Fig. 3

Schematic illustration of pre-isolation modification methods. A Exosomes from target ligand (avidin) labeled and anti-tumor drugs encapsulated donor cells for further labeling with avidin complex [90]. Reproduced with permission, Copyright 2021, Elsevier. B Fusion protein modulation in parent cells for enriching ribonucleoproteins (RNPs) in exosomes [91]. Reproduced with permission, Copyright 2021, Wiley. C Preparation of exosomal membrane-coated DOX@PSiNPs by exocytosis following DOX@PSiNPs incubation in parent cells [92]. Reproduced with permission, Copyright 2019, Springer Nature. D Dye-labeled exosomes from dye-labeled metabolic glycoengineered donor cells via biorthogonal click chemistry [93]. Copyright 2020, American Chemical Society