Design and development of novel fluorescence sensing material for exosome recognition

Exosomes are extracellular vesicles with relatively specific expression of CD63 transmembrane protein. In this study, We designed and constructed a multisite-targeting polymer which has both fluorescence and targeting recognition. It can bond to the hydrophilic group of CD63 by connecting with hydrogen. The chemical structure and the ability to combine with CD63 of fluorescent monomer and polymer were characterized and confirmed by FTIR and 1H NMR. MTT assay was performed to detect the cytotoxicity and biocompatibility of this polymer. Then we found the cell viability was 80.64% and the hemolysis rate of erythrocyte was only 0.101% even at F concentration of 20 µM. In vitro, the proposed polymer showed better ability to enter cells after linking exosomes via CD63; in vivo, it showed the ability to bind stably to exosomes and target tumor implants.