Wet/Sono‐Chemical Synthesis of Enzymatic Two‐Dimensional MnO₂ Nanosheets for Synergistic Catalysis‐Enhanced Phototheranostics

Abstract

Abstract2D nanomaterials have attracted broad interest in the field of biomedicine owing to their large surface area, high drug‐loading capacity, and excellent photothermal conversion. However, few studies report their “enzyme‐like” catalytic performance because it is difficult to prepare enzymatic nanosheets with small size and ultrathin thickness by current synthetic protocols. Herein, a novel one‐step wet‐chemical method is first proposed for protein‐directed synthesis of 2D MnO2 nanosheets (M‐NSs), in which the size and thickness can be easily adjusted by the protein dosage. Then, a unique sono‐chemical approach is introduced for surface functionalization of the M‐NSs with high dispersity/stability as well as metal‐cation‐chelating capacity, which can not only chelate 64Cu radionuclides for positron emission tomography (PET) imaging, but also capture the potentially released Mn2+ for enhanced biosafety. Interestingly, the resulting M‐NS exhibits excellent enzyme‐like activity to catalyze the oxidation of glucose, which represents an alternative paradigm of acute glucose oxidase for starving cancer cells and sensitizing them to thermal ablation. Featured with outstanding phototheranostic performance, the well‐designed M‐NS can achieve effective photoacoustic‐imaging‐guided synergistic starvation‐enhanced photothermal therapy. This study is expected to establish a new enzymatic phototheranostic paradigm based on small‐sized and ultrathin M‐NSs, which will broaden the application of 2D nanomaterials.

Advances in nanomedicine for cancer starvation therapy

“…In another work, Tang et al . developed a novel BSA-directed two-dimensional (2D) MnO 2 nanosheet (M-NS) by one-step method 122. This M-NS not only owned an excellent GOx-like activity for catalyzing the local glucose oxidation, but also exhibited high photothermal conversion efficiency due to the large surface area.…”

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].…”

Recent advancements in two‐dimensional nanomaterials for drug delivery

“…(c) The as demonstrated intracellular starvation‐enhanced PTT behavior. (Reprinted with permission from Tang et al (). Copyright 2019 Wiley VCH).…”