Specific enrichment of urinary exosomes and exosomal glycopeptides by coefficient affinity of integrated l-cysteine and titania

Exosome and inclusive cargoes have manifested significant function in different biological events. In particular, glycopeptides in exosome are closely associated with occurrence and development of various diseases. Developing advanced tools is highly desired to enrich glycopeptides from exosomes, and enrich exosomes from complex biological samples as well. In this work, integration of l-cysteine and titania onto the surface of magnetic nanoparticles is designed to realize the coefficient affinity towards exosomes and inclusive glycopeptides. Benefiting from the synergistic affinity, we separate exosomes from human urine concentrate directly, which was proved by the detection of three typical antigen markers of exosomes. Furthermore, hardly any exosomes remained on materials after ultrasonication, which confirmed the good capture performance of Fe3O4@TiO2@l-Cys and high release effect of direct lysis. Moreover, 146 glycopeptides corresponding to 77 glycoproteins were successfully identified from captured exosomes. These satisfactory results will inspire more efforts to be devoted to this field and will be extremely helpful to in-depth information excavation of biological markers, especially disease-related ones, through exosomes and inclusive glycopeptides.