Judges’ Queries and Presenter’s Replies

  • Icon for: Qiaobing Xu

    Qiaobing Xu

    Judge
    May 20, 2013 | 09:49 p.m.

    Excellent work, WV team. how did you differentiate the subsacrolemmal mitochondria and interfibriallar one in terms of energy production?(figure 5)
    In terms of gene mapping, what do you expect, e.g. in case of particle induced heart injury, what gene will be up-regulated or down-regulated?

  • Icon for: Cody Nichols

    Cody Nichols

    Presenter
    May 22, 2013 | 05:20 p.m.

    We differentiated the subsarcolemmal and interfibrillar mitochondria by isolating them from the tissue using differential centrifugation (different speeds and duration isolate different fractions). For the interfibrillar mitochondria, we have to break the myofibrils using a protein. Once the two subpopulations of mitochondria are separated, we are able to measure the change in oxygen concentration, which reflects energy production, after the mitochondria have been fueled with glutamate, malate and ADP.
    In terms of gene mapping, our initial investigations associated with proteomic data from heart tissue suggest that genes involved in cardiac fibrosis and enlargement may be affected by nanomaterial exposure.

  • May 21, 2013 | 09:49 a.m.

    I have two rather unrelated questions. First, is there an advantage to using IGD over SAM? How much more expensive/high throughput is one over the other?

    Do you have any preliminary ideas on what genetic pathways are associated with the cardiac function results you have to date?

  • Icon for: Cody Nichols

    Cody Nichols

    Presenter
    May 22, 2013 | 05:22 p.m.

    Inert Gas Condensation (IGC) and Surfactant-Assisted Milling (SAM) each have advantages and disadvantages. IGC produces very uniform nanoparticles and gives us exceptional control over their growth; however, it requires ultra-high vacuum (making it more expensive and time consuming than SAM) and produces tens of milligrams of material per hour.
    SAM is inexpensive and commonly used in industrial processes. We can produce gram-size quantities in the lab and industrial mills can produce kilogram and larger batches; however, milling produces a broad range of particle sizes. We thus have to use an additional centrifugation step to narrow the size distribution.
    The computer algorithms that identify genetic pathways were developed and validated using data from the lung; however, initial pathway analysis on heart tissue indicates that the genetic pathways affected are involved in free radical scavenging, lipid metabolism, molecular transport and nucleic acid metabolism.

  • May 21, 2013 | 06:16 p.m.

    Very interesting work. I guess that effect of nanomaterial may be dependent of its size. What was the diameter of gold nanoparticles used in this study? Did you have a chance to examine effects of particle size in a systematic manner?

  • Icon for: Cody Nichols

    Cody Nichols

    Presenter
    May 22, 2013 | 05:23 p.m.

    We used gold as an example in the video; however, the cardiac study used commercially available titanium dioxide nanoparticles, which have a mean aerodynamic diameter of 159 nm and a wide size distribution. Despite lack of control over the properties of commercially produced nanomaterials, a wide range of consumer products already use these materials, and we feel it is important to understand them.
    Particle size is known to have important effects on biological function. One aspect of our approach is developing nanomaterials with very specific sizes, shapes and chemical functionalities so that we can understand the correlation between chemical and physical properties and biological impacts.

  • May 21, 2013 | 07:22 p.m.

    This is very general presentation about the methods and approaches. Can you, please, provide some details, more about your work and results. What kind of nano particles do you study? Gold, iron, or something else? Any dependence of the effects on material, size, shape?

  • Icon for: Cody Nichols

    Cody Nichols

    Presenter
    May 22, 2013 | 05:41 p.m.

    Our investigations to date have involved titanium dioxide and carbon nanotubes due to the wide array of potential applications and presence in commercially available products. A strength of our approach is that our methods are not nanoparticle specific, but can be applied to virtually any nanomaterial. We expect significant differences in biological response as a function of material, shape and size. One focus of our research is designing nanoparticles with very well controlled sizes and shapes so that we can investigate the specific dependence of the biological response on physical and chemical properties. We are currently focusing on fabricating iron and iron-based nanoparticles due to their medical applications.

