TABLE 4.
Methods for prolonging EV circulation time.
| Modifying moieties | Engineering modification methods | EV origin | Main achievements | Ref |
|---|---|---|---|---|
| PEO | Chol-DNA | Mesenchymal stem cells | Higher stability and blood circulation time without altering tissue distribution profiles | Lathwal et al. (2021) |
| Dextran sulfate | Parental cell co-incubation | HEK293 and all mouse cell lines | Decreased EV liver clearance in mice and a significant increase in EV production | Watson et al. (2016) |
| cCHP nano gel | Polyvalent electrostatic interactions/Chol | Mouse macrophage cells | Efficient delivery in a functionally intact state | Sawada et al. (2020) |
| PEG | PEG-lipids | Neuro 2A | Allowed the application of a range of targeted ligands/antibodies | Kooijmans et al. (2016b) |
| Improved cell specificity and prolonged circulation time | ||||
| ABD | Lamp2B | HEK-293T and AEC cells | Extended cycle time of EV and enrichment of EVs in lymph nodes | Liang et al. (2022) |
| PHA | MGE/click chemistry | MDA-MB-231 and HCT-116 | The PHA-EVs exhibited high targeting efficiency with prolonged circulation in the bloodstream of animal models with tumor and RA | Lim et al. (2021) |
Abbreviations: PEO, polyethylene oxide; PEG, polyethylene glycol; ABD, albumin binding domains; Chol, cholesteryl; PHA, PEGylated hyaluronic acid; MGE, metabolic glycoengineering; MDA-MB-231, a human breast cancer cell line; HCT-116, a human colon carcinoma cell line; HEK, human embryonic kidney cell; AEC, alveolar epithelial cell; RA, rheumatoid arthritis.