Sigma Xi Student Research Showcase Presentation


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Sigma Xi Student Research Showcase Presentation

  1. 1. Effect of the Nano-Bio Interface on theGenotoxicity of Titanium Dioxide Nanoparticles and Associated Cellular Response Raju Y. Prasad Ph.D Candidate Environmental Science and Engineering Department UNC Gillings’ Global School of Public Health GPSF University Research Day February 26, 2012 1
  2. 2. Brief History of Engineered Nanoparticles“There’s Plenty of Room at the Bottom” – Richard Feynman, Nobel Laureate Physicist, 19591985 – First nanoparticle 2001 – President Clinton Development of synthesized (carbon establishes National Nanoparticles for: fullerenes) Nanotechnology Initiative • Drug Delivery • Consumer Products • Industrial Products “The 2013 Federal Budget provides $1.8 billion for the National Nanotechnology Initiative (NNI)” 2
  3. 3. Definition of Engineered Nanoparticles ~1.6 m ~2 nm width 100 10-1 10-2 10-3 10-6 10-9 1-100 nm meter decimeter centimeter millimeter micrometer nanometerParticles with a size dimension between 1 and 100 nmthat show novel properties that are not found in bulk samples of the same material 3
  4. 4. Titanium Dioxide NanoparticlesCrystal Structures: Anatase, Rutile and Brookite High Refractive Index, White Pigmentation 4
  5. 5. Use of Titanium Dioxide Nanoparticles in Consumer Products Sunscreens : ~10-100 µg Ti/mg product (1-10%) Weir et al. Environ Sci Technol 2012 5
  6. 6. Association of Physicochemical Properties with ToxicityDue to small size dimensions, large surface area to volume ratio, novel properties, and potential exposure, it is important to determine effects on human health Sayes et al. Tox Sci 2006 There is a need to determine physicochemical characteristics of nanoparticles that can lead to adverse effects 6
  7. 7. Nano-Bio InterfaceFormation of Protein Corona Interaction with Cells Nel et al. Nature Materials 2009 7
  8. 8. Impact of Nano-Bio Interface on Genotoxicity Degussa P25 TiO2 nanoparticlesCell Culture Medium:Serum-free KGM KB DM KF • Cell Culture medium • PBS + 0.6% BSA + 0.01% • Cell Culture medium (KGM) + 0.1% BSA DSPC (surfactant) (KGM) + 10% FBS • 2 min probe sonication • 20 min cup sonication of • 2 min probe sonication of stock solution stock solution of stock solution • Centrifuged and re- suspended in cell culture medium (KGM) Effects on Human Lung Epithelial Cells (BEAS-2B)Prasad et al., 2013 ACS Nano 8
  9. 9. Agglomeration: Physicochemical Characteristic Impacted by the Nano-Bio Interface
  10. 10. Study HypothesisThe treatment medium that elicits the smallest nanoparticle agglomerates will be associated with cellular interaction and genotoxicity
  11. 11. Identification of the Protein Adsorbed to the Surface of the Nanoparticles KB DM KF 2 Ti O i n K 2 2 B Ti O i n D Ti O i n K M F ladder kDa 250 130 95 72 55 36 28Tedja et al., 2012 ACS Nano, Lundqvist et al., 2008 PNAS 11
  12. 12. Size Measurements in Treatment Media0h KB24 h DM KFPrasad et al., 2013 ACS Nano 12
  13. 13. No Significant Cytotoxicity in BEAS-2B cells 0 µg/ml 10 µg/ml 20 µg/ml 50 µg/ml 100 µg/ml MMS (100 µM) Li ve: C cei n- al AM D ead: Pr opi di um I odi dePrasad et al., 2013 ACS Nano 13
  14. 14. Highest Cellular Uptake in KF Medium Determined by Flow Cytometry Flow Cytometry HistogramsPrasad et al., 2013 ACS Nano 14
  15. 15. Evaluation of Genotoxicity (Damage to the Genome) DNA Damage Chromosomal Damage Binucleated cell (BN) treat 24 h 48 h Add CytoSpin cells cytochalasin B on glass slides Micronucleated Binucleated cell (MN)Fenech et al. Mutat Res-Fund Mol M 2000 , Kirsch-Volders et al. Mutat Res-Fund Mol M 2003, Singh et al. Mutat Res 1991 15
  16. 16. TiO2 Nanoparticles Induce DNA Damage C r ol ont D aged amPrasad et al., 2013 ACS Nano 16
  17. 17. Micronuclei Induction Only in KF MediumPrasad et al., 2013 ACS Nano 17
  18. 18. Increased % of S-Phase Cells in KF Medium Cell CyclePrasad et al., 2013 ACS Nano 18
  19. 19. Summary Medium that elicited smallest agglomerates (KF) was associated with highest cellular uptake, micronuclei formation, and increased % of cells in S phase. In contrast, DNA damage was induced regardless of agglomeration and cellular uptake Inhalation exposure to titanium dioxide nanoparticles may not induce micronuclei in lung cells, whereas, serum proteins in “blood” (for example, ingestion exposure) may act to lower agglomeration and inducePrasad et al., 2013 ACS Nano micronuclei formation. 19
  20. 20. Thank youDr. Rebecca Fry Dr. David DeMarini Dr. Ivan Rusyn Dr. Jim Swenberg Dr. Bill Kaufmann Kathleen Wallace Dr. Carl Blackman Dr. Nana Nikolaishvili-Feinberg Kaitlin Daniel Dr. Jorge Muniz Ortiz Dr. Stephanie Cohen Alan Tennant Dr. Andrew Kligerman Mark Olorvida Jim Campbell Dr. Robert Zucker Bentley Midkiff Micaela Killius Dr. Steve Simmons Mervi Eeva Sharon Leavitt Dr. Kevin Dreher Dr. Stephanie Smith-Roe Ben Castellon Dr. Bellina Veronesi Lisa Smeester Jenna Strickland Dr. Brian Chorley Dr. Kathryn Bailey Danielle Ackerman Dr. Thomas Knudsen Dr. Bhavesh Ahir Peggy Matthews Dr. Kirk Kitchin Dr. Julia Rager Sarah Warren Dr. Will Boyes Alison Sanders Nancy Hanley Dr. Bill Lefew Fry lab Laura Degn Keith Tarpley Kristen Sanders U.S. EPA NHEERL Questions?