Fig. 5
From: Emerging role of exosomes in cancer therapy: progress and challenges
Extracellular vesicle (EV) loading methods for drug delivery: (A) Exogenous Loading Method: EVs are isolated separately, and the biologic drug is produced (steps 1–4). The EVs are then loaded with the drug, which may also be a small synthetic compound. Loading can be passive or active: passive loading involves (I) drug incubation with EVs, while active methods include (II) extrusion, (III) sonication, (IV) electroporation, and (V) freeze–thaw cycles. (B) Endogenous Loading Method: This includes (I) genetic engineering and (II) incubation. Parental cells are engineered via (i) stable transduction or (ii) transient transfection. Genetic engineering removes the need for separate biologic drug production and EV loading, combining these processes for efficiency. Once the cell line is established, EV production, isolation, and drug loading are integrated. Incubation involves producing the drug and adding it to the cell culture, similar to the exogenous approach, requiring separate phases. Reproduced from ref. 41 with permission from Elsevier copyright 2024