Reactivity Differences Enable ROS for Selective Ablation of Bacteria

Abstract

An effective strategy to engineer selective photodynamic agents to surmount bacterial‐infected diseases, especially Gram‐positive bacteria remains a great challenge. Herein, we developed two examples of compounds for a proof‐of‐concept study where reactive differences in reactive oxygen species (ROS) can induce selective ablation of Gram‐positive bacteria. Sulfur‐replaced phenoxazinium (NBS‐N) mainly generates a superoxide anion radical capable of selectively killing Gram‐positive bacteria, while selenium‐substituted phenoxazinium (NBSe‐N) has a higher generation of singlet oxygen that can kill both Gram‐positive and Gram‐negative bacteria. This difference was further evidenced by bacterial fluorescence imaging and morphological changes. Moreover, NBS‐N can also successfully heal the Gram‐positive bacteria‐infected wounds in mice. We believe that such reactive differences may pave a general way to design selective photodynamic agents for ablating Gram‐positive bacteria‐infected diseases.

Polydopamine, harness of the antibacterial potentials-A review

“…Consequently, coating implants with antibiotic eluting materials seems to be one of the best options to prevent the infection and formation of biofilms [ [3] , [4] , [5] , [6] ]. One mechanism devised to overcome this challenge is the painting of surfaces of devices which can be said to be a traditional means [ [7] , [8] , [9] ]. However, this method may not be safe and reliable since any minimal scratch can still provide a surface for the bacteria to thrive.…”

Cationic AIE-active photosensitizers for highly efficient photodynamic eradication of drug-resistant bacteria

“…Pathogens are usually negatively charged, thus cationization also possibly provided these AIE PSs with the binding affinity. [44][45][46] Furthermore, nitrile-containing molecules could have a high binding affinity to the phospholipid membrane of the bacterial cell wall by hydrogen bonding interaction. 40 Considering the best ROS production with optimal HO À generation and the dual effect of bacterial binding ability of CN-TPAQ-PF 6 , CN-TPAQ and CN-TPAQ-PF 6 were selected for further bacterial imaging and PDT antibacterial research.…”

Unveiling upsurge of photogenerated ROS: control of intersystem crossing through tuning aggregation patterns

“…Organic photosensitizers (PSs) could convert substrates (oxygen, water, etc.) 1,2 into reactive oxygen species (ROS) upon illumination, providing advantages in the photon-triggered therapeutic strategy [3][4][5] and photocatalysis. 6 During this process, a critical step is that electrons in the excited singlet state (S 1 ) will undergo a fast spin-ip, achieving an excited triplet state (T 1 ) through intersystem crossing (ISC).…”