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

The delivery of molecular hydrogen (H) 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 in various inflammatory conditions. However, two critical issues remain unresolved: the unclear mechanism underlying the immunomodulatory effects of H and the lack of precision detection methods to clarify the dose-efficacy relationship in vivo. Since previous reviews focused on developing nanomaterials for H 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 is proposed, the recent detection methods, and the classification and applications of advanced H delivery systems, aiming to enhance the understanding of precision immunomodulation strategies leveraging their properties.