Functionalized Mn3 O4 Nanosheets with Photothermal, Photodynamic, and Oxidase-Like Activities Triggered by Low-Powered Near-Infrared Light for Synergetic Combating Multidrug-Resistant Bacterial Infections

Adv Healthc Mater. 2022 Jun;11(12):e2200121. doi: 10.1002/adhm.202200121. Epub 2022 Feb 26.

Abstract

Multidrug-resistant (MDR) pathogenic bacterial infections have become a major danger to public health. Synergetic therapy through multiple approaches is more powerful than the respective one alone, but has been rarely achieved in defeating MDR bacterial infections so far. Herein, indocyanine green-functionalized Mn3 O4 nanosheets are engineered as an efficient and safe antibacterial agent with photothermal, photodynamic, and oxidase-like activities, which display powerful ability in treating MDR bacterial infections. Therein, photothermal and photodynamic activities can be triggered by a single low-powered near-infrared laser (808 nm, 0.33 W cm-2 ), resulting in the generation of localized hyperthermia (photothermal conversion efficiency, 67.5%) and singlet oxygen. Meanwhile, oxidase-like activity of this material further leads to the generation of hydroxyl radical as well as superoxide radical. Sheet-like structure with rough surfaces make them tends to adhere on bacterial surface and thus damage membrane system as well as influence bacterial metabolism. As a result, Gram-positive and Gram-negative bacteria can both be eradicated. Animal experiments further indicate that the functionalized Mn3 O4 nanosheets can effectively treat methicillin-resistant Staphylococcus aureus-infected wounds through the triple synergetic therapy. Moreover, toxicity evaluation in vitro and in vivo has proved the superior biosafety of this material, which is promising to apply in clinical anti-infective therapy.

Keywords: antibacterial; manganese oxide; nanozymes; photothermal; reactive oxygen species; synergetic therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Infections* / therapy
  • Drug Resistance, Multiple, Bacterial*
  • Gram-Negative Bacteria
  • Gram-Positive Bacteria
  • Hyperthermia, Induced* / methods
  • Infrared Rays*
  • Methicillin-Resistant Staphylococcus aureus
  • Nanostructures
  • Oxidoreductases / pharmacology

Substances

  • Anti-Bacterial Agents
  • Oxidoreductases