A Magnetically Responsive Selenium-Doped CeO₂ Nanozyme for On-Demand Reactive Oxygen Species Modulation and Enhanced...

Area of Science:

• Biomaterials Science
• Nanotechnology
• Regenerative Medicine

Background:

• Precise control of reactive oxygen species (ROS) is crucial for effective tissue repair.
• Inorganic nanozymes like cerium dioxide (CeO2) show promise but lack adaptable ROS-scavenging activity.
• Existing nanozymes cannot dynamically adjust to the changing immune microenvironment during healing.

Purpose of the Study:

• To develop a magnetically responsive dynamic antioxidant system for on-demand ROS modulation.
• To engineer cerium dioxide (CeO2) nanozymes with enhanced and tunable catalytic activity.
• To investigate the system's efficacy in promoting tissue regeneration in cartilage and skin defect models.

Main Methods:

• Engineered selenium (Se)-doped cerium dioxide (CeO2) nanoparticles to increase oxygen vacancies (Vo) and intrinsic antioxidant activity.
• Utilized a static magnetic field (SMF) to further amplify the catalytic efficiency of Se-CeO2.
• Loaded Se-CeO2 into a sodium alginate-hyaluronic acid hydrogel (SCSH-Gel) for in vitro and in vivo testing.
• Assessed macrophage polarization, chondrocyte and fibroblast protection from oxidative stress, neocartilage formation, and skin wound re-epithelialization.

Main Results:

• Se-doping significantly enhanced the intrinsic ROS-scavenging capacity of CeO2 by engineering oxygen vacancies.
• Static magnetic field (SMF) application further amplified the catalytic efficiency of Se-CeO2 nanozymes.
• Se-CeO2 under SMF promoted M2 macrophage polarization, protected cells from oxidative stress, and accelerated neocartilage formation and skin wound healing in vivo.

Conclusions:

• Selenium doping and magnetic actuation provide a versatile strategy to dynamically modulate ROS homeostasis using inorganic nanozymes.
• This approach enables precise programming of the microenvironment, offering a promising method for facilitating tissue regeneration.
• The developed Se-CeO2-based system demonstrates significant potential for applications in regenerative medicine and wound healing.