U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Bryant C. Nelson (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 78

Polyethyleneimine/polyethylene glycol-conjugated gold nanoparticles as nanoscale positive/negative controls in nanotoxicology: Testing in frog embryo teratogenesis assay-Xenopus and mammalian tissue culture system

March 15, 2023
Author(s)
Vytas Reipa, Alessandro Tona, Feng Yi, Bryant C. Nelson, David A. LaVan, Vincent A. Hackley, Tae Joon Cho
Despite the great potential of using positively charged gold nanoparticles (AuNPs) in nanomedicine, no systematic studies have been reported on their synthesis optimization or colloidal stability under physiological conditions until a group at the National

Inhibition of human APE1 and MTH1 DNA repair proteins by dextran-coated g-Fe2O3 ultrasmall superparamagnetic iron oxide nanoparticles

February 28, 2023
Author(s)
Erdem Coskun, Pawel Jaruga, Miral M. Dizdar, Bryant C. Nelson, Neenu Singh, Leona Scanlan, Shareen Doak
Aim: To quantitatively evaluate the inhibition of human DNA repair proteins APE1 and MTH1 by dextran-coated γ-Fe2O3 ultrasmall superparamagnetic iron oxide nanoparticles (dUSPIONs). Materials & methods: Liquid chromatography–tandem mass spectrometry with

Orthogonal and complementary measurements of properties of drug products containing nanomaterials

January 6, 2023
Author(s)
Bryant C. Nelson, Elijah Petersen, Carl Simon Jr., Sven-Even Borgos, Luigi Calzolai, Jeremie Parot, Matthias Roesslein, Fanny Caputo, Xiaoming Xu
Quality control of pharmaceutical and biopharmaceutical products, and verification of their safety and efficacy, depends on reliable measurements of critical quality attributes (CQAs). The task becomes particularly challenging for drug products and

Current Nanomaterials Toxicity Testing Needs and Use of New Approach Methodologies Among Selected U.S. Federal Agencies

April 11, 2022
Author(s)
Elijah Petersen, Patricia Ceger, Jayme Coyle, David Allen, Raymond Derk, Natalia Garcia-Reyero, John Gordon, Nicole Kleinstreuer, Joanna Matheson, Danielle McShan, Bryant C. Nelson, Anil Patri, Liying Rojanasakul, Abhilash Sasidharan, Louis Scarano, Xiaoqing Chan
Engineered nanomaterials (ENMs) come in a wide array of shapes, sizes, surface coatings, and compositions, and often possess novel or enhanced properties compared to larger sized particles of the same elemental composition. To ensure the safe

Preparation, Characterization, and Biological Activity of Stability-Enhanced Polyethyleneimine-Conjugated Gold Nanoparticles (Au-PEI@NIST) for Biological Application

September 16, 2021
Author(s)
Tae Joon Cho, Vincent A. Hackley, Feng Yi, David A. LaVan, Vytas Reipa, Alessandro Tona, Bryant C. Nelson, Christopher Sims, Natalia Farkas
In this special publication, we report on a modified synthetic process that results in a stable suspension of Au-PEI nanoparticles, Au-PEI@NIST. Synthesized materials were characterized using an orthogonal approach that included dynamic light scattering

Combining secondary ion mass spectrometry image depth profiling and single particle inductively coupled plasma mass spectrometry to investigate the uptake and biodistribution of gold nanoparticles in Caenorhabditis elegans

May 20, 2021
Author(s)
Monique Johnson, Joe Bennett, Antonio Montoro Bustos, Shannon Hanna, Andrei Kolmakov, Nicholas Sharp, Elijah Petersen, Christopher Sims, Bryant C. Nelson, Patricia Lapasset
Analytical techniques capable of determining the spatial distribution and quantity (mass and/or particle number) of engineered nanomaterials in organisms are essential for characterizing nano-bio interactions and for nanomaterial risk assessments. Here, we

Measurement and Standardization Challenges for Exosome-Based Delivery Vectors

September 4, 2020
Author(s)
Bryant C. Nelson, Lili Wang, Samantha D. Maragh, Paul C. DeRose, Elzafir B. Elsheikh, Wyatt N. Vreeland, Ionita Ghiran, Jennifer Jones
Extracellular vesicles (EVs), and in particular exosomes, have the potential to revolutionize the development and efficient delivery of clinical therapeutics. In this Perspective, we focus on providing a brief introduction to the landscape of exosome-based

