A Tumor Microenvironment Response Reagent DFS@HKUST-1 For Photoacoustic Imaging Guiding Multi-methods Combined Therapy

For the treatment of cancer,the combined treatment of multiple treatment methods has less toxicity and better therapeutic effects in tumor treatment than monotherapy.Therefore,multi-methods combined therapy has a broader development space in the treatment of cancer.However,the development of simple and effective strategies to build multifunctional nanoplatforms are still a major problem to be solved.In this paper,based on the characteristics of tumor microenvironment,mild acidic environment and overexpression of H₂O₂,we constructed a tumor microenvironment response diagnostic and therapeutic nanoreagent DFS@HKUST-1guided by photoacoustic imaging.It can be applied in the multi-methods combined treatment of breast cancer by combining photothermal therapy,chemodynamic therapy and in situ chemotherapy.Specific experimental contents are as follows:First of all,we synthesized the uniform size of HKUST-1 and encapsulated disulfiram(DSF)into HKUST-1 through physical adsorption,and used PVP to improve water solubility,and finally formed DSF@HKUST-1 nanoparticles.We have proved the successfully synthesis of DSF@HKUST-1 nanoparticles by X-ray powder diffraction and other methods.Subsequently,we investigated the photothermal heating performance and photoacoustic imaging effect of DSF@HKUST-1nanoparticles at 808 nm.The results showed that the material had a good photothermal heating effect and a high photothermal conversion efficiency(?=26.69%),which provided a possibility for photoacoustic(PA)imaging guided photothermal therapy(PTT).Furthermore,the dissociated Cu²⁺of DSF@HKUST-1nanoparticles in PBS buffer solution at p H 6.5 can react with H₂O₂ to produce hydroxyl radical(·OH).At the same time,the released Cu²⁺and DSF can be in situ synthesis of Cu ET.Then,we evaluated the good biocompatibility of DSF@HKUST-1nanoparticles by hemolysis assay,and investigated the production of ROS at the cell level and the efficacy of multi-methods combined therapy by cell assay.First of all,we evaluated the different concentration of DSF@HKUST-1 nanoparticles toxicity to normal cells and breast cancer cells in mice,the results showed that DSF@HKUST-1nanoparticles have no obvious side effects on the normal cells,while the breast cancer cells in mice showed the concentration dependence of toxicity,which was caused by different p H values in normal cells and breast cancer cells.Then,by laser confocal experiments and flow cytometry,it was proved that DSF@HKUST-1 nanoparticles can make 4T1 cells produce ROS in the presence of H₂O₂.Finally,the laser confocal living and dead cell assay and MTT assay proved that DSF@HKUST-1 had the strongest lethal effect on 4T1 cells under the multi-methods'combination of photothermal therapy,chemodynamic therapy and in situ chemotherapy.Finally,we carried out in vivo treatment experiments.First,in vivo photoacoustic imaging experiments showed that the maximum enrichment time of DFS@HKUST-1 nanoparticles in the tumor site was 2 hours.According to this time point,we performed photothermal therapy and photothermal imaging experiments on mice at 2 hours after DFS@HKUST-1 nanoparticles were injected into the tail vein.According to the experimental data,mice in the DSF@HKUST-1 group can kill tumor cells better under the condition of laser irradiation.Finally,we evaluated the therapeutic efficacy of DSF@HKUST-1 in vivo level through long-term monitoring.The experimental results showed that DSF@HKUST-1 combined with photothermal therapy,chemodynamic therapy and in situ chemotherapy under the guidance of photoacoustic imaging had a significant tumor inhibition effect,and the tumor inhibition rate was as high as 98%under 20 days monitoring.In addition,the analysis of biochemical indexes and important tissue sections showed that DFS@HKUST-1nanoparticles had no obvious damage to the important organs of mice,which indicated that the material had negligible toxic and good biocompatibility in vivo.In conclusion,the photoacoustic imaging guided intelligent response reagent for tumor microenvironment DFS@HKUST-1 nanoparticles'multi-modal combined treatment method showed great potential in enhancing tumor specificity and therapeutic efficacy.