Defect-rich nickel-doped ceria nanozymes for ROS-mediated antibacterial therapy

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Ceria (CeO₂) nanoparticles exhibit promising catalytic properties.
• Developing effective antimicrobial agents is crucial for combating bacterial infections.
• Nickel doping can enhance the defect concentration and catalytic activity of ceria.

Purpose of the Study:

• To synthesize defect-rich nickel-doped ceria (Ni-CeO₂) nanocomposites.
• To evaluate the enhanced reactive oxygen species (ROS)-mediated antibacterial activity of Ni-CeO₂.
• To investigate the potential of Ni-CeO₂ as an antimicrobial nanozyme platform.

Main Methods:

• Ni-CeO₂ nanocomposites synthesized via reduction of Ni²⁺ on ceria nanopowder.
• Characterization using XRD, Raman, TEM, EDX, and XPS.
• Evaluation of pro-oxidative mimic activity, ROS generation, antibacterial efficacy against E. coli and S. aureus, and in vitro cytotoxicity.

Main Results:

• Nickel doping increased defects, oxygen vacancies, and Ce³⁺/Ce⁴⁺ redox cycling, enhancing pro-oxidative mimic activity.
• Ni-CeO₂ nanozymes demonstrated significant reduction of E. coli (82.11%) and S. aureus (78.58%) at 100 µM H₂O₂.
• Cytotoxicity studies confirmed biocompatibility at effective antibacterial concentrations.

Conclusions:

• Defect-rich Ni-CeO₂ nanocomposites exhibit enhanced ROS-mediated antibacterial activity.
• Ni-CeO₂ represents a promising antimicrobial nanozyme platform for treating bacterial infections.
• The enhanced catalytic activity and biocompatibility support its therapeutic potential.