Extracellular Vesicles as Drug Delivery Systems in Organ Transplantation: The Next Frontier

Harry V M Spiers; Lukas K J Stadler; Hugo Smith; Vasilis Kosmoliaptsis

doi:10.3390/pharmaceutics15030891

Extracellular Vesicles as Drug Delivery Systems in Organ Transplantation: The Next Frontier

Pharmaceutics. 2023 Mar 9;15(3):891. doi: 10.3390/pharmaceutics15030891.

Authors

Harry V M Spiers^{1

2}, Lukas K J Stadler^{1

2}, Hugo Smith¹, Vasilis Kosmoliaptsis^{1

2}

Affiliations

¹ Department of Surgery, University of Cambridge, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK.
² NIHR Blood and Transplant Research Unit in Organ Donation and Transplantation, University of Cambridge, Cambridge CB2 0QQ, UK.

Abstract

Extracellular vesicles are lipid bilayer-delimited nanoparticles excreted into the extracellular space by all cells. They carry a cargo rich in proteins, lipids and DNA, as well as a full complement of RNA species, which they deliver to recipient cells to induce downstream signalling, and they play a key role in many physiological and pathological processes. There is evidence that native and hybrid EVs may be used as effective drug delivery systems, with their intrinsic ability to protect and deliver a functional cargo by utilising endogenous cellular mechanisms making them attractive as therapeutics. Organ transplantation is the gold standard for treatment for suitable patients with end-stage organ failure. However, significant challenges still remain in organ transplantation; prevention of graft rejection requires heavy immunosuppression and the lack of donor organs results in a failure to meet demand, as manifested by growing waiting lists. Pre-clinical studies have demonstrated the ability of EVs to prevent rejection in transplantation and mitigate ischemia reperfusion injury in several disease models. The findings of this work have made clinical translation of EVs possible, with several clinical trials actively recruiting patients. However, there is much to be uncovered, and it is essential to understand the mechanisms behind the therapeutic benefits of EVs. Machine perfusion of isolated organs provides an unparalleled platform for the investigation of EV biology and the testing of the pharmacokinetic and pharmacodynamic properties of EVs. This review classifies EVs and their biogenesis routes, and discusses the isolation and characterisation methods adopted by the international EV research community, before delving into what is known about EVs as drug delivery systems and why organ transplantation represents an ideal platform for their development as drug delivery systems.

Keywords: allograft rejection; drug delivery systems; exosomes; extracellular vesicles; ischemia reperfusion injury; machine perfusion; organ transplantation.

Publication types

Review

Grants and funding

The research presented in this manuscript received funding from the National Institute for Health Research Blood and Transplant Research Unit (NIHR BTRU) in Organ Donation and Transplantation at the University of Cambridge in collaboration with Newcastle University and in partnership with NHS Blood and Transplant (NHSBT). We gratefully acknowledge funding from an NIHR Fellowship (PDF-2016-09-065, V.K.) and NIHR Academic Clinical Fellowship (ACF-2020-14-001, H.V.M.S.). V.K. acknowledges funding as a PI Terasaki Scholar. The views expressed are those of the authors and not necessarily those of the National Health Service, the National Institute for Health Research, the Department of Health or National Health Service Blood and Transplant.