Fig. 6

Precondition and engineering strategies of EV-based fibrosis therapy. (A) Viral vectors or plasmids are often used as endogenous loading approach to express genes of interest in living cells, which can promote expression of proteins, nucleotides, or other molecules. These components in cells can then be packed into EVs(a). Exogenous cargos such as can be directly transported into EVs by electroporation, incubation, ultrasound, or extrusion(b). (B) The membrane of EVs can be modified by metabolic labeling, click chemistry, hydrophobic insertion, and ligand binding(a). Liposome mediate membrane fusion endows EVs with specific contents and ligands(b). (C) Iron oxide nanoparticles incubated with living cells can be taken and encapsulated into EVs, which are able to be guided by magnetism(a). Combination with hydrogel enables EVs local delivery(b). (D) Pretreat cells by hypoxia, cytokines, and some other chemical and physical elements change the physiological characteristic of EVs secreted by them