Amorphous nanosilica induce endocytosis-dependent ROS generation and DNA damage in human keratinocytes

• Published in: Particle and fibre toxicology Vol. 8; no. 1; p. 1
• Main Authors: Nabeshi, Hiromi, Yoshikawa, Tomoaki, Matsuyama, Keigo, Nakazato, Yasutaro, Tochigi, Saeko, Kondoh, Sayuri, Hirai, Toshiro, Akase, Takanori, Nagano, Kazuya, Abe, Yasuhiro, Yoshioka, Yasuo, Kamada, Haruhiko, Itoh, Norio, Tsunoda, Shin-ichi, Tsutsumi, Yasuo
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 15.01.2011; BioMed Central; BMC
• Subjects: Amorphous substances; Atoms & subatomic particles; Biological effects; Cell Line; Comet Assay; Cosmetics; Deoxyribonucleic acid; DNA; DNA - drug effects; DNA Damage; Drug Therapy, Combination; Endocytosis - drug effects; Endocytosis - physiology; Genetic aspects; Health sciences; Humans; Keratinocytes; Keratinocytes - drug effects; Medical research; Nanomaterials; Nanoparticles; Nanoparticles - toxicity; Nanotechnology; Nucleic Acid Synthesis Inhibitors - pharmacology; Particle Size; Physicochemical properties; Physiological aspects; Quantum dots; Reactive oxygen species; Reactive Oxygen Species - metabolism; Silica; Silicon Dioxide - toxicity; Skin; Studies; Japan
• ISSN: 1743-8977; 1743-8977
• DOI: 10.1186/1743-8977-8-1

Clarifying the physicochemical properties of nanomaterials is crucial for hazard assessment and the safe application of these substances. With this in mind, we analyzed the relationship between particle size and the in vitro effect of amorphous nanosilica (nSP). Specifically, we evaluated the relationship between particle size of nSP and the in vitro biological effects using human keratinocyte cells (HaCaT). Our results indicate that exposure to nSP of 70 nm diameter (nSP70) induced an elevated level of reactive oxygen species (ROS), leading to DNA damage. A markedly reduced response was observed using submicron-sized silica particles of 300 and 1000 nm diameter. In addition, cytochalasin D-treatment reduced nSP70-mediated ROS generation and DNA damage, suggesting that endocytosis is involved in nSP70-mediated cellular effects. Thus, particle size affects amorphous silica-induced ROS generation and DNA damage of HaCaT cells. We believe clarification of the endocytosis pathway of nSP will provide useful information for hazard assessment as well as the design of safer forms of nSPs.