Vesicles, like living cells, are membrane-enclosed “sacs” of fluid that can cushion molecular cargo such as pharmaceutical drugs. If a drug is successfully encapsulated into a vesicle carrier and the carrier remains intact, it can be delivered directly for therapeutic treatment. Inside the host, vesicles protect the drug cargo and can efficiently target recipient cells to deliver the drugs safely. This type of “targeted” delivery provides advantages over more extreme methods of treatment such as chemotherapy, which can damage healthy cells in the host.