Manganese Oxide Nanomaterials: Synthesis, Properties, and Theranostic Applications

Abstract

Despite the comprehensive applications in bioimaging, biosensing, drug/gene delivery, and tumor therapy of manganese oxide nanomaterials (MONs including MnO2, MnO, Mn2O3, Mn3O4, and MnOx) and their derivatives, a review article focusing on MON‐based nanoplatforms has not been reported yet. Herein, the representative progresses of MONs on synthesis, heterogene, properties, surface modification, toxicity, imaging, biodetection, and therapy are mainly introduced. First, five kinds of primary synthetic methods of MONs are presented, including thermal decomposition method, exfoliation strategy, permanganates reduction method, adsorption–oxidation method, and hydro/solvothermal. Second, the preparations of hollow MONs and MON‐based composite materials are summarized specially. Then, the chemical properties, surface modification, and toxicity of MONs are discussed. Next, the diagnostic applications including imaging and sensing are outlined. Finally, some representative rational designs of MONs in photodynamic therapy, photothermal therapy, chemodynamic therapy, sonodynamic therapy, radiotherapy, magnetic hyperthermia, chemotherapy, gene therapy, starvation therapy, ferroptosis, immunotherapy, and various combination therapy are highlighted.

MnOx Nanospikes as Nanoadjuvants and Immunogenic Cell Death Drugs with Enhanced Antitumor Immunity and Antimetastatic Effect

“…[4] Over the past two decades, manganese oxide nanomaterials (MONs) have drawn attention in biomedical applications. [5] For example, He et al developed honeycomb MnO 2based nanoplatforms for intracellular glutathione (GSH)triggered drug release and photodynamic/gene-silencing dual therapy. [6] Despite these discoveries, the intrinsic immunogenicity and potential immune response of MONs remain unclear.…”

Advances in Hollow Inorganic Nanomedicines for Photothermal-Based Therapies

“…Manganese oxide, an excellent MRI contrast agent, has been widely used in MRI. 66 In 2008, An et al designed hollow manganese oxide (MnO) NPs of different sizes for use in MRI. 67 The authors found that the T 1 relaxation was enhanced with increasing surface area, and that the hollow structures had a drug-loading capacity.…”

Bacterial Template Synthesis of Multifunctional Nanospindles for Glutathione Detection and Enhanced Cancer-Specific Chemo-Chemodynamic Therapy

“…To date, several synthetic strategies have been proposed to prepare MnO x -based nanomaterials with different sizes and morphologies, including the thermal decomposition method [61], exfoliation strategy [62], adsorption-oxidation method [63,64], hydro-/solvothermal method [65], and permanganate reduction method [66,67]. These methods show their intrinsic advantages and disadvantages [68]. For example, the thermal decomposition strategy can precisely regulate the particle size and morphology but the oily solventcapping surface limits the biomedical applications of the products.…”