Cerium oxide nanoparticles (&lt;5 nm) are redox-active agents with exciting uses in biological systems. Their mixed-valence state (Ce3+ and Ce4+) allows them to mimic SOD, peroxidase, and catalase to remove reactive oxygen species (ROS; H2O2, OH-, and O2-) associated with inflammation and cell death. Albumin-nanoceria, ceria nanoparticles coated in albumin proteins, in particular exhibit powerful anti-inflammatory effects. Albumin-nanoceria effectively decreases pro-inflammatory M1 and increases anti-inflammatory M2 macrophages through efficient ROS scavenging. In this study, we aim to determine the effect of catalysts during synthesis on the Ce3+/Ce4+ ratios of albumin-nanoceria. We also aim to determine how the particles with different ratios of Ce3+/Ce4+ can alter the polarization of macrophages. Albumin-nanoceria were synthesized via biomineralization in the presence of hydrogen peroxide or ammonium hydroxide. The crystallinity and morphology of the particles were characterized by transmission electron microscopy (TEM). The valence states of the particles were determined using X-ray photoelectron spectroscopy (XPS). We were able to quantify the anti-inflammatory effects of each particle variant by measuring CD80 and CD206, which indicate M1-like pro-inflammatory and M2-like anti-inflammatory behavior, respectively, on the particle treated Raw 264.7 cells. Finally, we found surface valence of albumin-nanoceria can be manipulated by choice of catalyst during synthesis, and the particles with elevated Ce3+/Ce4+ exhibited enhanced anti-inflammatory efficacy.

Catalyst-dependent synthesis of albumin-nanoceria to control particle valence state and macrophage differentiation

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.