Frontiers in bacterial outer membrane vesicles: From basic characteristics to cancer therapy

Bacterial outer membrane vesicles (OMVs) are spherical nanostructures that originate from Gram-negative bacteria. They are gaining attention as powerful tools in cancer diagnostics and therapy due to their unique biological properties. These vesicles, which range from 50 to 250 nm in size, carry molecular components from their parent bacteria, allowing them to play important roles in bacterial defense and microbial ecosystems. Their lipid bilayer structure facilitates targeted drug delivery, while their natural immunogenic properties hold promise for cancer immunotherapy by helping overcome immune evasion in the tumor microenvironment. Moreover, OMVs have potential as biomarkers in liquid biopsies, particularly for cancers associated with bacteria, such as gastric and colorectal cancers. Their ability to interact with the intratumoral microbiota further indicates their relevance in tumor pathogenesis. This review aims to provide a comprehensive overview of the fundamental biology of OMVs and their emerging applications in cancer therapy.