Emerging Standards for Nanotechnology-Enabled Medical Products

February 21, 2020
Author(s)
Bryant C. Nelson, Caterina Minelli, Shareen H. Doak, Matthias Roesslein
The development and application of nanotechnology-enabled medicinal products, including drugs, devices and in vitro diagnostics, is rapidly expanding in the global market place. In this review, the focus is on providing the reader an introduction to the

Implications of DNA Damage and DNA Repair on Human Diseases

January 10, 2020
Author(s)
Bryant C. Nelson, M Miral Dizdar
Cellular DNA damage is implicated in the etiology and progression of many different types of human disorders and diseases. Much of the current research in the DNA damage field is devoted towards understanding the mechanisms and biological implications of

Measurement of Oxidatively Induced DNA Damage in Caenorhabditis elegans with High-Salt DNA Extraction and Isotope-Dilution Mass Spectrometry

August 27, 2019
Author(s)
Leona D. Scanlan, Pawel Jaruga, Sanem Hosbas Coskun, Christopher Sims, Shannon Hanna, Jamie L. Almeida, David N. Catoe, Bryant C. Nelson, Miral M. Dizdar, Erdem Coskun
Caenorhabditis elegans (C. elegans) is used as a medical and systems toxicity model organism for environmental and developmental assays that include high-throughput methods and genetic studies. However, little is known about background levels of

Approaches for the Quantitative Analysis of Oxidation State in Cerium Oxide Nanomaterials

September 21, 2018
Author(s)
Christopher M. Sims, Russell A. Maier, Aaron C. Johnston-Peck, Justin M. Gorham, Vincent A. Hackley, Bryant C. Nelson
Cerium oxide nanomaterials (nanoceria, CNMs) are receiving increased attention from the research community due to their unique chemical properties, most prominent of which is their ability to alternate between the Ce3+ and Ce4+ oxidation states. While many

Agglomeration of Escherichia coli with positively charged nanoparticles can lead to artifacts in a standard Caenorhabditis elegans toxicity assay

April 19, 2018
Author(s)
Shannon Hanna, Antonio Montoro Bustos, Alexander W. Peterson, Vytas Reipa, Leona D. Scanlan, Sanem Hosbas Coskun, Tae Joon Cho, Monique Johnson, Vincent A. Hackley, Bryant C. Nelson, Michael R. Winchester, John T. Elliott, Elijah Petersen
The increased use and incorporation of engineered nanoparticles (ENPs) in consumer products requires a robust assessment of their potential environmental implications. However, a lack of standardized methods for nanotoxicity testing has yielded results

Counting Caenorhabditis elegans: Protocol Optimization and Applications for Population Growth and Toxicity Studies in Liquid Medium

January 17, 2018
Author(s)
Steven Lund, Sanem Hosbas Coskun, Monique Johnson, Christopher Sims, Elijah Petersen, John T. Elliott, Bryant C. Nelson, Leona D. Scanlan, Shannon K. Hanna, Karina Brignoni, Patricia Lapasett
The nematode Caenorhabditis elegans is used extensively in molecular, toxicological and genetics research. However, standardized methods for counting nematodes in liquid culture do not exist despite the wide use of nematodes and need for accurate

Controlled Potential Electrooxidation of Genomic DNA

January 11, 2018
Author(s)
Vytautas Reipa, Donald H. Atha, Sanem Hosbas Coskun, Christopher M. Sims, Bryant C. Nelson
Exposure of mammalian cells to oxidative stress can result in DNA damage that adversely affects many cell processes. We used bulk electrolysis in an electrochemical system and gas chromatographic mass spectrometric analysis (GC/MS/MS) to control and

Sucrose density gradient centrifugation for efficient separation of engineered nanoparticles from a model organism, Caenorhabditis elegans

October 11, 2017
Author(s)
Monique E. Johnson, Antonio R. Montoro Bustos, Elijah J. Petersen, Shannon K. Hanna, Karen E. Murphy, Lee L. Yu, Bryant C. Nelson, Michael R. Winchester
This protocol describes a strategy for separating Caenorhabditis elegans (C. elegans) from engineered nanomaterials, a critical step for accurate quantification in uptake studies. Conventional rinsing procedures, typically comprised of water or buffer

Redox-active Nanomaterials for Nanomedicine Applications

October 6, 2017
Author(s)
Christopher Sims, Shannon Hanna, Daniel A. Heller, Christopher Horoszko, Monique Johnson, Antonio Montoro Bustos, Vytas Reipa, Kathryn Riley, Bryant C. Nelson
Nanomedicine utilizes the remarkable properties of nanomaterials for the diagnosis, treatment, and prevention of disease. Many of these nanomaterials have been shown to have robust antioxidative properties, potentially functioning as strong scavengers of

