Extracellular vesicles (EVs) are membrane-enclosed structures secreted ubiquitously by cells. They are thought to mediate communication between cells. Understanding this cellular communication offers potential for new diagnostics, drug/small molecule delivery vehicles and therapeutics for a variety of medical conditions, including incurable ones such as chronic lung diseases/injury, Parkinson's disease and multiple sclerosis.

EVs have also been lauded as the new generation of medicine. In stark contrast to conventional pharmacological interventions, most of which are based on a single drug with a limited number of actions, EVs contain a multitude of naturally produced molecules that can act synergistically to activate multiple cell types and accelerate tissue repair. It is envisaged that in the future, EVs containing particular combinations of these naturally produced molecules will be able to be ‘farmed’ from cultures of specific cell types under specific conditions, and then delivered to selected tissues or organs for specific therapeutic purposes; e.g. to repair damaged lung tissue due to smoke inhalation injury or to repair myelination around nerve cells to cure multiple sclerosis.

Since the composition of EVs mirrors that of the cell from which they are secreted, EVs can be the ideal biomarkers for disease diagnosis, especially for early detection. Additionally, because of their composition, namely what is in and on EVs, they have inherent suitability to target specific cells and tissues in the body, and hence are ideal vehicles for drug delivery. The key benefit is that EVs can precisely deliver their payloads without activating the innate or acquired immune system.

While EVs present us with the possibility to revolutionise medicine – with astonishingly real possibilities for success – they are very heterogenous, have not been fully characterised, are difficult to isolate and the regulatory pathway for this new class of biologics is still not well defined.

In this book, we present state-of-the-art EV science with a specific focus on the basic biology of EV biogenesis and production, isolation, physicochemical characterisation and their role in regenerative medicine for the treatment of major medical conditions. We also present key aspects related to the standardisation and commercialisation landscape of EVs.

We hope that this book will help to advance the fundamental science of EVs and contribute to the new developments to overcome current major limitations in isolation, identification and characterisation, as well as application and commercialisation of EVs. We believe that EVs will soon become mainstream medicine.

Wojciech Chrzanowski

University of Sydney

Chwee Teck Lim

National University of Singapore

Sally Yunsun Kim

Imperial College London