Design Of Fluorescent Probes Based On Supramolecular Recognition For Detection Of Endoplasmic Reticulum And Tumor Cells

Based on the core structure of green fluorescent protein,phydroxybenzylideneimidazolidinone(HBDI),as the parent fluorophore and the supramolecule cucurbituril CB7,we have designed and synthesized two fluorescent probes.A novel fluorescent probe for endoplasmic reticulum localization was designed and synthesized by utilizing the characteristics of proper amphiphilicity to facilitate the absorption of endoplasmic reticulum in cells.In addition,a fluorescent probe based on CB7 was designed and synthesized on the strength of the principle of supramolecular host-guest recognition and high affinity binding of folic acid receptor and folic acid on the surface of tumor cells to detect tumor cells with high expression of folic acid receptor.(1)A novel amphiphilic fluorescent probe was designed and synthesized for targeting the endoplasmic reticulum for the first time,of which HBDI served as the fluorophore precursor.One end of the fluorophore is connected to the long chain of octadecane as the hydrophobic part,which can be combined with the hydrophobic chain in the phospholipid bilayer by hydrophobic force.Only in this way can it be inserted into the cytomembrane and then this structure will have the function of biofilm localization.At the same time,the hydrophilicity and twist structure of the HBDI fluorophore precursor give this probe a good amphiphilic property.Thus,the probe has good biocompatibility.And appropriate amphiphilicity can promote the absorption of the endoplasmic reticulum(ER),so that it can be localized to the endoplasmic reticulum.Furthermore,before connected to the endoplasmic reticulum,the fluorescence signal of this probe was weaker due to the rotating vibration of the structure of BDI.Once the probe was located on ER by hydrophobic action,its torsion was inhibited and the fluorescence was recovered.Therefore,this probe has fatal potential value for the study of life activity processes involving endoplasmic reticulum.(2)In view of specific binding of folic acid receptor and folic acid on the surface of tumor cells and the mechanism of ultrahigh affinity binding of supramolecular locking system,such as between CB7 and adamantane,a probe system FA-ADA-CB7-CF was designed for highly selective detection of tumor cells.This probe system has fluorescent response to epithelial malignant tumor cells such as MCF-7 cells(human breast cancer cells)and Hela cells(human cervical cancer cells).But it has no fluorescent response to normal cells such as CHO-K1 cells(normal mouse ovarian cells).In addition,only probe CB7-CF has no fluorescence response to MCF-7 and Hela cells,which indicates that only the system of FA-ADA-CB7-CF can be utilized to specifically recognize tumor cells.Furthermore,the probe has low toxicity,strong light stability,of which the fluorescence is not easy to quench.Therefore,the system is particularly suitable for research of live cell imaging under continuous irradiation of a laser confocal microscope.The probe system also has fluorescent response to tumor tissue sections,but not to normal tissue sections.Thus,the establishment of this probe system potentially plays a fatal role in the diagnosis and treatment of tumors along with the construction of tumor-targeted drug release systems.