Exosomes as immunotheranostic nanoparticles

Abstract

Background: Exosomes are small biological membrane vesicles that measure 30 to 100 nm in diameter. They are involved in a wide array of biological activities, such as cell-cell communication, signal transduction, transport of genetic materials, and modulation of immune response. Evidence indicates that they can be used as not only therapeutic agents targeted against disease but also diagnostic biomarkers for pathologic conditions.

Objective: In this review, we endeavor to present exosomes as immunologic agents that can be used as pioneering cancer vaccines to prime the immune system and explicate their therapeutic and diagnostic capabilities.

Methods: An extensive literature search for studies that involved the use of exosomes as immunotheranostic nanoparticles was conducted using PubMed, ISI Web of Knowledge, and Google Scholar. Clinical trials that involved exosomes were also compiled by searching the clinicaltrials.gov database.

Results: In its therapeutic facet of application, exosomes can be used as vehicles for drug or gene delivery. These biological vesicles have been found to have excellent host biodistribution and biocompatibility, issues often presented with gene delivery vehicles. Diagnostically, exosomes may prove to be useful biomarkers that are able to surpass current setbacks of modern diagnostic testing, which include invasive methods. Finally, current evidence has implied that the use of exosomes could form the basis for the development of future cell-free cancer vaccines.

Conclusion: Exosomes have numerous functions, and their double-edged features make the scope of their clinical applications, as both a diagnostic and therapeutic tool, immense.

Keywords: Exosomes; cancer vaccine; immunotherapy; nanomedicine; nanoparticles; theranostics.