ROS scavenging Manganese-loaded mesoporous silica nanozymes for catalytic anti-inflammatory therapy

Reactive oxygen species (ROS) are reactive substances closely related to the inflammatory response, and previous studies have shown that anti-inflammatory therapy can achieve significant effects by scavenging ROS. Nanozymes are synthetic mimics of natural enzymes that are more stable, customizable, inexpensive, and catalytic for ROS. Therefore, we prepared a novel manganese-loaded mesoporous silica nanozyme (MnMSN) by template method and KMnO₄ oxidation surfactant templates. The physicochemical properties of the nanomaterials were investigated by XRD, TEM, SEM, size, Zeta potential and BET, etc. The results showed that MnMSN contains MnO₂ (Mn⁴⁺) and MnSiO₃ (Mn²⁺), and the particle size of MnMSN is smaller with the increase of KMnO₄ oxidation surfactant templates time, and the in vitro scavenging of ROS (H₂O₂, ·OH and ·O₂^–) is more effective. MnMSN has good cytocompatibility, scavenging intracellular ROS and inducing a shift from M1 to anti-inflammatory M2 phenotype. Furthermore, the intrinsic mechanism of MnMSN regulation of macrophage polarization was investigated by ELISA and qPCR, and the results showed that MnMSN is through scavenging ROS, leading to the down-regulation of NF-κB, which further leads to the down-regulation of TNF-α and IL-Iβ. The results of this work highlight the potential of MnMSN in catalyzing anti-inflammatory therapy.