Extracellular vesicles (EVs) are membrane vesicles (MVs) playing important roles in various
cellular and molecular functions in cell-to-cell signaling and transmitting molecular signals to adjacent
as well as distant cells. The preserved cell membrane characteristics in MVs derived from live cells, give
them great potential in biological applications. EVs are nanoscale particulates secreted from living cells
and play crucial roles in several important cellular functions both in physiological and pathological
states. EVs are the main elements in intercellular communication in which they serve as carriers for
various endogenous cargo molecules, such as RNAs, proteins, carbohydrates, and lipids. High tissue
tropism capacity that can be conveniently mediated by surface molecules, such as integrins and glycans,
is a unique feature of EVs that makes them interesting candidates for targeted drug delivery systems.
The cell-derived giant MVs have been exploited as vehicles for delivery of various anticancer agents
and imaging probes and for implementing combinational phototherapy for targeted cancer treatment.
Giant MVs can efficiently encapsulate therapeutic drugs and deliver them to target cells through the
membrane fusion process to synergize photodynamic/photothermal treatment under light exposure. EVs
can load diagnostic or therapeutic agents using different encapsulation or conjugation methods. Moreover,
to prolong the blood circulation and enhance the targeting of the loaded agents, a variety of modification
strategies can be exploited. This paper reviews the EVs-based drug delivery strategies in cancer
therapy. Biological, pharmacokinetics and physicochemical characteristics, isolation techniques,
engineering, and drug loading strategies of EVs are discussed. The recent preclinical and clinical
progresses in applications of EVs and oncolytic virus therapy based on EVs, the clinical challenges and
perspectives are discussed.