Study On The Application Of Copper Selenide Nanoparticles In Tumor Markers Detection And Cancer Cell Killing

Cancer,namely the malignant tumor,is a disease that seriously endangers human life and health,has a high incidence and mortality rate,and is one of the major global public health problems.Early diagnosis and effective treatment of cancer are of great significance to improve the survival rate of patients.Among them,tumor markers are a class of active substances that reflect the occurrence and development of tumors and indicate the presence and growth of tumors.In general,the levels of tumor markers in cancer patients are generally higher than those in normal people,and early diagnosis of cancer can be achieved by detecting their concentrations.The traditional methods of cancer treatment often have problems such as incomplete resection of tumor tissue and large side effects.Therefore,it is necessary to explore efficient and less toxic treatment modes in order to ensure the good therapeutic and to reduce the toxic side effects on normal tissues.Facing the increasing number of cancer patients and deaths in the world,it is an inevitable trend in the development of nanomedicine to develop and design new nanoprobes for early diagnosis and treatment of cancer.Copper selenide nanoparticle is a kind of p-type semiconductor nanomaterial with various crystal structures and stoichiometric components.For their special copper vacancies and high carrier density,nonstoichiometric copper selenide nanoparticles(Cu_2-xSe)have strong local surface plasmonic resonance（LSPR）absorption in the near-infrared region,and they can be used as a near-infrared optical probe and photothermal agent for cancer diagnosis and treatment.Also,due to their tunable copper defect structure,copper selenide nanomaterials also have a good catalytic activity,but their biological applications are not fully discussed.Based on this,this paper focuses on the application of copper selenide nanomaterials in the early diagnosis and treatment of cancer,the following three areas have been explored:（1）FRET-based Cu_2-xSe@HA-Rh6G fluorescent nanoprobe for hyaluronidase detection and imaging.We selected rhodamine 6G（Rh6G）and hyaluronic acid（HA）coated copper selenide nanoparticles(Cu_2-xSe@HA)as the donor and receptor pairs of fluorescence resonance energy transfer（FRET）to construct a"Turn On"fluorescent sensing platform for the detection of the novel tumor marker hyaluronidase（HAase）and targeted cancer cell imaging.The Cu_2-xSe@HA had a wide absorption band in the ultraviolet to near-infrared region;can interact with Rh6G as a FRET receptor,inducing the fluorescence quenching of Rh6G.In the presence of HAase,HA was catalytically degraded,thus,the FRET process between Cu_2-xSe@HA and Rh6G was interrupted and the fluorescence intensity of the probe(Cu_2-xSe@HA-Rh6G)was restored.The change of relative fluorescence intensity was linearly related to HAase concentration in the range of 0.1-10.0 U/m L,and the detection limit was 0.06 U/m L.The platform was successfully used for sensitive detection of HAase in human urine,and compared with ELISA,the relative error of the experimental results was-4.1%-7.1%.The probe achieved targeted cancer cells imaging by taking advantage of the property that HA can specifically target the overexpressed CD44 receptor in cancer cells.（2）The Cu_2-xSe@M（M=PAH,PSS,SDS）sensor arrays for the detection of multiple proteins.Three kinds of Cu_2-xSe@M（M=PAH,PSS,SDS）with different copper defects were synthesized in this experiment,which had different peroxidase-like activities.They had the good nanoenzyme activyties that can catalyze the oxidation of 3,3’,5,5’-tetramethylbenzidine dihydrochloride（TMB）with hydrogen peroxide（H₂O₂）to produce blue oxidized TMB（Ox TMB）.Proteins with different molecular weights and isoelectric points can interact with Cu_2-xSe@M,producing different absorbance signals.Cu_2-xSe@M was used as the sensor receptor to construct the sensor array,and the absorbance change of Ox TMB was used as the signal response,and the data were processed by linear discriminant analysis（LDA）,which could successfully identifiy alpha fetoprotein（AFP）,prostate specific antigen（PSA）,human serum albumin（HSA）,hemoglobin（Hb）,trypsin（Try）and pepsin（Pep）at different concentrations.The AFP and PSA in the range of 0.1-5.0μmol/L could be quantitatively analyzed,and R² were 0.987and 0.997,respectively.The sensor was used in the identification and prediction of cancer patients（liver cancer and prostate cancer）and healthy people with an accuracy of 100%.（3）Cu_2-xSe@HA-DOX for synergistic chem-chemodynamic killing of cancer cells.The drug doxorubicin（DOX）was loaded on the synthesized Cu_2-xSe@HA in work（1）to form Cu_2-xSe@HA-DOX composite nanomaterials.On the one hand,Cu_2-xSe@HA-DOX can interact with HAase overexpressed in cancer cells to release DOX for chemotherapy;On the other hand,Cu_2-xSe@HA can generate large amounts of hydroxyl radicals by Fenton-like reactions in the tumor microenvironment（TME）for chemodynamic therapy to cooperate to kill cancer cells.The results of cell imaging experiments showed that red fluorescence of free DOX was observed in human laryngeal cancer epithelial cells（HEp-2）co-incubated with Cu_2-xSe@HA-DOX,and further treatment with DCFH-DA resulted in the appearance of green fluorescence observed in the cells,indicating the generation of a large amount of reactive oxygen species.Cytotoxicity experiments showed that in contrast to the single treatment mode,Cu_2-xSe@HA-DOX showed better chemo-chemodynamic synergistic killing effect.In conclusion,copper selenide nanoparticles were applied to realize the detection of tumor markers hyaluronidase and multiple proteins,and further to be used in the synergistic killing of cancer cells the cooperative treatment of cancer cells based on their unique optical properties and good catalytic activity.Our wirk broadened the application of copper selenide nanomaterials in the diagnosis and treatment of cancer.