Synthesis, Photothermal Conversion Properties And Application In Tumor Therapy Of Hollow Mesoporous Cu₇S₄ Nanomaterials

With the acceleration of the process of modern society,cancer has become the number one cause of life-threatens,so we urgently need to find an efficient treatment for cancer.Traditional treatment methods such as radiotherapy have certain shortcomings.Photothermal therapy is an emerging treatment method that uses near-infrared light to generate heat to increase the temperature around the tumor to kill cancer cells.This method has obvious results in diagnosis and treatment,with less toxic and side effects,and has been widely studied in recent years.Commonly used photothermal reagents include metal nanoparticles,carbon nanostructures,quantum dots,rare earth doped nanocrystals,porous silicon and organic nanoparticles.The semiconductor CuS NPs have attracted wide attention from researchers in nanoscience,biology,medicine and other fields due to their low cost,low toxicity,good biocompatibility,diversified diagnostic methods and great therapeutic potential.CuS has a wide near-infrared(NIR)absorption at 700-1100 nm,which is mainly derived from the d-d transition of Cu²⁺,and does not change with the change of CuS morphology and surrounding dielectric permittivity,so it can be applied to photothermal treatment.This dissertation selects Cu₇S₄ NPs with high photothermal conversion performance through theoretical simulation,and then synthesizes the Cu₇S₄NPs through experiments and applies them to photothermal therapy.The main research contents are as follows:1.Theoretical simulation of LSPR spectra of Cu₇S₄ NPs.We constructed a simple model of the Cu₇S₄ spherical shell structure,and theoretically predicted the position and intensity of its LSPR characteristic peak.The results show that the characteristic peak of LSPR is located at 900-1100 nm;further theoretical simulations of Cu₇S₄ NPs of different sizes and thicknesses show that when the size of Cu₇S₄ NPs is about 70-100 nm and the thickness is about 10 nm,it has a large absorption at about 980 nm.2.Preparation of Cu₇S₄ NPs,research on photothermal conversion performance and its in vitro test on breast cancer cells(MCF-7)and research on photothermal therapy in vivo.First,based on the results of theoretical simulations,we experimentally synthesized Cu₇S₄ NPs with the above-mentioned size and thickness and characterized them;further,the photothermal performance was investigated,and the results showed that Cu₇S₄ NPs is a kind of high photothermal Photothermal reagents with high conversion efficiency and have great application prospects in the photothermal treatment of breast cancer.Secondly,Cu₇S₄ has good biocompatibility,which increases the feasibility of its application to photothermal therapy;then,Cu₇S₄ NPs are used to load the chemotherapeutic drug DOX to form Cu₇S₄-DOX,which is used for photothermal therapy and chemotherapy of MCF-7 cells.Finally,the MCF-7 cell membrane was wrapped in Cu₇S₄-DOX to obtain Cu₇S₄-DOX@M to improve the material's targeting ability of MCF-7 cells.After Cu₇S₄-DOX@M was used for in vivo photothermal treatment of tumor-bearing mice,other physiological activities of the mice were normal.This thesis provides feasibility guidance for the construction of photothermal reagents with excellent photothermal performance,good biocompatibility and high targeting ability,in order to make it better applied to clinical and human life.