Physicochemical origin for free radical generation of iron oxide nanoparticles in biomicroenvironment: Catalytic activities mediated by surface chemical states

Bing Wang, Jun Jie Yin, Xiaoyan Zhou, Ibrahim Kurash, Zhifang Chai, Yuliang Zhao, Weiyue Feng

Research output: Contribution to journalArticlepeer-review

100 Scopus citations

Abstract

A wide range of nanoparticles (NPs) have been found to generate free radicals in biological systems. Hence, it is hypothesized that free radical generation may play a key role in the mechanism of nanomaterial toxicity in vivo. However, the main physicochemical basis for the free radical generation particularly in the biomicroenvironment has not yet been fully established. In this study, we performed comprehensive spectroscopic techniques to probe the physicochemical origin of free radical generation induced by iron oxide nanoparticles in biomicroenvironment. We demonstrated that α-Fe 2O3 and γ-Fe2O3 NPs induced hydroxyl radical (OH) via homogeneous and heterogeneous Fenton process, depending on the biological microenvironment of pH and reducing agent presence. The physicochemical structures such as chemical states of oxygen and iron on nanosurface are the key factors in the homogeneous and heterogeneous catalytic reactions. A noteworthy finding was that in situ surface reduction of Fe2O3 NPs occurred in the presence of a physiological amount of biological reducing agents (l-cysteine or NADPH), which could enhance and even reverse the capacity of OH generation by α-Fe2O3 and γ-Fe2O3 NPs under low pH 1.2 condition. The present study demonstrates that exploration of the physicochemical basis at the nanobio interface in biomicroenvironments may help to understand the mechanism of nanotoxicity and guide safe design of nanomaterials for biomedical application

Original languageEnglish (US)
Pages (from-to)383-392
Number of pages10
JournalJournal of Physical Chemistry C
Volume117
Issue number1
DOIs
StatePublished - Jan 10 2013

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

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