Therapeutic exosomes in cancer: efficacy and safety perspectives

Extracellular vesicles (EVs) are essential signalling mediators within biological systems, playing a vital role in cell-to-cell communication. In cancer research, exosomes (a subpopulation of EVs that originate from endosomes) have become the most highlighted area of study in the current decade. Tumor-derived exosomes (TEXs) participate in tumor development and cancer progression. They regulate tumor cell growth, immune suppression, angiogenesis, metastasis, epithelial-mesenchymal transition and organ-specific metastasis. The molecular signatures of exosomes, including DNA, RNA, proteins, and lipids, play a crucial role in cancer development and hold significantly promising biomarkers for cancer. Beyond their pathological role, EVs offer a cell-free platform for the development of therapeutic methods for cancer. This phenomenon is having a huge impact compared to cell-based therapy by overcoming several limitations, such as toxicity, high cost, and effectiveness. Multiple therapeutic exosome sources are available, including stem cell-derived exosomes, plant-derived exosomes, immune cell-derived exosomes, and modified exosomes. Compared with conventional cell-based therapies, exosome-based strategies present several advantages, including reduced toxicity, biocompatibility, improved stability, and specificity. Multiple therapeutic exosomes sources are available, including stem cell-derived exosomes, plant cell-derived exosomes, immune cell-derived exosomes, milk-derived exosomes, bacteria-derived exosomes, and modified/engineered exosomes. The therapeutic impact of these exosomes is strongly influenced by multiple factors, such as their cellular origin, heterogeneity, inner cargos, surface charge, surface composition and physicochemical properties. This review discusses the current limitations, key challenges and future perspectives related to exosome-based therapeutics with particular emphasis on the comparative and translational potential of different exosome sources.