Extracellular vesicles, their manufacture, and methods of treatment are described. Generally, extracellular vesicles can be generated by applying sulfhydryl blocking reagents on animal cells. Extracellular vesicles can be loaded with compounds for an intended use, such as, for example, loading an extracellular vesicle with a medicament to treat an animal. As described here, extracellular vesicles can be generated in a large scale and used for personalized treatments.