title: Carboxymethyl cellulose coating decreases toxicity and oxidizing capacity of nanoscale zerovalent iron.
abstract: Nanoscale zerovalent iron (NZVI) with modified surface via coating with organic stabilizers has been documented with enhanced colloidal stability and dispersity. Therefore, the expanded application potential and accompanying intrinsic exposure of such nanoparticle can be anticipated. In our study, carboxymethyl cellulose (CMC)-stabilized NZVI (CNZVI) exerted minimized oxidative stress response and slower disruption of cell membrane integrity, resulting in mitigated cytotoxicity towards bacteria Agrobacterium sp. PH-08 as compared with the uncoated counterpart. The corrosive oxidation of both nanoparticles in oxygenic water provided a better understanding of coating effect. The decreased oxidative degradation of probe 4-chlorophenol with CNZVI than NZVI implicated a weaker oxidizing capacity, which might overweight massive adhesion-mediated redox damage and explain the different exposure outcome. However, enhanced evolution of iron oxide as well as the promoted production of hydrogen peroxide adversely demonstrated CMC-coating facilitated iron corrosion by oxygen, suggesting CMC was most likely to act as a radical scavenger and compete with organics or bacteria for oxidants. Moreover, XRD, XPS and TEM results showed that the spherical NZVI was oxidized to form needle-shaped iron oxide-hydroxide (γFeOOH) with no detectable oxidative stress for PH-08, alleviating worries regarding exotoxicological impact of iron nanotechnology.
authors.affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhou
authors.affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea.
authors.forename: Thao Le
authors.initials: TL
authors.lastname: Thanh
authors.affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea.
authors.forename: Jianyu
authors.initials: J
authors.lastname: Gong
authors.affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea.
authors.forename: Jae-Hwan
authors.initials: JH
authors.lastname: Kim
authors.affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea.
authors.forename: Eun-Ju
authors.initials: EJ
authors.lastname: Kim
authors.affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea. Electronic address: yschang@postech.ac.kr.
authors.forename: Yoon-Seok
authors.initials: YS
authors.lastname: Chang
mesh_terms: D060054:Agrobacterium / Q000166:cytology / Q000187:drug effects*; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry / Q000633:toxicity*; D002733:Chlorophenols / Q000737:chemistry; D003343:Corrosion; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry / Q000633:toxicity*; D053758:Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D036103:Nanotechnology / Q000379:methods; D016877:Oxidants / Q000737:chemistry / Q000633:toxicity*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects
chemical_list: D002733:Chlorophenols; D016877:Oxidants; C029107:4-chlorophenol; D006861:Hydrogen Peroxide; D007501:Iron; D002266:Carboxymethylcellulose Sodium
keywords: Carboxymethyl cellulose; Nanoscale zerovalent iron; Nanotoxicity; Reactivity