Extracellular vesicles (EVs) are membranous vesicles secreted by both prokaryotic and eukaryotic cells and play a vital role in intercellular communication. EVs are classified into several subtypes based on their origin, physical characteristics, and biomolecular makeup. Exosomes, a subtype of EVs, are released by the fusion of multivesicular bodies (MVB) with the plasma membrane of the cell. Several methods have been described in literature to isolate exosomes from biofluids including blood, urine, milk, and cell culture media among others. While differential ultracentrifugation (dUC), has been widely used to isolate exosomes, other techniques including ultrafiltration, precipitating agents such as poly-ethylene glycol (PEG), immunoaffinity capture, microfluidics and size exclusion chromatography (SEC) have emerged as credible alternatives with pros and cons associated with each. In this review, we provide a summary of commonly used exosomal isolation techniques with a focus on SEC as an ideal methodology. We evaluate the efficacy of SEC to isolate exosomes from an array of biological fluids, with a particular focus on its application to adipose tissue-derived exosomes. We argue that exosomes isolated via SEC are relatively pure and functional, and that this methodology is reproducible, scalable, inexpensive, and does not require specialized equipment or user expertise.

Asthma is the most common chronic disease in children. It is characterized by difficulty in breathing and chronic airway inflammation associated with narrowing of the airways, and airway hyperresponsiveness. If left untreated, asthma can lead to respiratory distress and even death. A number of medications are available and prescribed to manage asthma. Yet despite that, only half of the asthmatic patients are able to control their condition. Extracellular vesicles (EVs) play an important role in transporting contents such as nucleic acids, proteins, and lipids to other cells. While EVs have been extensively studied as biomarkers of various pathological states, evidence indicates that they can play protective and therapeutic roles in mitigating diseases such as cancer, cardiovascular disease and asthma. Here we propose to conduct a systematic review that provides a detailed analysis of the therapeutic effect of EVs in mitigating the primary (inflammation, airway hyperresponsiveness) and secondary outcomes (airway remodelling, molecular indices of cellular signalling, and inflammatory mediators in serum) associated with asthma in preclinical studies.