Defect-Rich 2D Layered Double Hydroxides Enhance Sonodynamic Antibacterial Therapy

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Sonodynamic therapy (SDT) offers a non-invasive approach to combat antibiotic-resistant bacteria.
• Current sonosensitizers often exhibit limited reactive oxygen species (ROS) generation under ultrasound (US) irradiation.
• Layered double hydroxides (LDHs) possess tunable properties and good biocompatibility, but their application in SDT for antibacterial purposes is underexplored.

Purpose of the Study:

• To develop a novel defect-rich 2D layered double hydroxide (DR-LDH) material for enhanced sonodynamic antibacterial therapy.
• To investigate the impact of defect engineering and phase transition on the electronic structure and ROS generation of ZnCuW-LDH nanosheets.
• To validate the in vitro and in vivo antibacterial efficacy of the engineered DR-ZnCuW-LDH nanosheets under ultrasound irradiation.

Main Methods:

• Fabrication of defect-rich 2D DR-ZnCuW-LDH nanosheets using a facile acid-etching method at ambient conditions.
• Characterization of the phase transition, defect formation (oxygen vacancies), and bandgap narrowing (from 3.29 to 1.80 eV) using advanced analytical techniques.
• Evaluation of ROS generation enhancement under ultrasound irradiation compared to pristine ZnCuW-LDH.
• In vitro and in vivo antibacterial efficacy testing of DR-ZnCuW-LDH nanosheets under US exposure.

Main Results:

• The acid-etching method successfully produced defect-rich DR-ZnCuW-LDH nanosheets with a crystalline-to-polycrystalline phase transition.
• Engineered nanosheets exhibited significantly narrowed bandgaps and improved electron-hole separation due to introduced defects and oxygen vacancies.
• DR-ZnCuW-LDH demonstrated a fourfold increase in ROS generation under US irradiation compared to pristine LDH.
• Both in vitro and in vivo studies confirmed the exceptional antibacterial efficacy of DR-ZnCuW-LDH under SDT.

Conclusions:

• Defect engineering via acid-etching is an effective strategy to enhance the sonodynamic performance of LDHs.
• The developed DR-ZnCuW-LDH nanosheets show great promise as efficient inorganic sonosensitizers for combating antibiotic-resistant infections.
• This work establishes a versatile platform for advanced sonodynamic antibacterial applications.