Fig. 4

sEVs in cancer diagnosis and therapy. sEVs can be extracted from various bodily fluids. Analysis of the molecular contents, including proteins and nucleic acids, could provide abundant information about the molecular profile of cancer and be used for early diagnosis, prediction of progression and metastasis, typical classification, and detection of clinical responses. sEVs derived from various cells can be used as effective delivery vesicles for several cancer therapies. For chemotherapy, sEVs can be loaded with enzymes or their encoding genes that convert prodrugs into cytotoxic agents for systemic administration. Naïve tropism, surface modification and magnetic nanoparticles can achieve the target delivery of chemotherapeutics. For gene therapy, gene editing agents can be loaded into sEVs and achieve target editing by naïve tropism, surface modification or directly anchored on the surface of sEVs. For photothermal (PTT) or photodynamic (PDT) therapy, photosensitizers can be coloaded with magnetic nanoparticles or auxiliary effector molecules and delivered by sEVs modified by surface peptides targeting the membrane or nucleus to enhance their therapeutic effects. For immunotherapy, antibodies targeting T and cancer cells can both be loaded on the surface to enhance T cell cytotoxicity. Target blockage of CD47 can inhibit the immune escape of cancer cells. sEVs derived from CAR-T cells have similar cytotoxicity to tumor cells, minimal adverse side effects and suffered immunosuppression compared with CAR-T cells. They can also carry antigens or drugs to enhance the therapeutic effects. Additionally, cytokines can also be loaded and delivered by sEVs