Application Of Zinc Ion In The Bioimaging Of Cancerous Cell And The Xenograft Tumor Mouse Model In Situ

Cancer is one of the major diseases with high mortality and has a serious threat to the health life of human. The biomedical field has regarded the early accurate diagnosis and effective treatment of cancer as the research focus. In recent years, with the development of nanotechnology more and more nanomaterials are used in the diagnosis and treatment of cancer. The use of nanomaterials to tumor fluorescence bio-imaging plays a vital role in the early diagnosis and real-time monitoring of cancer. However, compared to nano-materials, such as fluorescent nanoclusters, nanoparticle and fluorescent quantum dots, etc., the use of chemical molecules in situ biosynthesized of fluorescent nanoclusters to fluorescence bio-imaging in cell is more simple and convenient and has a better biocompatibility.Zinc plays an important role in the structure and physiological and biochemical functions in the human beings. This paper used the zinc gluconate as a source of zinc ions and studied the fluorescence bio-imaging condition of zinc ions with a variety of tumor cells (such as hepatoma cell, HepG2; human cervical carcinoma cell, HeLa; glioma cell, U87).The main research content of this paper are as follows:1) The preparation of in situ biosynthesized zinc nanoclustersThe in situ biosynthesized zinc nanoclusters were harvested from the cancer cell lines like HeLa cells incubated with DMEM contained a certain concentration of Zn(C6H 1107)2 for 24 h or 48 h at 37 ? with 5% CO2 by repetitive freeze-thaw method. The zinc nanoclusters dissolved in deionized water for the implication in the next research.2) The characterization of zinc nanoclustersThe transmission electron microscope (TEM), energy dispersion X-ray spectroscopy (EDS) and fluorescence and UV-Vis absorption spectra were used to characterized the obtained zinc nanoclusters. The results show that they have high monodispersity and no other metallic chemical element present in the biosynthesized zinc nanoclusters.3) The cytotoxicity evaluation of zinc gluconateMaterials used in clinical cancer research must have good biocompatibility and does not produce significant side effects on cells in order to avoid the interference to cells. In vitro cytotoxicity was measured by performing methyl thiazolyl tetrazolium (MTT) assays on the cells. The results showed that zinc gluconate has good biocompatibility and provided the conditions for the following research.4) The application of zinc ions in bio-imaging study of the cells and tumorsAccording to the results of the cytotoxicity study, a variety of tumor cells (hepatoma cell, HepG2 cells; human cervical carcinoma cell, HeLa cells; glioma cell, U87 cells) were cultured with an appropriate concentration of zinc gluconate. Laser confocal fluorescence microscope were used to perform confocal fluorescence microscopy imaging of these cells. The results showed that compared with normal cells, zinc ion has a good bio-marking effect to cancer cells. Subcutaneous injection of zinc gluconate around xenograft tumors allowed the clear observation of bright fluorescence around the tumor after 24 hours.In this study, we in situ biosynthesized excellent fluorescent zinc nanoclusters based on the specific internal environment of tumor cells/tissues. This strategy implements in vivo self-bio-imaging of tumors and provides a safe and simple new method of biological imaging for cancer diagnosis and treatment.