| Bacterial Extracellular Vesicles (bEVs) are natural nanoscale membrane vesicles secreted by bacteria, which possess inherent advantages such as diverse sources, high stability, favorable biocompatibility and amenability to engineering, making them a promising natural bio-nano platform in the biomedical field. To achieve functional customization and clinical translation of bEVs, researchers have developed multi-dimensional engineering construction strategies. Through intrinsic genetic engineering, surface modification and drug loading encapsulation, the targeting ability, drug loading efficiency and immune regulation capacity of bEVs have been precisely optimized. In recent years, the diagnostic and therapeutic potential of engineered bEVs has been deeply explored: as novel diagnostic biomarkers, their abundance and cargo can sensitively reflect the pathophysiological state of the organism, providing a new approach for non-invasive early diagnosis of diseases; as innovative vaccine vectors, they can efficiently deliver antigens and elicit robust immune responses, becoming an important direction for the prevention and control of drug-resistant bacterial infections; as targeted therapeutic tools, they can achieve precise delivery of therapeutic molecules after engineering modification, showing synergistic therapeutic effects in tumors, tissue repair, anti-infection and other diseases. This article systematically elaborates on the basic biological characteristics of bEVs, focuses on sorting out the core construction strategies of engineered bEVs, comprehensively summarizes the latest research progress of engineered bEVs in disease diagnosis, vaccine development and targeted therapy, reviews the current research hotspots and key issues, and discusses the challenges and future development directions in the field, aiming to provide theoretical basis and practical strategies for the clinical translation of engineered bEVs and the development of novel diagnostic and therapeutic platforms. |
