A comparative study on surface-engineered nanoceria using a catechol copolymer design: colloidal stability vs....

Area of Science:

• Nanomaterials Science
• Biomaterials Engineering
• Catalysis

Background:

• Nanoceria (NC) are potent nanozyme antioxidants but exhibit poor colloidal stability in biological environments.
• The relationship between nanoceria colloidal stability and antioxidant efficacy remains underexplored.

Purpose of the Study:

• To engineer the surface of nanoceria using novel copolymeric stabilising agents.
• To investigate the impact of surface modification on nanoceria colloidal stability and antioxidant activity.

Main Methods:

• Synthesis of three copolymeric stabilising agents with poly(oligo(ethylene glycol) methyl ether methacrylate) (P(OEGMA)) brushes and catechol anchoring blocks.
• Surface engineering of NC with these agents.
• Assessment of colloidal stability in PBS using UV-Vis spectrophotometry.
• Analysis of catalase (CAT)- and superoxide dismutase (SOD)-like activities using fluorospectrophotometry.
• Characterization of surface changes using X-ray photoelectron spectroscopy (XPS).

Main Results:

• P(OEGMA) coating significantly enhanced NC colloidal stability for over 48 hours.
• Catechol functionalities promoted stable NC attachment and increased the Ce³⁺/Ce⁴⁺ ratio and oxygen vacancy concentration.
• Surface-engineered NC showed a 41% increase in CAT-like activity and a 78% increase in SOD-like activity compared to bare NC.

Conclusions:

• Surface engineering with P(OEGMA) and catechol blocks effectively improves nanoceria colloidal stability.
• Enhanced colloidal stability correlates positively with increased antioxidant activity (CAT and SOD-like).
• Optimized surface modification offers a promising strategy for developing stable and highly active nanoceria nanozymes.