Construction Of Near-infrared Fluorescent Nanoprobes And Their In Vitro And In Vivo Detection Of Breast Cancer Biomarkers

In recent years,the morbidity and the mortality of breast cancer have been increasing,and it seriously threatens women's life and health.In 1992,the breast cancer prevention campaign marked by the wearing of the "Pink Ribbon" was launched around the world.The purpose of the campaign was "early prevention,early detection,and early treatment".In general,the appearance of tumor markers in the human body is usually earlier than the clinical manifestations of cancer.Therefore,the high sensitive and high specific recognition and detection of the tumor markers have great clinical significance in the early diagnosis,condition monitoring and prognosis of breast cancer.Developing highly sensitive methods for the detection of breast cancer markers has become a research focus.Because of fluorescence analysis has high sensitivity and selectivity,and the fluorescent nanomaterials own unique optical properties,the fluorescence strategies based on near-infrared fluorescent nanomaterials have been widely used for the identification and detection of tumor markers.In this thesis,combining high sensitivity of fluorescence technology,such as fluorescence resonance energy transfer and in situ fluorescence imaging,and the unique properties of near-infrared fluorescent nanomaterials,a series of fluorescence strategies for the detection of tumor markers were developed.This thesis is divided into the following two parts:(1)The concentration of human epidermal growth factor receptor 2(HER2)in blood of breast cancer patients is significantly higher than that of normal people.Compared with other types of breast cancer,HER2 positive breast cancer is more malignant,more resistant,and more likely to relapse and metastases.Therefore,early detection of HER2 in breast cancer patients and identify the type of breast cancer can achieve the best therapeutic effect.In this work,an enhanced near-infrared(NIR)FRET biosensing system based on the novel donoracceptor pair(MnCuInS/ZnS@BSA and urchin-like Au NPs)was developed for the sensitive detection of HER2 protein.In this strategy,MnCuInS/ZnS quantum dots(QDs)were chosen due to their near-infrared(NIR)emission,high quantum efficiency and low toxicity.Amounts of MnCuInS/ZnS QDs were encapsulated in BSA to form MnCuInS/ZnS@BSA nanoparticles,which could easily transfer MnCuInS/ZnS QDs from organic phase into aqueous solution,and the formed nanoparticles were applied as the energy donor which significantly enhanced the fluorescence intensity.A novel urchin like AuNPs with superior quenching ability for near infrared light was designed as an energy receptor.By combining the optical advantages of NIR QDs encapsulated BSA nanoparticles with the excellent fluorescence quenching ability of urchin like Au NPs,the proposed FRET-based biosensor realized enhanced FRET effect for highly sensitive detection of HER2 in human serum samples.A wide detection range(2 to 100 ng mL-1)and a low detection limit(1 ng mL-1)were obtained.The biosensor has an important application prospect in vivo diagnosis of breast cancer.(2)The high effective screening of heterogeneous tumor subtypes is useful for the diagnosis and symptomatic treatment of breast cancer.We developed a near-infrared(NIR)QDs-based fluorescence nanoprobe for accurate,rapid and highly specific labelling of HER2 overexpressed breast cancer.HER2 antibodies attached to the surface of MnCuInS/ZnS@BSA to obtain the fluorescence nanoprobe.We proved that MnCuInS/ZnS@BSA nanoparticles exhibit low cytotoxicity via MTT assay.This study indicates that MnCuInS/ZnS@BSA nanoparticles can be used as effective near-infrared fluorescent nanoprobes for selective screening of HER2 overexpressed cancer cells,and providing a platform for the investigation of advanced pathways to distinguish the different breast cancer subtypes.