Two Functional Nano-materials Based On CuS And Their Anti-tumor Properties

In recent years,the combination therapy of nanomaterials as multimodal therapeutics has been confirmed to be a promising approach to cancer treatment.The synthesis of nanocomposites and nanobased drugs with multimode imaging guidance is an urgent problem.The new multifunctional nanocomposite integrates multimodal imaging into a nanosystem,including computed tomography,magnetic resonance imaging and upconversion fluorescence imaging,and combined it with photothermal/photodynamic/chemotherapy.CuS nanoparticles have the advantages of low toxicity,low cost,easy preparation,higher photothermal conversion efficiency and higher thermal stability.Therefore,the research of this paperis based on CuS nanoparticles,combining multimodal imaging and treatment to consider the synergistic treatment efficiency.The main contents of this paper are summarized as follows:The electrostatic adsorption method is used to combine the CuS nanoparticles of photothermal agent,g-C₃N₄ quantum dots of photosensitizer and UCNPs coated with mesoporous silica to obtain multifunctional nanoparticles.Under the irradiation of near-infrared light at 808 nm,the CuS component can absorb light energy and convert it into heat for photothermal treatment.Since g-C₃N₄ quantum dots can generate hydroxyl radicals and superoxide anions,the blue-violet light emitted by UCNPs under 808 nm light excitation can stimulate g-C₃N₄ quantum dots to achieve photodynamic therapy due to the doping of Tm³⁺and Nd³⁺.This process can make full use of the energy of excitation light and emitted light.Compared with traditional g-C₃N₄ nanosheets,the size of g-C₃N₄ quantum dots is very small.Therefore,the integrated nanocomposite is more likely to be engulfed by cells and used for cancer treatment.Then,the surface of the nanocomposite was further modified with polyethylene glycol(PEG)and folic acid(FA),so that the final sample had excellent biocompatibility and cancer cell targeting.Due to the doping of rare earth ions,the material posses the capability of up-conversion fluorescence imaging,computed tomography and magnetic resonance imaging.In addition,through cell viability,reactive oxygen species detection,photothermal conversion efficiency,and in vivo anti-cancer experiments,the materials have been shown to have cancer cells targeted photothermal,photodynamic synergistic therapeutic effects.The liquid phase stripping method was used to sonicate bulk black phosphorus(BP)into black phosphorus nanosheets.The positively charged CuS-loaded upconversion nanoparticles were loaded on the negatively charged black phosphorus sheets by electrostatic adsorption achieving the first successful integration of CuS and black phosphorus nanosheets.Then the material is loaded with the chemical drug doxorubicin(DOX).Due to the large specific surface area of black phosphorus and the pores of mesoporous silica,the drug loading rate was as high as 77.4%,which led to a significant increase in anti-cancer effects.Drug release can also be monitored by changing the red/green ratio in the spectrum.In vitro and in vivo experiments show that the material can be used for photothermal,photodynamic,and chemical synergistic treatment under the irradiation of 808 nm near-infrared light,and can be used for computer tomography and magnetic resonance imaging.