Fluorescently Labeled Cellulose Nanofibers for Environmental Health and Safety Studies
Ilabahen Patel,
Jeremiah Woodcock,
Ryan Beams,
Stephan J. Stranick,
Ryan Nieuwendaal,
Jeffrey W. Gilman,
Marina R. Mulenos,
Christie M. Sayes,
Maryam Salari,
Glen DeLoid,
Philip Demokritou,
Bryan Harper,
Stacey Harper,
Kimberly J. Ong,
Jo Anne Shatkin,
Douglas M. Fox
Affiliations
Ilabahen Patel
Department of Chemistry, American University, Washington, DC 20016, USA
Jeremiah Woodcock
Materials Science and Engineering Division, Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
Ryan Beams
Materials Science and Engineering Division, Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
Stephan J. Stranick
Materials Science and Engineering Division, Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
Ryan Nieuwendaal
Materials Science and Engineering Division, Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
Jeffrey W. Gilman
Materials Science and Engineering Division, Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
Marina R. Mulenos
Department of Environmental Science, Baylor University, Waco, TX 76798, USA
Christie M. Sayes
Department of Environmental Science, Baylor University, Waco, TX 76798, USA
Maryam Salari
Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, T.H. Chan School of Public Health, Harvard University, Boston, MA 02115, USA
Glen DeLoid
Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, T.H. Chan School of Public Health, Harvard University, Boston, MA 02115, USA
Philip Demokritou
Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, T.H. Chan School of Public Health, Harvard University, Boston, MA 02115, USA
Bryan Harper
Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA
Stacey Harper
Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA
Kimberly J. Ong
Vireo Advisors, LLC, Boston, MA 02130, USA
Jo Anne Shatkin
Vireo Advisors, LLC, Boston, MA 02130, USA
Douglas M. Fox
Department of Chemistry, American University, Washington, DC 20016, USA
An optimal methodology for locating and tracking cellulose nanofibers (CNFs) in vitro and in vivo is crucial to evaluate the environmental health and safety properties of these nanomaterials. Here, we report the use of a new boron-dipyrromethene (BODIPY) reactive fluorescent probe, meso-DichlorotriazineEthyl BODIPY (mDTEB), tailor-made for labeling CNFs used in simulated or in vivo ingestion exposure studies. Time-correlated single photon counting (TCSPC) fluorescence lifetime imaging microscopy (FLIM) was used to confirm covalent attachment and purity of mDTEB-labeled CNFs. The photoluminescence properties of mDTEB-labeled CNFs, characterized using fluorescence spectroscopy, include excellent stability over a wide pH range (pH2 to pH10) and high quantum yield, which provides detection at low (μM) concentrations. FLIM analysis also showed that lignin-like impurities present on the CNF reduce the fluorescence of the mDTEB-labeled CNF, via quenching. Therefore, the chemical composition and the methods of CNF production affect subsequent studies. An in vitro triculture, small intestinal, epithelial model was used to assess the toxicity of ingested mDTEB-labeled CNFs. Zebrafish (Danio rerio) were used to assess in vivo environmental toxicity studies. No cytotoxicity was observed for CNFs, or mDTEB-labeled CNFs, either in the triculture cells or in the zebrafish embryos.
