Adding Flying Wings: Butterfly-Shaped NIR-II AIEgens with Multiple Molecular Rotors for Photothermal Combating of Bacterial Biofilms

Abstract

The ever-increasing threats of multidrug-resistant bacteria and their biofilm-associated infections have bred a desperate demand for alternative remedies to combat them. Near-infrared (NIR)-absorbing photothermal agent (PTAs)mediated photothermal therapy (PTT) is particularly attractive for biofilm ablation thanks to its superiorities of noninvasive intervention, satisfactory antibacterial efficiency, and less likelihood to develop resistance. Herein, three butterfly-shaped aggregationinduced emission luminogens (AIEgens) with balanced nonradiative decay (for conducting PTT) and radiative decay (for supplying fluorescence in the NIR-II optical window) are rationally designed for imaging-assisted photothermal obliteration of bacterial biofilms. After being encapsulated into cationic liposomes, AIEgens-fabricated nanoparticles can eradicate a wide spectrum of biofilms formed by Gram-positive bacteria (methicillin-resistant Staphylococcus aureus and Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) upon an 808 nm laser irradiation. In vivo experiments firmly demonstrate that the NIR-II AIE liposomes with excellent biocompatibility perform well in both the P. aeruginosa biofilm-induced keratitis mouse model and the MSRA biofilm-induced skin infection mouse model.

Recent advances in combatting bacterial infections via well-designed metallacycles/metallacages

“…9,10 Therefore, it is imperative to develop more effective drugs to combat the growing problem of bacterial infections. In recent years, researchers have made great efforts and achieved breakthroughs in designing new antibacterial agents, such as metal organic molecules, [11][12][13][14] MOFs, 15,16 COFs, 17,18 and nanomaterials. [19][20][21] Furthermore, new mechanisms of antibacterial action, such as photodynamic inactivation, have been developed.…”

A universal strategy to enhance photothermal conversion efficiency by regulating the molecular aggregation states for safe photothermal therapy of bacterial infections

“…8–11 In view of the non-invasive attribute, high selectivity, deep tissue penetration, less drug resistance, and broad-spectrum antibacterial properties, near-infrared (NIR)-based photothermal therapy (PTT) has emerged as a pivotal approach for effectively combating drug-resistant bacterial infections. 12–15 Nevertheless, conventional organic photothermal agents (PTAs) often exhibit low photothermal conversion efficiencies (PCEs), necessitating an increase in either PTA concentrations or laser power densities to achieve ideal therapeutic outcomes. 16–19 However, increasing PTA concentrations results in persistent dark toxicity, while surpassing the maximum permissible exposure (MPE) has detrimental effects on healthy tissues.…”

Activated aggregation‐induced emission therapeutics agents for triggering regulated cell death

“…Furthermore, depending on the various forms of energy release, phototherapy is categorized into two main types: photodynamic therapy (PDT) [11][12][13] and photothermal therapy (PTT). [14][15][16][17] However, the effectiveness of phototherapy in the treatment of deep-seated tumors is limited due to the constrained penetration of excitation light into deep tissues. To overcome this challenge, sonodynamic therapy (SDT) can be employed, which uses ultrasound as the excitation source.…”