锰（Mn）是一种人体必需的无机微量营养元素，由于它在氧化调节和其他生理过程中的重要作用，是动物体内多种生理过程所必需的。此外，锰离子（Mn2+）已被广泛报道为调节不同免疫反应的关键因素，因此具有成为潜在的辅助剂和免疫治疗剂的前景。利用锰的生物和免疫活性优势，氧化锰纳米颗粒（MnO2 NPs）是一种新型无机纳米材料，具有简单制备、低成本、环境友好、低毒性、可生物降解代谢和高生物利用性等多种优点。作为一种药物载体，MnO2 NPs还表现出在酸性条件下催化过氧化氢（H2O2）产生氧气（O2）的能力，从而通过重塑肿瘤微环境增强放疗、化疗和其他治疗手段的疗效。更重要的是，MnO2 NPs在固有和适应性免疫中发挥重要的免疫调节作用。在本文中，我们总结了锰的生物活性，并介绍了MnO2 NPs的生物和医学功能及其机制。此外，我们着重讨论了MnO2 NPs的免疫调节效应和机制，以及它们作为辅助剂和免疫调节剂的潜力，这可能有助于开发更有效的疾病控制的新型疫苗和免疫治疗方法。版权所有©2023黄、阮、马、陈、张、范、林、黄、卢、徐、皮和郑。

Manganese (Mn), a nutrient inorganic trace element, is necessary for a variety of physiological processes of animal body due to their important roles in oxidative regulation effects and other aspects of activities. Moreover, manganese ion (Mn2+) has widely reported to be crucial for the regulations of different immunological responses, thus showing promising application as potential adjuvants and immunotherapeutics. Taking the advantages of Mn-based biological and immunological activities, Manganese dioxide nanoparticles (MnO2 NPs) are a new type of inorganic nanomaterials with numerous advantages, including simple preparation, low cost, environmental friendliness, low toxicity, biodegradable metabolism and high bioavailability. MnO2 NPs, as a kind of drug carrier, have also shown the ability to catalyze hydrogen peroxide (H2O2) to produce oxygen (O2) under acidic conditions, which can enhance the efficacy of radiotherapy, chemotherapy and other therapeutics for tumor treatment by remodeling the tumor microenvironment. More importantly, MnO2 NPs also play important roles in immune regulations both in innate and adaptive immunity. In this review, we summarize the biological activities of Manganese, followed by the introduction for the biological and medical functions and mechanisms of MnO2 NPs. What's more, we emphatically discussed the immunological regulation effects and mechanisms of MnO2 NPs, as well as their potentials to serve as adjuvants and immunomodulators, which might benefit the development of novel vaccines and immunotherapies for more effective disease control.Copyright © 2023 Huang, Ruan, Ma, Chen, Zhang, Fan, Lin, Huang, Lu, Xu, Pi and Zheng.