title: Facet Energy versus Enzyme-like Activities: The Unexpected Protection of Palladium Nanocrystals against Oxidative Damage.
abstract: To develop nanomaterials as artificial enzymes, it is necessary to better understand how their physicochemical properties affect their enzyme-like activities. Although prior research has demonstrated that nanomaterials exhibit tunable enzyme-like activities depending on their size, structure, and composition, few studies have examined the effect of surface facets, which determine surface energy or surface reactivity. Here, we use electron spin-resonance spectroscopy to report that lower surface energy {111}-faceted Pd octahedrons have greater intrinsic antioxidant enzyme-like activity than higher surface energy {100}-faceted Pd nanocubes. Our in vitro experiments found that those same Pd octahedrons are more effective than Pd nanocubes at scavenging reactive oxygen species (ROS). Those reductions in ROS preserve the homogeneity of mitochondrial membrane potential and attenuate damage to important biomolecules, thereby allowing a substantially higher number of cells to survive oxidative challenges. Our computations of molecular mechanisms for the antioxidant activities of {111}- and {100}-faceted Pd nanocrystals, as well as their activity order, agree well with experimental observations. These findings can guide the design of antioxidant-mimicking nanomaterials, which could have therapeutic or preventative potential against oxidative stress related diseases.
authors.affiliation: School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University , Suzhou 215123, China.|Division of Bioanalytical Chemistry and Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , College Park, Maryland 20740, United States.
authors.forename: Cuicui
authors.initials: C
authors.lastname: Ge
authors.affiliation: School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University , Suzhou 215123, China.
authors.forename: Ge
authors.initials: G
authors.lastname: Fang
authors.affiliation: College of Chemistry and Chemical Engineering, Jiangxi Normal University , Nanchang 330022, China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Shen
authors.affiliation: School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University , Suzhou 215123, China.|Division of Bioanalytical Chemistry and Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , College Park, Maryland 20740, United States.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chong
authors.affiliation: Division of Bioanalytical Chemistry and Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , College Park, Maryland 20740, United States.
authors.forename: Wayne G
authors.initials: WG
authors.lastname: Wamer
authors.affiliation: College of Chemistry and Chemical Engineering, Jiangxi Normal University , Nanchang 330022, China.
authors.forename: Xingfa
authors.initials: X
authors.lastname: Gao
authors.affiliation: School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University , Suzhou 215123, China.
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Chai
authors.affiliation: Key Laboratory For Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology of China and Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Chunying
authors.initials: C
authors.lastname: Chen
authors.affiliation: Division of Bioanalytical Chemistry and Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , College Park, Maryland 20740, United States.
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Yin
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D053758:Nanoparticles; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D010165:Palladium; D017382:Reactive Oxygen Species
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D010165:Palladium
keywords: antioxidants; computational chemistry; enzyme-like activity; oxidative stress; palladium nanocrystals; surface facet