Pathogenic bacteria infection is a serious threat to human public health due to the high morbidity and mortality rates. Nano delivery system for delivering antibiotics provides an alternative option to improve the efficiency compared to conventional therapeutic agents. In addition to the drug loading capacity of nanocarriers, which is typically around 10%, further lowers the drug dose that pathological bacteria are exposed to. Moreover, nanocarriers that are not eliminated from the body may cause side effects. These limitations have motivated the development of self-delivery systems that are formed by the self-assembly of different therapeutic agents. In this study, a vehicle-free antimicrobial polymer polyhexamethylene biguanide (PHMB, with bactericidal and anti-biofilm functions) hybrid gold nanoparticle (Au NPs, with photothermal therapy (PTT)) platform (PHMB@Au NPs) is developed. This platform exhibits an excellent synergistic effect to enhance the photothermal bactericidal effect for Staphylococcus aureus under near-infrared irradiation. Furthermore, the results showed that PHMB@Au NPs inhibit the formation of biofilms, quickly remove bacteria to promote wound healing through PTT in infection model in vivo, and even mediate the transition of macrophages from M1 to M2 type, and accelerate tissue angiogenesis. PHMB@Au NPs will have promising value as highly effective antimicrobial agents for patient management.
Ultrasound (US)‐mediated sonodynamic therapy (SDT) has the advantages of non‐invasiveness and deep tissue penetration. Nanosystems are prominently used in sonosensitization; however, most nano‐sonosensitizers have a low reactive oxygen species (ROS) yield, thus restraining the application of SDT. Sodium molybdenum bronze nanoparticles (SMB NPs) with rich oxygen vacancies are developed and interlayer gaps of molybdenum trioxide nanobelts are expanded. Owing to the increased oxygen vacancy density and wide interlayer gap‐induced narrower band gap of SMB NPs, the electrons (e–) and holes (h+) generated by US are separated more rapidly, and oxygen vacancies prevent electrons–holes recombination under US irradiation. SMB NPs exhibit a second near‐infrared (NIR‐II) photothermal effect to promote the generation of ROS by the sonosensitizer. The SMB NPs system is successfully realized to eliminate Staphylococcus aureus (S. aureus) and dissipate biofilm. Therefore, multimodal therapy using SMB NPs serves as an effective and promising regimen for deep‐seated bacterial infections. The newly developed Mo‐based sonosensitizer is presented for the first time to demonstrate excellent antimicrobial activity through hyperthermia‐promoting SDT therapeutics. This work proposes a novel strategy in the field of NIR‐II photo‐amplified SDT with Mo‐based materials for bacterial eradication and other important biomedical applications.
Zinc/Zn(II) is an essential trace element for humans and acts as an important substance that maintains the normal growth, development, and metabolism of the body. Excess or deficient Zn(II) can cause abnormal metabolism in the human body, leading to a series of diseases. Moreover, biosystems have complex homeostasis systems, especially harsh pH (OH − ) environments. Thus, investigating the variation in the levels of Zn(II) and OH − is extremely important in clinical, medical, and environmental testing. Nevertheless, the lack of practical and convenient fluorescence imaging tools limits the tracing of Zn(II) and OH − in biosystems. In this work, a well-designed dual-channel fluorescent signal response chemosensor (DACH-fhba) was assembled for selective sensing of Zn(II) and OH − in the biosystem using a fluorescence turn-on strategy. On encountering Zn(II), the chemosensor emitted a blue fluorescence signal (455 nm). Meanwhile, the bright green fluorescence signal (530 nm) increased with OH − addition simultaneously. With the blue/green dual fluorescence response of DACH-fhba, the sensor exhibited high stability and reversibility. Notably, the bioimaging revealed that DACH-fhba successfully tracked Zn(II) and OH − in live cells, larval zebrafish, and plants. Further results implied that DACH-fhba can be used to achieve visual detection of Zn(II) and OH − in organisms. Altogether, this work is conducive to the monitoring of Zn(II) and OH − in organisms and promotes the understanding of the function of Zn(II) and OH − in biosystems.
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