| The emergence of drug-resistant bacteria forces people to increase the use of antibiotics,increase the adverse reactions of drugs to the human body,and even cause changes in the human body posing new challenges and threats to human health.Eventually,humans will face serious infections and go to a situation where no medicine is available.Therefore,the development of new antibacterial drugs is imminent.Nanomaterials have great application potential in the field of bacteriostasis.The use of their enzyme-like properties and near-infrared absorption properties for joint bacteriostasis is currently attracting wide attention.It has become a trend to use their enzyme-like properties and near-infrared absorption properties for joint antibacterial.Oxygen defects are easily formed on the surface of transition metal oxides,which can promote nanoenzyme redox reactions.Mo-based oxides have variable valence due to their single-electron instability.This lays the foundation for the realization of enzyme activity and enhanced near-infrared absorption.The material has low toxicity and is a material of research significance.Therefore,it is necessary to develop high-efficiency,low-toxicity,and economical Mo-based transition metal oxide nanomaterials to tap their potential in antibacterial.In this paper,molybdenum oxide nanowires(Mo OxNWs)and nanodots(Mo O3-xNDS)nanozymes were prepared by a one-step method,and their antibacterial properties were studied.The specific contents mainly include the following aspects:1.MoOxNWs were synthesized by one-pot hydrothermal method using Mo Cl3powder as the molybdenum precursor and water as the solvent.The nanowires have regular morphology and have both photothermal and photodynamic properties under the excitation of a single wavelength(808 nm)near-infrared light source.Photodynamic therapy(PDT)and photothermal therapy(PTT)have excellent antibacterial properties against ESBL-producing E.coli and methicillin-resistant Staphylococcus aureus(MRSA)that produce extended-spectrum?-lactamase In vivo wound healing experiments further confirmed the high antibacterial properties,good biocompatibility and application potential of the Mo OxNWs synergistic antibacterial system.2.Although the combination of PDT and PTT can effectively inhibit drug-resistant bacteria,the antibacterial effect is limited by near-infrared light.In order to overcome the limitations of single-path antibacterial,we adopted the same synthetic method and collected the supernatant to obtain Mo O3-xNDS with oxygen vacancies.In addition to the photothermal and photodynamic properties,the nanodots have a smaller size than nanowires after cutting and expose more active sites,so they also have excellent enzyme-like properties.Studies have shown that Mo O3-xNDS has peroxidase properties in the presence of H2O2,and its peroxidase activity can further induce exogenous H2O2to produce·OH.Under 808 nm near-infrared irradiation,the combined photodynamic,photothermal and peroxidase-like enzyme activity triple therapy synergistically inhibits bacteria.Therein,photodynamic and photothermal therapies can be both achieved under the excitation of a single wavelength light source(808 nm).Both the photodynamic and nanozyme activity can result in the generation of reactive oxygen species(ROS)to reach the broad-spectrum sterilization.Interestingly,the photothermal effect can regulate the Mo O3-xNDs to their optimum enzymatic temperature(50°C)to give sufficient ROS generation in low concentration of H2O2(100?M).Mo O3-xNDs nanozymes show excellent antibacterial effects on MRSA and ESBL-producing E.coli under near-infrared light.Animal experiments further show that the designed antibacterial measures can effectively promote the healing of wounds infected with MRSA in the living body. |
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