Chemically Construct Cell-macromolecule Conjugates And Achieve In Situ Quantitative Detection

In the treatment of malignant tumors,immunotherapy is one of the hopes to curing cancer.The key point of tumor immunotherapy is to enhance the recognition of tumor cells by the immune system.For example,CAR-T and PD-1 / PD-L1 solve the problem of T cell recognition of tumor cells.However,immunotherapy techniques have great limitations in solid tumors.We designed a "and" gate fluorescent probe LS to achieve controllable modification and quantitative tracing of tumor cells.The fluorescent probe LS has DBCO and norbornene,these groups can be clicked chemistry.Fluorescent probes provide a visual means for tumor cells to introduce new targets that can be recognized by the immune system.Therefore,we designed a fluorescent probe LS with dibenzocyclooctyne and norborneene,and studied its optical properties.The main contents are as follows:1.In the first part,fluorescent probe LS,tetrazine and tetrazine-PEG were synthesized.2.In the second part,fluorescence probe LS reacted with azide and tetrazine small molecules,azide and tetrazine macromolecules.When the fluorescent probe LS reacts with the azide or tetrazine molecule,the fluorescence does not increase;when the fluorescent probe LS reacts with the azide and tetrazine molecule simultaneously,the fluorescence is enhanced.Only when both DBCO and norbornene on the fluorescent probe LS react with molecules,the fluorescence of the fluorescent probe LS will be enhanced.3.In the third part,fluorescent probes are used on the surface of tumor cells.Tumor cells are cultured with unnatural sugar with an azide group,so that the surface of the tumor cell has an azide group.Fluorescent probe LS and tetrazine PEG were added to the cell culture medium.Finally,it was observed that there was a layer of red fluorescent on the surface of tumor cells.Experiments show that the fluorescent probe LS can label tumor cells.