title: PEGylated nanoceria as radical scavenger with tunable redox chemistry.
abstract: We report the direct synthesis of cerium oxide nanoparticles (CNPs) in polyethylene glycol (PEG) based solutions with efficient radical scavenging properties. Synthesis of CNPs in PEG demonstrated a concentration dependent (of PEG) redox activity characterized by UV-visible spectroscopy. PEGylated CNPs acted as efficient radical scavengers, and superoxide dismutase (SOD) activity of CNPs synthesized in various concentration of PEG did not reduce compared to bare nanoceria. In addition to superoxide, PEGylated nanoceria demonstrated quenching of peroxide radicals as well. It was observed that the reaction with hydrogen peroxide leads to the formation of a charge transfer complex governed by the concentration of PEG. The stability of the charge transfer complex provides the tunable oxidation state of CNPs. The stability of this complex influences the regenerative capacity of the active 3+ oxidation state of CNPs. The cell viability as well as SOD activity of PEGylated CNPs is compared to those of bare CNPs, and the differences are outlined.
authors.affiliation: Advanced Materials Processing and Analysis Centre, University of Central Florida, Orlando, Florida 32816, USA. karakoti@mail.ucf.edu
authors.forename: Ajay S
authors.initials: AS
authors.lastname: Karakoti
authors.forename: Sanjay
authors.initials: S
authors.lastname: Singh
authors.forename: Amit
authors.initials: A
authors.lastname: Kumar
authors.forename: Maura
authors.initials: M
authors.lastname: Malinska
authors.forename: Satyanarayana V N T
authors.initials: SV
authors.lastname: Kuchibhatla
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Wozniak
authors.forename: William T
authors.initials: WT
authors.lastname: Self
authors.forename: Sudipta
authors.initials: S
authors.lastname: Seal
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D002563:Cerium / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000138:chemical synthesis / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D011092:Polyethylene Glycols / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013482:Superoxide Dismutase / Q000737:chemistry; D013481:Superoxides / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D016166:Free Radical Scavengers; D013481:Superoxides; D002563:Cerium; D011092:Polyethylene Glycols; C030583:ceric oxide; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase