Engineered extracellular vesicles: potentials in cancer combination therapy

Extracellular vesicles (EVs) are a group of secretory vesicles with cell-derived membrane and contents. Due to the cargo delivery capability, EVs can be designed as drug delivery platforms for cancer therapy. Biocompatibility and immune compatibility endow EVs with unique advantages compared with other nanocarriers. With the development of this field, multiple ingenious modification methods have been developed to obtain engineered EVs with desired performance. Application of engineered EVs in cancer therapy has gradually shifted from monotherapy to combinational therapy to fight against heterogeneous cancer cells and complex tumor microenvironment. In addition, the strong plasticity and load capacity of engineered EV make it potential to achieve various combinations of cancer treatment methods. In this review, we summarize the existing schemes of cancer combination therapy realized by engineered EVs, highlight the mechanisms and representative examples of these schemes and provide guidance for the future application of engineered EVs to design more effective cancer combination treatment plans. Graphical Abstract