LaB₆ Nanoparticles For Cancer PTT/PDT Combination Therapy

With the advantages of non-toxic,harmless,no tissue damage,and no side effects,phototherapy of cancer has become a hot area in the scientific research community.There are currently two main types of phototherapy,photothermal therapy?PTT?and photodynamic therapy?PDT?.Undoubtedly,the combined effect of the two treatments will have a more ideal therapeutic effect.Therefore,it is meaningful to find a material that can achieve these two therapeutic effects.LaB₆ nanoparticle was chosen as light therapeutic agent in this study.The sample was characterized by transmission electron microscope,dynamic light scattering,X-ray diffraction,Raman spectra,X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy.The sample was determined to be LaB₆ nanocrystal with unevenly distributed size.The surface layer was oxidized,and the average hydration particle size was 340 nm.The UV-Vis-NIR absorption spectra indicated that the powder and dispersion of LaB₆ nanoparticles has strong light absorption.Under the excitation of NIR-880 nm?3.64 W/cm2?,125 ?g/m L LaB₆ dispersion could raise 24.8 ? in 10 min,meeting the temperature requirement of photothermal treatment of the tumor.At the same time,a large number of reactive oxygen species?ROS?were generated,which were suitable for photodynamic therapy.The theoretical calculation based on DFT confirmed that the strong near-infrared light absorption of LaB₆ nanoparticles is attributed to the local plasmonic resonance?LSPR?effect.The excellent photodynamic effect derived from the strong electron-giving ability.MTT results indicated that LaB₆ nanoparticles had no obvious cytotoxicity to Hep G2 cells.The result of in vitro phototherapy experiments showed an ideal therapeutic effect of LaB₆-mediated PTT/PDT combination therapy of tumor.In vivo treatment on Hep G2 tumor-bearing mice showed that LaB₆ nanoparticles could thoroughly destroy solid tumors and prevent their recurrence after irradiation of NIR-880 nm laser.After 14 days of treatment,the mice in the groups injected with LaB₆ dispersion showed no abnormal physical conditions and normal blood routine,indicating that the LaB₆ nanoparticles injected in situ didn't have acute biological toxicity.In summary,LaB₆ nanoparticles have strong near infrared absorption,which can produce both the photothermal effect and ROS under the excitation of NIR-880 nm laser,and have been successfully applied to cancer PTT/PDT synergistic therapy,providing a simple and effective reference for phototherapy of tumors.