Overview and Update on Extracellular Vesicles: Considerations on Exosomes and Their Application in Modern Medicine

Abstract

In recent years, there has been a rapid growth in the knowledge of cell-secreted extracellular vesicle functions. They are membrane enclosed and loaded with proteins, nucleic acids, lipids, and other biomolecules. After being released into the extracellular environment, some of these vesicles are delivered to recipient cells; consequently, the target cell may undergo physiological or pathological changes. Thus, extracellular vesicles as biological nano-carriers, have a pivotal role in facilitating long-distance intercellular communication. Understanding the mechanisms that mediate this communication process is important not only for basic science but also in medicine. Indeed, extracellular vesicles are currently seen with immense interest in nanomedicine and precision medicine for their potential use in diagnostic, prognostic, and therapeutic applications. This paper aims to summarize the latest advances in the study of the smallest subtype among extracellular vesicles, the exosomes. The article is divided into several sections, focusing on exosomes’ nature, characteristics, and commonly used strategies and methodologies for their separation, characterization, and visualization. By searching an extended portion of the relevant literature, this work aims to give a quick outline of advances in exosomes’ extensive nanomedical applications. Moreover, considerations that require further investigations before translating them to clinical applications are summarized.

Extracellular Vesicles as New Players in Drug Delivery: A Focus on Red Blood Cells-Derived EVs

“…Indeed, EVs can escape immune clearance, which makes them highly stable in blood circulation. These properties make them preferable drug delivery carriers compared to synthetic vehicles or nanoparticles [ 34 , 35 , 36 , 37 , 38 ]. Moreover, there is a clear indication that EVs can cross multiple biological barriers, as demonstrated by several studies of neuronal EVs in the cerebrospinal fluid, blood, urine, and tears [ 39 ].…”

Advances in Extracellular Vesicle Nanotechnology for Precision Theranostics

“…For example, EVs are prone to being trapped and stuck in nonspecific tissues, particularly the liver and lung, which results in insufficient targeting of EVs. [ 120 ] Several pieces of evidence suggest that the engineering of EVs can significantly improve their performance, such as targeting ability and drug loading capacity. Thus, the latest advances in engineered EVs for disease treatment will be focused on in this part.…”

Applications of Exosomes in Diagnosing Muscle Invasive Bladder Cancer

“…However, exosomes would make an excellent source for biomarkers for several reasons. Exosomes participate in cell-to-cell communication and stimulation of immune responses [ 90 , 91 ]. They can receive feedback and respond to their cellular environment.…”