Amorphous silica coating potentially protects against iron homeostasis disruption induced by nano-iron oxide in acute and sub-chronic in vitro exposure models

Details

• Personal Author:
  Davidson D ; Demokritou P ; Derk R ; Kornberg T ; Stueckle, Todd A. ; Wang L
• Description:
  Nano-scaled iron oxide (nFe2O3) has unique physicochemical properties which allow for its use in a wide range of applications, including advanced drug delivery systems and environmental catalysts. However, the existing literature is conflicting as to this particle's ability to induce adverse effects via inhalation - a particular concern for those exposed in an occupational setting. Our previous work showed that a continuous delivered dose (0.18 microg/cm2) of nFe2O3 induced a neoplastic-like transformation in human primary small airway epithelial cells after 10 weeks exposure, with evidence suggesting that this transformation is related to disruption of iron homeostasis in the exposed cells. Herein, we utilized a sub-chronic exposure model to investigate the potentially protective qualities of an amorphous nano-silica (nSiO2) coating on nFe2O3-induced bio-effects using a human lung bronchial epithelial cell line. Starting at 2.5 months of continuous exposure (administered dose of 0.6 microg/cm2), nFe2O3 treated cells displayed significantly elevated mitochondrial activity and reactive oxygen species (ROS) generation, as compared to non-treated controls, and this activity became dramatically heightened starting at 4 months of exposure. Cells sub-chronically exposed to nSiO2-nFe2O3, however, showed no significant mitochondrial activity or ROS generation increase compared to non-treated cells. Furthermore, starting at 3 months continuous exposure, nFe2O3 exposed cells possessed elevated intracellular iron levels compared to both nSiO2-nFe2O3 treated and non-treated cells, indicating that nSiO2-coating has the potential to reduce or prevent particle solubilization, thus reducing iron homeostasis overload and subsequent adverse outcomes. Overall, our data suggests that nSiO2 coating has the potential to protect against nFe2O3-induced iron homeostasis disruption and subsequent cellular transformation, supporting a strategy for safe-by-design nanoparticle manufacturing. [Description provided by NIOSH]
• Subjects:
  Cells, Cultured Environmental Exposure Laboratories Lung Occupational Exposure Occupational Health Respiratory System Safety Toxicology
• Keywords:
  Acute Exposure Amorphous Silica Biological Effects Cell Cultures Cell Transformation Cellular Effects Cellular Reactions Coatings Dose Response Exposure Assessment Exposure Levels Humans In Vitro Study Iron Compounds Iron Oxides Laboratory Testing Lung Cells Nanomaterials Nanoparticles Nanoscale Nanotechnology Nanotoxicology Neoplastic Agents Neoplastic Transformation Protective Coatings Reactive Oxygen Species ROS

  More +
• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Maryland ; Massachusetts ; OSHA Region 1 ; OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  156
• Issue:
  1
• NIOSHTIC Number:
  nn:20049398
• Citation:
  Toxicologist 2017 Mar; 156(1):123
• CAS Registry Number:
  Iron oxide (Fe2O3) (CAS RN 1309-37-1) ; Silica (CAS RN 7631-86-9)
• Federal Fiscal Year:
  2017
• NORA Priority Area:
  Manufacturing
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 56th Annual Meeting and ToxExpo, March 12-16, 2017, Baltimore, Maryland
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:89138fc025dbb09e384d7ba185c2139b572eb748ac423cc39739a11a5426f2708ab2794c3b929e7bf91f72bf4c13a252f35c0ed12937ead070a806ad83864c29
• Download URL:
  https://stacks.cdc.gov/view/cdc/203852/cdc_203852_DS1.pdf
• File Type:
  [PDF - 950.73 KB ]