Hollow manganese dioxide-chitosan hydrogel for the treatment of atopic dermatitis through inflammation-suppression and ROS scavenging

Atopic dermatitis (AD) is a chronic inflammatory disease associated with immune dysfunction. High levels of reactive oxygen species (ROS) can lead to oxidative stress, release of pro-inflammatory cytokines, and T-cell differentiation, thereby promoting the onset and worsening of AD. In this study, we innovatively used quaternary ammonium chitosan (QCS) and tannic acid (TA) as raw materials to design and prepare a therapeutic hydrogel(H-MnO 2 -Gel) loaded with hollow manganese dioxide nanoparticles (H-MnO 2 NPs). In this system, the hydrogel is mainly cross-linked by dynamic ion and hydrogen bonding between QCS and TA, resulting in excellent moisture retention properties. Moreover, due to the inherent antioxidant properties of QCS/TA, as well as the outstanding H 2 O 2 scavenging ability of H-MnO 2 NPs, the hydrogel exhibits significant ROS scavenging capability. In vitro experiments have shown that H-MnO 2 -Gel exhibits good cellular biocompatibility. Importantly, in an AD-induced mouse model, H-MnO 2 -Gel significantly enhanced therapeutic effects by reducing epidermal thickness, mast cell number, and IgE antibodies. These findings suggest that H-MnO 2 -Gel, by effectively clearing ROS and regulating the inflammatory microenvironment, provides a promising approach for the treatment of AD.