Bacterial extracellular vesicles as emerging platforms to combat multidrug-resistant bacterial infections: Mechanisms, therapeutic applications, and future prospects

Multidrug-resistant bacteria (MDRB) have become a global health crisis that challenges the effectiveness of conventional antibiotics. Bacterial extracellular vesicles (BEVs) are nanoscale bilayered membrane vesicles secreted by both Gram-positive and Gram-negative bacteria. They can encapsulate proteins, lipids, and nucleic acids, and transfer these molecules between bacteria and host cells without direct contact. Owing to their natural ability to transport bioactive molecules, BEVs have recently gained attention as potential anti-infective platforms. They can deliver antimicrobial agents directly to resistant pathogens and act as vaccine carriers by triggering innate and adaptive immunity. Advances in BEV isolation, drug loading, and bioengineering have expanded their therapeutic potential. However, challenges such as large-scale manufacturing, immunogenicity control, and regulatory standardization still hinder clinical translation. This review summarizes the mechanisms, engineering strategies, and biomedical applications of BEVs against MDRB and discusses future perspectives for their safe and effective clinical use as antimicrobial nanoplatforms.