摘要
The particular physicochemical properties of nanomaterials are able to elicit unique biological responses. The property activity relationship is usually established for in-depth understanding of toxicity mechanisms and designing safer nanomaterials. In this study, the toxic role of specific crystallographic facets of a series of polyhedral lead sulfide （PbS） nanocrystals, including truncated octahedrons, cuboctahedrons, truncated cubes, and cubes, was investigated in human bronchial epithelial cells （BEAS-2B） and murine alveolar macrophages （RAW 264.7） cells./100} facets were found capable of triggering facet-dependent cellular oxidative stress and heavy metal stress responses, such as glutathione depletion, lipid peroxidation, reactive oxygen species （ROS） production, heme oxygenase-1 （HO-1） and metallothionein （MT） expression, and mitochondrial dysfunction, while {111} facets remained inert under biological conditions. The {100}-facet-dependent toxicity was ascribed to {100}-facet-dependent lead dissolution, while the low lead dissolution of {111} facets was due to the strong protection afforded by poly（vinyl pyrrolidone） during synthesis. Based on this facet-toxicity relationship, a ＂safe-by-design＂ strategy was designed to prevent lead dissolution from {100} facets through the formation of atomically thin lead-chloride adlayers, resulting in safer polyhedral PbS nanocrystals.
The particular physicochemical properties of nanomaterials are able to elicit unique biological responses. The property activity relationship is usually established for in-depth understanding of toxicity mechanisms and designing safer nanomaterials. In this study, the toxic role of specific crystallographic facets of a series of polyhedral lead sulfide （PbS） nanocrystals, including truncated octahedrons, cuboctahedrons, truncated cubes, and cubes, was investigated in human bronchial epithelial cells （BEAS-2B） and murine alveolar macrophages （RAW 264.7） cells./100} facets were found capable of triggering facet-dependent cellular oxidative stress and heavy metal stress responses, such as glutathione depletion, lipid peroxidation, reactive oxygen species （ROS） production, heme oxygenase-1 （HO-1） and metallothionein （MT） expression, and mitochondrial dysfunction, while {111} facets remained inert under biological conditions. The {100}-facet-dependent toxicity was ascribed to {100}-facet-dependent lead dissolution, while the low lead dissolution of {111} facets was due to the strong protection afforded by poly（vinyl pyrrolidone） during synthesis. Based on this facet-toxicity relationship, a ＂safe-by-design＂ strategy was designed to prevent lead dissolution from {100} facets through the formation of atomically thin lead-chloride adlayers, resulting in safer polyhedral PbS nanocrystals.
基金
This work was primarily supported by the National Natural Science Foundation of China （Nos. 21573216 and 21501170）, Hundred Talent Program of CAS, Science and Technology Development Project Foundation of Jilin Province （Nos. 20160101304JC and 20160520134JH）, Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry, the Start-up fund from Changchun Institute of Applied Chemistry, CAS, and Talent Development fund of Jilin, China.
