Phototheranostics is a potential area for precision medicine, which has received increasing attention for antibacterial applications. Integrating all phototheranostic modalities in a single molecule and achieving precise spatial colocalization is a challenging task because of the complexity of energy dissipation and molecular design. Here, a type of quaternary amine functionalized aggregation-induced emission (AIE), AIEgen, was synthesized and used to produce singlet oxygen (1O2) and heat, which were used to eradicate the bacteria. With the introduction of the positive charge in AIEgen, AIE nanoparticles (AIE NPs) could selectively target bacteria. Notably, the AIE NPs displayed obvious antibacterial performance against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). The antibacterial rates of AIE NPs were as high as 99.9% and 99.8% for S. aureus and E. coli, respectively. Therefore, our results suggested the potential of AIE NPs acting as broad-spectrum antimicrobial materials, which provided a strategy for treating different microorganisms.

Although photothermal therapy (PTT) has thrived as a promising treatment for drug-resistant bacterial infections by avoiding the abuse of antibiotics, the remaining challenges that limit the treatment efficiency are the poor targeting properties of infected lesions and low penetration to the cell membrane of Gram-negative bacteria. Herein, we developed a biomimetic neutrophil-like aggregation-induced emission (AIE) nanorobot (CM@ AIE NPs) for precise inflammatory site homing and efficient PTT effects. Due to their surface-loaded neutrophil membranes, CM@AIE NPs can mimic the source cell and thus interact with immunomodulatory molecules that would otherwise target endogenous neutrophils. Coupled with the secondary near-infrared region absorption and excellent photothermal properties of AIE luminogens (AIEgens), precise localization, and treatment in inflammatory sites can be achieved, thereby minimizing damage to surrounding normal tissues. Moreover, CM@AIE NP-mediated PTT was stimulated in vivo by a 980 nm laser irradiation, which contributed to the extent of the therapeutic depth and limited the damage to skin tissues. The good biocompatibility and excellent in vitro and in vivo antibacterial effects prove that CM@AIE NPs can provide a strategy for broad-spectrum antibacterial applications.

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Although photothermal therapy is of significance in therapeutic strategies for fighting bacterial infection, the precise target of photothermal agents to bacterial sites is still a challenge. In this work, lipopolysaccharide (LPS) imprinted photothermal molecularly imprinted polymers (PMIP) were prepared for the efficient capture and elimination of Pseudomonas aeruginosa. The LPS derived from Pseudomonas aeruginosa was selected as a template due to its cis-diol structure, which can provide active sites to direct the boronate affinity-mediated synthesis of molecularly imprinted polymers. Polydopamine with good biocompatibility and photothermal effect was used as an imprinting matrix to achieve good photothermal function and imprinting efficiency. The combination of bacteria-imprinting with photothermal ability allowed PMIP to deactivate target bacteria with enhanced precision and efficiency. Taken together, our study offers a promising strategy to design synthetic materials for targeting and treating pathogens for various infectious diseases and expands the application of molecular imprinting technology in the field of antimicrobials.

Bacterial infections caused by pathogenic bacteria are extremely threatening to human health. Currently, the treatment of bacterial infections relies heavily on antibiotics, leading to a high incidence of antibiotic abuse. Bacterial resistance appeared along with the misuse of antibiotics that produced growing harm to human beings. Therefore, a cutting-edge strategy for treating bacterial infections is indeed needed. Here we prepared QCuRCDs@BMoS2 nanocomposites (QBs) for an efficient bacterial trapping and triple quaternary ammonium salt/photothermal/photodynamic bactericidal method. Copper-doped carbon quantum dots were first prepared by using a solvothermal method, modified with quaternary ammonium salts, and then combined with grafted MoS2 nanoflowers. The long alkyl chains of QBs and the sharp surface of MoS2 facilitate the destruction of bacterial structures, while the electrostatic adsorption binds closely to bacteria, shortening the bactericidal distance of the reactive oxygen species (ROS). Moreover, the excellent photothermal performance under 808 nm irradiation in the near-infrared (NIR) region and deep penetrating heat can accelerate oxidative stress and achieve a multisynergistic bactericidal purpose. Consequently, QBs with ideal antibacterial properties and inherent brightness hold great promise in the biomedical field.