Multiple method analysis of TiO2 nanoparticles uptake, accumulation and effects in rice (Oryza sativa L.) plants

August 4, 2017
Author(s)
Yinqging Deng, Elijah Petersen, Katie Challis, Savelas A. Rabb, Richard D. Holbrook, James Ranville, Bryant C. Nelson, Baoshan Xing
Understanding the translocation of nanoparticles (NPs) into plants is challenging because quantitative and qualitative methods are still being developed and the comparability of results among different methods is unclear. In this study, the uptake of NPs

Exposure to Engineered Nanomaterials: Impact on DNA Repair Pathways

July 13, 2017
Author(s)
Neenu Singh, Bryant C. Nelson, Leona D. Scanlan, Erdem Coskun, Pawel Jaruga, Shareen Doak
Some engineered nanomaterials (ENMs) may have the potential to cause damage to the genetic material in living systems. The mechanistic machinery functioning at the cellular/molecular level, in the form of DNA repair processes, has evolved to help

Quantitative Analysis of Oxidation State in Cerium Oxide Nanomaterials

May 14, 2017
Author(s)
Christopher Sims, Russell Maier, Aaron Johnston-Peck, Justin Gorham, Vincent A. Hackley, Bryant C. Nelson
Cerium oxide nanoparticles (nanoceria) are receiving increased attention from the research community due to the large number and wide range of their current and potential applications. The attractiveness of nanoceria for these various applications is

Biophysical Characterization of Functionalized Titania Nanoparticles and Their Application in Dental Adhesives

February 2, 2017
Author(s)
Jirun Sun, Elijah J. Petersen, Stephanie S. Watson, Christopher M. Sims, Alexander Kassman, Stanislav A. Frukhtbeyn, Drago Skrtic, Meryem T. Ok, Deborah S. Jacobs, Qiang Ye, Bryant C. Nelson
It is demonstrated that carboxylic acid-functionalized titanium dioxide (TiO2) NPs produce significantly higher levels of reactive oxygen species (ROS) after visible light irradiation (400–800 nm, 1600 mW/cm2) in comparison to nonfunctionalized TiO2 NPs

Separation, Sizing, and Quantitation of Engineered Nanoparticles in an Organism Model Using Inductively Coupled Plasma Mass Spectrometry and Image Analysis

December 16, 2016
Author(s)
Monique E. Johnson, Shannon Hanna, Antonio R. Montoro Bustos, Christopher M. Sims, Lindsay C. Elliott, Babak Nikoobakht, John T. Elliott, Richard D. Holbrook, Keana C. Scott, Karen E. Murphy, Elijah J. Petersen, Lee L. Yu, Bryant C. Nelson, Akshay Lingayat, Adrian C. Johnston
For environmental studies assessing uptake of orally ingested engineered nanoparticles (ENPs), a key step in ensuring accurate quantification of ingested ENPs is efficient separation of the organism from ENPs that are either nonspecifically adsorbed to the

Defense Mechanisms and Nutrient Displacement in Arabidopsis thaliana upon Exposure to CeO2 and In2O3 Nanoparticles

September 1, 2016
Author(s)
Bryant C. Nelson, Sanem Hosbas Coskun, Chuanxin Ma, Hong Li, Huiyuan Guo, Craig Musante, Jason C. White, Baoshan Xing, Om P. Dhankher
Metal-based nanoparticles (NPs) can cause toxicity to terrestrial plants, however there is little understanding of plant defense mechanisms that may counteract nanotoxicity. In the present study, we investigated the defense mechanisms of Arabidopsis

Emerging Metrology for High Throughput Nanomaterial Genotoxicology

August 26, 2016
Author(s)
Bryant C. Nelson, Christa W. Wright, Yuko Ibuki, Maria Moreno-Villanueva, Hanna L. Karlsson, Giel Hendriks, Christopher M. Sims, Neenu Singh, Shareen H. Doak
The rapid development of the engineered nanomaterial (ENM) manufacturing industry has accelerated the incorporation of ENMs into a wide variety of consumer products across the globe. Unintentionally or not, some of these ENMs may be introduced into the

Design, sensitivity analysis, and testing of a Caenorhabditis elegans nanoecotoxicity assay

August 11, 2016
Author(s)
Shannon Hanna, Gregory A. Cooksey, Bryant C. Nelson, John T. Elliott, Elijah J. Petersen
Increasing production and usage of engineered nanomaterials (ENMs) has generated widespread interest in measuring their environmental and human health effects. However, the lack of standardized methods for these measurements has often led to contradictory