Molecular Imaging Investigations of Polymer-Coated Cerium Oxide Nanoparticles as a Radioprotective Therapeutic Candidate

Cerium oxide nanoparticles (CONPs) have a unique surface redox chemistry that appears to selectively protect normal tissues from radiation induced damage. Our prior research exploring the biocompatibility of polymer-coated CONPs found further study poly-acrylic acid (PAA)-coated was warranted due improved systemic biodistribution and rapid renal clearance. This work explores PAA-CONPs’ radioprotective efficacy mechanism action related tumor microenvironment pH. An ex vivo TUNEL assay used measure protection irradiated mouse colon in comparison established radioprotector amifostine. [18F]FDG PET imaging spontaneous tumors utilized determine effects PAA-CONPs on response. In MRI an clonogenic were pH radioprotection tumor-bearing mice. showed excellent equivalent uncoated do not affect response radiation. Normalization allowed some by PAA-CONPs, which may explain their lack acidic microenvironment. Overall, meet criteria for clinical application as therapeutic agent are candidate study.