Preparation Of Functional Nanoparticles And Construction Of Corresponding Analytical Methods For Breast Cancer Cells Detection

Breast cancer is becoming a major threat to women's health.Its related diagnosis and treatment have always been a hot and difficult issue in biomedical research.As a highly heterogeneous tumor,there is a genotypic to phenotypic difference between different individuals and even among different tumor cells within the same patient.Therefore,how to distinguish the breast cancer cells from normal cells in patients during the diagnosis and to carry out gene sequencing or other related biochemical analysis will be of great significance to the pathogenesis,prediction and later diagnosis and treatment of the cancer.The above demand has inspired people to explore the relevant detection methods for breast cancer cells.Usually,there are some specific changes in the abnormal process of cell differentiation or proliferation,such as the antigen and bioactive substances produced by the tumor tissue or cells due to the abnormal expression of oncogene,antitumor gene,or other tumor-related genes and their products(such as MUC1 tumor protein,intracellular telomerase,etc.),which are known as tumor markers and play an important role in tumor monitoring.On the other hand,the rapid development of nanotechnology provides an opportunity for the construction of highly sensitive detection methods,and greatly promotes the progress of analytical methods.These nanomaterials can be combined with specific molecules(such as imaging reporter molecules,antigens,antibodies and aptamers,etc)to achieve the specific targeting of tumor biomarkers to improve the sensitivity and specificity of cancer cell detection.Based on the above background,this paper aims at the detection of breast cancer.Several functional nanoparticles are prepared and modified,and the corresponding detection methods are constructed to analyze and detect breast cancer cells by their characteristics.The specific contents are as follows: 1.Carbon nanospheres(CNSs)-based fluorescence aptasensor for targeted detection of breast cancer cell MCF-7In this chapter,we mainly discussed the targeted detection of MCF-7 breast cancer cells by constructing a fluorescent aptasensor based on the CNSs as the sensing platform and combination with MUC1 aptamer to distinguish them from MCF-10 A normal mammary cells.The experimental results show that:(1)As a new fluorescence quenching material,CNSs obtained from glucose carbonization not only have a high fluorescence quenching efficiency(98.8%),but also have a weaker cytotoxicity and good dispersity.(2)The constructed CNSs/P0-FAM aptasensor can specifically identify and combine the overexpressed MUC1 protein on the surface of the MCF-7 cells to selectively distinguish between MCF-7 cells and MCF-10 A cells;(3)The MUC1 peptide was used as a mimic of the tumor antigen MUC1.For extracellular detection of the MUC1 peptide,the fluorescence intensity was almost linearly enhanced and the detection limit was 25 nM when the peptide concentration was in the range of 0-6 ?M.2.Sensitive detection and in situ imaging of telomerase activity in cells based on PG/CNSs(patchy gold-on CNSs)mimic-HCR probeThis chapter mainly discussed the preparation of PG/CNSs nanocomposite by adsorption-reduction method using CNSs as the substrate.Then,the PG/CNSs mimic-HCR probe was constructed by introducing biomolecules in the modification and combining with hybridization chain reaction(HCR).And the intracellular telomerase activity was highly sensitively detected and in situ imaging by utilizing PG/CNSs mimic-HCR probe.In addition,PG/CNSs are well-absorbed in the near-infrared region and have good photothermal conversion capability.As a good photothermal agent,photothermal treatment of MCF-7 cells was performed.The experimental results show that:(1)Although PG/CNSs probe can be used to monitor telomerase activity in various cancer cells,PG/CNSs mimic-HCR probe has a more sensitive fluorescence imaging ability and can detect telomerase activity in living cells more sensitively,especially for cells with low telomerase activity such as MCF-7.(2)Sensitive detection of intracellular telomerase activity by PG/CNSs mimic-HCR probe can distinguish normal cells from cancer cells;(3)PG/CNSs mimic-HCR probe can be used to ablate MCF-7 cancer cells through photothermal therapy,therefore photothermal therapy of the PG/CNSs mimic-HCR probe in cancer cells is effective.3.Preliminary study on the detection of MCF-7 cells based on SERS effectThis chapter mainly discussed Au nanostars synthesized by seed growth method were used as the substrate to constructed targeted SERS probe to detect and distinguish between MCF-7 cells and MCF-10 A cells by introducing MUC1 aptamer and Raman reporter molecule,4-mercaptobenzoic acid(4-MBA).The preliminary experimental results show that:(1)The synthesized Au nanstars can produce strong SERS enhancement signal to 4-MBA;(2)The targeted SERS probe based on Au nanstars can specifically target and be bound on the surface of MCF-7 cells,and the SERS enhancement signal can be detected on the surface of the MCF-7 cells,thereby achieving a preliminary distinction between MCF-7 cells and MCF-10 A cells.