IN-VIVO EXPOSURE CHARACTERIZATION AND VISUALIZATION OF SWNH AGGREGATES
- ORNL
As the manufacturing and use of nanomaterials and nanoparticle clusters/aggregates become prevalent in the future, it will be necessary to understand the biological interactions with this new class of materials introduced through various routes, intentionally or unintentionally. However, there currently exist a host of technical/methodological issues related to nanotoxicological study. For example, the ability to generate reproducible precision nanomaterial and nanoparticles is critically needed for both toxicological evaluation and pharmaceutical applications. Technology for tracing and visualization of nanomaterials in biological systems are also lacking. Single-walled carbon nanohorn (SWNH) is a unique carbon nanostructure belonging to the same family as the famous carbon nanotubes. SWNH aggregates can be produced through laser vaporization of carbon at room temperature; the aggregates are of particular interest to energy application such as hydrogen storage and new-generation of fuel cells. Unlike carbon nanotubes that are made using metal catalysts, SWNHs can be made without the use of a metal catalyst providing an opportunity for nanotoxicological study of purest carbon nanoparticles with no complication of trace metal toxicity that the nanotubes might have. We summarize results from our ongoing biological research on SWNHs. Our results were from in vivo animal aspiration experiments, in contrast to the results of a recent publication that were based on phenotypic observation of cell-line exposure experiments. The characterization results of ORNL-produced SWNHs are presented in Figure 1, which include low- (Figure 1a) and high-resolution (Figure 1b) structural images of SWNHs, the thermal gravimetric analysis (Figure 1c) and characteristic Raman (Figure 1d) results. We coated the SWNH powder with Pluronic F-127, which is a biocompatible polymer, to facilitate the dispersion of SWNHs in suspension during pressure-driven nebulization in mice aspiration and nose-only inhalation experiments. The phenotypic and genomic expression results are reported by. Twenty-two inflammatory measures from bronchoalveolar lavage were assayed. Only five showed significant changes from the control (e.g., G-CSF, GM-CSF, IP-10, and IL-5) in 24 hours after exposure indicating acute inflammatory responses; however, the responses subsided in 7 days and no significant difference could be found between the control and exposed groups. Whole lung microarray analysis also found few differences between SWNH-exposed and controls of several genes in 24 hours. The SWNH aggregates did penetrate cell membranes; the stained optical microscopy images show the presence of SWNH aggregates in mice red blood cell. The images results are consistent with visualization by using the Scanning Near Field Ultrasound Holography (SNFUH) available at the Oak Ridge National Laboratory. The SNFUH also provided transport information regarding the transport dynamics of the SWNH aggregates into the cells. The visualization showing consistent results with those obtained from the stained optical microscopy.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS); Mouse Genetics Research Facility
- Sponsoring Organization:
- USDOE Laboratory Directed Research and Development (LDRD) Program
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 932620
- Resource Relation:
- Conference: The 3rd International Symposium on Nanotechnology, Occupational and Environmental Health, Taipei, Taiwan, Taiwan, 20070829, 20070901
- Country of Publication:
- United States
- Language:
- English
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