Defect modified zinc oxide with augmenting sonodynamic reactive oxygen species generation

Area of Science:

• Materials Science
• Nanomedicine
• Cancer Therapy

Background:

• Current organic sonosensitizers for sonodynamic therapy (SDT) face limitations in chemical stability, tumor targeting, and therapeutic efficacy.
• Defect engineering and semiconductor catalysis offer promising strategies to overcome these challenges in nanomedicine.

Purpose of the Study:

• To develop a defect-rich zinc oxide (ZnO) based sonosensitizer for enhanced deep tumor eradication via SDT.
• To investigate the role of oxygen defects in improving the sonodynamic performance of ZnO nanostructures.

Main Methods:

• Synthesized gadolinium (Gd)-doped zinc oxide (ZnO) with engineered oxygen defects (D-ZnO_x:Gd).
• Evaluated the sonodynamic performance, including reactive oxygen species (ROS) generation, of D-ZnO_x:Gd under ultrasound irradiation.
• Assessed the anti-tumor efficiency of D-ZnO_x:Gd in a deep breast cancer model.

Main Results:

• The defect-rich D-ZnO_x:Gd exhibited enhanced electron-hole separation due to abundant oxygen defects, boosting the sonodynamic effect.
• D-ZnO_x:Gd demonstrated increased adsorption of water and oxygen molecules, leading to superior ROS production.
• Significant improvements in sonodynamic ROS generation and anti-deep tumor efficacy against breast cancer were observed.

Conclusions:

• Defect engineering in ZnO nanostructures can significantly enhance sonodynamic therapy efficacy.
• D-ZnO_x:Gd represents a promising semiconductor nanoagent for efficient deep tumor sonodynamic eradication.
• This study provides mechanistic insights into oxygen deficiency-mediated enhancement of ZnO sonodynamic activity and highlights defect engineering for cancer therapy.