Tannic acid-mediated synthesis of flower-like mesoporous MnO₂ nanostructures as T₁-T₂ dual-modal MRI contrast agents and dual-enzyme mimetic agents.

ABSTRACT: This study introduces a simple method for preparing a new generation of MnO₂ nanomaterials (MNMs) using tannic acid as a template. Two shapes of MnO₂ NMs, flower-like M1-MnO₂ and near-spherical M2-MnO₂, were prepared and compared as dual-active nanozymes and contrast agents in magnetic resonance imaging (MRI). Various parameters, including the crystallinity, morphology, magnetic saturation (M_s), surface functionality, surface area, and porosity of the MNMs were investigated. Flower-like M1-MnO₂ NMs were biocompatible and exhibited pH-sensitive oxidase and peroxidase mimetic activity, more potent than near-spherical M2-MnO₂. Furthermore, the signal intensity and r₁ relaxivity strongly depended on the crystallinity, morphology, pore size, and specific surface area of the synthesized MNMs. Our findings suggest that flower-like M1-MnO₂ NM with acceptable dual-enzyme mimetic (oxidase-like and peroxidase-like) and T₁ MRI contrast activities could be employed as a promising theranostic system for future purposes.

SUBMITTER: Sorouri F 

PROVIDER: S-EPMC10480446 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature