Niobium Carbide Mediated Photothermal Therapy For Antibacterial Treatment

Background and purposeBacterial infection is one of the diseases affecting human health,which causes about 10 million deaths every year.Antibiotics are commonly used for preventing bacterial infections,but the overuse of antibiotics have led to bacterial resistance.Photothermal therapy has many advantages such as excellent antibacterial properties,less side effects,low bacterial resistance and so on.Therefore,it is significance to find a biosafe photothermal material with high photothermal effect.NbC was selected as a research object to study its photothermal properties and antibacterial effects.Materials and Methods(1)Characterization of NbC nanoparticles: to obtain basic information about NbC,the sample was characterized by TEM,DLS,XRD,XPS,etc.(2)Photothermal properties of NbC nanoparticles: the optical absorption properties of NbC were tested by UV-Vis-NIR,and then the photothermal properties were studied in this part.(3)Vitro antibacterial effect of NbC nanoparticles: plate colony count method,live/dead staining,β-D-galactosidase activity test,SEM and other tests were used to clarify the antibacterial process and antibacterial mechanism of NbC.(4)Vivo antimicrobial therapy and biocompatibility: in this part,the NbC nanoparticles were used to treat infected wounds in mice to observe the antibacterial effect of NbC in vivo.Finally,the biocompatibility of NbC nanoparticles was evaluated by H&E staining and other methods.Results(1)Characterization of NbC: NbC samples are nano-scale particles with a size between 20-40 nm,which determined to be pure phase by XRD and XPS.(2)Photothermal performance of NbC nanoparticles: NbC nanoparticles have strong photothermal effect in the NIR region.(3)Antibacterial effect of NbC: plate colony count method shows that 500 μg/m L NbC nanoparticles solution have excellent antibacterial effect on E.coli and S.aureus.According to SEM and β-D-galactosidase analysis,the photothermal antibacterial effect of NbC nanoparticles induce bacteria death via cell membrane damage.(4)Vivo antimicrobial therapy and biocompatibility:NbC nanoparticles can effectively heal the infected wounds in mice via photothermal treatment.CCK-8 test,live/dead staining assay,hemolysis test and H&E staining images confirm that NbC is a biosafe material with low toxicity.ConclusionsIn our works,the size of the NbC sample is 20-40 nm in diameter.According to the experimental results,NbC has excellent photothermal effect.NbC nanoparticles under NIR-808 irradiation can effectively kill E.coli and S.aureus via photothermal treatment.It has been confirmed that the NbC mediated photothermal effect could promote infected wound healing in mice.More importantly,NbC is a biosafe material with low toxicity.