Delivery of Molecular Hydrogen for Precision Immunomodulation: Mechanisms, Detection Methods, and Applications

Abstract The delivery of molecular hydrogen (H ₂ ) is increasingly recognized for its potential in precision immunomodulation, primarily through multiple pathways such as antioxidant action, modulation of inflammatory factors, and inhibition of apoptosis. These effects contribute to a balanced and functional immune system, highlighting the therapeutic promise of H ₂ in various inflammatory conditions. However, two critical issues remain unresolved: the unclear mechanism underlying the immunomodulatory effects of H ₂ and the lack of precision detection methods to clarify the dose‐efficacy relationship in vivo. Since previous reviews focused on developing nanomaterials for H ₂ delivery, they often overlook analyses of the immunomodulation mechanisms and fail to update the detection methods. To address these gaps, a review that explores the immunomodulatory mechanisms of H ₂ is proposed, the recent detection methods, and the classification and applications of advanced H ₂ delivery systems, aiming to enhance the understanding of precision immunomodulation strategies leveraging their properties.