title: Cytotoxicity of amorphous silica particles against macrophage-like THP-1 cells depends on particle-size and surface properties.
abstract: Recent studies have indicated that amorphous silica particles (SPs) show cytotoxicity against various types of cells, including macrophages. However, the mechanism of cell death has not been determined, and systematic investigations of the relationship between particle characteristics and cytotoxicity are still quite limited. Here, we compared the cytotoxicity of SPs of various sizes (30-1000 nm) and surface properties against differentiated THP-1 human macrophage-like cells. We found that 300 and 1000 nm SPs showed cytotoxicity against THP-1 cells, whereas 30, 50, and 70 nm SPs did not induce cell death. We demonstrated that 1000 nm SP showed strong cytotoxicity that depended on reactive oxygen species but was independent of caspases. Furthermore, we showed that surface modification of 1000 nm SPs dramatically suppressed their cytotoxicity. Our results suggest that systematic evaluation of the association between particle characteristics and biological effects is necessary for the creation of safe SPs.
authors.affiliation: Laboratory of Biotechnology and Therapeutics, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Morishige
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshioka
authors.forename: H
authors.initials: H
authors.lastname: Inakura
authors.forename: A
authors.initials: A
authors.lastname: Tanabe
authors.forename: X
authors.initials: X
authors.lastname: Yao
authors.forename: S
authors.initials: S
authors.lastname: Tsunoda
authors.forename: Y
authors.initials: Y
authors.lastname: Tsutsumi
authors.forename: Y
authors.initials: Y
authors.lastname: Mukai
authors.forename: N
authors.initials: N
authors.lastname: Okada
authors.forename: S
authors.initials: S
authors.lastname: Nakagawa
mesh_terms: D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects*; D006801:Humans; D007202:Indicators and Reagents; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D018613:Microscopy, Confocal; D053758:Nanoparticles; D010316:Particle Size; D017382:Reactive Oxygen Species / Q000378:metabolism; D012822:Silicon Dioxide / Q000494:pharmacology*; D013499:Surface Properties
chemical_list: D007202:Indicators and Reagents; D017382:Reactive Oxygen Species; D012822:Silicon Dioxide; D020169:Caspases