficiency. The introduction of electron-withdrawing oxygen atoms results in the formation of intermolecular hydrogen bonds in the molecular stacking of MPD-O, which endowed MPD-O with more tightly packed arrangement in the aggregate state. Theoretical calculations demonstrated that more accessible intersystem crossing (ISC) channels and larger spin–orbit coupling (SOC) constants provide further explanation for the superior ROS generation efficiency of MPD-O, which evidenced the effectiveness of enhancing the ROS production ability by the oxidization strategy. Moreover, DAPD-O, a cationic derivative of MPD-O, was further synthesized to improve the antibacterial activity of MPD-O, showing excellent photodynamic antibacterial performance against methicillin-resistant S. aureus both in vitro and in vivo. This work elucidates the mechanism of the oxidization strategy for enhancing the ROS production ability of PSs and offers a new guideline for the exploitation of AIE-active type I PSs.

Graphical abstract: Oxidization enhances type I ROS generation of AIE-active zwitterionic photosensitizers for photodynamic killing of drug-resistant bacteria

Supplementary files

Article information

Article type
Edge Article
Submitted
21 2 2023
Accepted
05 4 2023
First published
17 4 2023
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2023,14, 4863-4871

Oxidization enhances type I ROS generation of AIE-active zwitterionic photosensitizers for photodynamic killing of drug-resistant bacteria

J. Gong, L. Liu, C. Li, Y. He, J. Yu, Y. Zhang, L. Feng, G. Jiang, J. Wang and B. Z. Tang, Chem. Sci., 2023, 14, 4863 DOI: 10.1039/D3SC00980G

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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