bEVs丰富的微生物相关分子模式(MAMPs)和纳米级结构共同促进了它们的多种生物活性。基于这些固有特性，已战略性地采用涵盖物理、化学和基因改造的工程方法来增强bEVs的功能多样性。因此，bEVs正在被探索作为开发针对不同病理状态的免疫治疗策略的创新和有前景的平台。为了建立对bEVs的基础了解，我们首先总结了它们的生物发生、分类、结构和bEVs的生物分子成分。本综述讨论了bEV的生产和改造技术，并探讨了工程bEVs的免疫学特性和作用及其生物医学应用。特别关注先进的工程方法，并概述了工程bEVs开发中的挑战和新兴途径。本综述旨在系统地构建一个基于证据的综合框架，促进工程化bEV的转化优化和临床实施，从而最大限度地发挥其在生物医学领域的应用潜力。

The abundant microbe-associated molecular patterns (MAMPs) and nanoscale structures of bacterial extracellular vesicles (bEVs) collectively facilitate their versatile biological activities. Building on these inherent properties, engineering methods encompassing physical, chemical, and genetic modifications have been strategically employed to enhance the functional diversity of bEVs. Therefore, bEVs are being explored as innovative and promising platforms for developing immunotherapeutic strategies targeting diverse pathological states. To establish a foundational understanding of bEVs, we first summarized their biogenesis, classification, structures and biomolecular constituents of bEVs. This review discusses techniques for bEV production and modification and explores the immunological characteristics and effects of engineered bEVs, along with their biomedical applications. Special attention is devoted to advanced engineering approaches and outlining the challenges and emerging avenues in the development of engineered bEVs. This review aims to systematically construct an evidence-based and comprehensive framework that promotes translational optimization and clinical implementation of engineered bEVs, thereby maximizing their application potential in the biomedical field.