  • Icon for: Qi-Huo Wei

    Qi-Huo Wei

    Judge
    May 21, 2013 | 09:14 p.m.

    Thanks for making the presentation general so that I can understand it easily. Can you give details about what you plan to do, such as what nano-materials to use, what genes to be tested, and how to relate the cellular mechanisms to the whole system(body) exposure experiments?

  • Icon for: Cody Nichols

    Cody Nichols

    Presenter
    May 22, 2013 | 05:41 p.m.

    We are particularly interested in two classes of nanomaterials: those that are already being used in consumer products (carbon nanotubes, silver, titanium dioxide) and model nanoparticles that will allow us to investigate the relationship between biological response and specific physical and chemical properties. Coupling our computer algorithms with micro-array data allows us to efficiently test and analyze any set of genes, but we are most interested in genes involved in cardiac fibrosis and enlargement. Whole-body exposure will be related to cellular mechanisms by analyzing blood and tissues for the expression of cytokines associated with inflammation or the presence of the nanoparticle.

  • Further posting is closed as the competition has ended.

Presentation Discussion

  • Icon for: Terri La Count

    Terri La Count

    Trainee
    May 23, 2013 | 09:21 a.m.

    Enjoyed your video! I like that you are approaching the problem from different perspectives, culminating in very interesting work. As a WVU alumna, I am proud to see great work occurring at WVU! As a skin scientist, I find nanoparticle research necessary.

  • Icon for: Kelly Pisane

    Kelly Pisane

    Co-Presenter
    May 23, 2013 | 01:45 p.m.

    Thank you so much! We really enjoyed working on this.

  • Further posting is closed as the competition has ended.

  1. Cody Nichols
  2. http://www.igert.org/profiles/5245
  3. Graduate Student
  4. Presenter’s IGERT
  5. West Virginia University
  1. Julian Dymacek
  2. http://www.igert.org/profiles/5277
  3. Graduate Student
  4. Presenter’s IGERT
  5. West Virginia University
  1. Kelly Pisane
  2. http://www.igert.org/profiles/5267
  3. Graduate Student
  4. Presenter’s IGERT
  5. West Virginia University
  1. Nicole Shamitko-Klingensmith
  2. http://www.igert.org/profiles/5268
  3. Graduate Student
  4. Presenter’s IGERT
  5. West Virginia University

Does size matter? Connecting materials and biological researchers to understand how nanomaterials interact with life.

Shrinking materials can change more than their sizes. Nanomaterials can exhibit different properties compared to their larger counterparts. These unique properties have made nanoparticles popular in many consumer products including makeup, sunscreen, and even food. Materials that are harmless in their larger forms can interact very differently with biological systems when they become small. If we are to take advantage of the unique properties of nanoparticles in consumer products, we must first determine the effects of nanoparticles on people and the environment. One reason nanoparticles interact differently with biological systems is that they can infiltrate places larger particles cannot. Additionally, their physical and chemical properties—the properties that make them useful—can be very different from those of larger particles. We unite nanomaterial and toxicology experts to determine the mechanisms by which nanoparticles interact with biological systems with the goal of producing better, safer nanoparticles. Understanding the toxicological impacts of nanoparticles on biological systems requires investigation from the genetic to the organismal level. Changes in the genetic information are analyzed using new computer algorithms to identify which biological pathways are affected by nanoparticle exposure. At the subcellular level, we have demonstrated that nanoparticle pulmonary exposure disrupts cardiac mitochondrial function. Understanding the driving mechanism behind this disruption will allow us better protection against cellular damage. Traditional physical techniques such as atomic force microscopy are applied to understand nanoscale cellular deformations and subsequent changes in function. Combining toxicological information at different scales will allow us to develop safer nanoparticles for consumer products.