Tag Archives: Eric Vejerano

Of airborne nanomaterials, bacterial microbiomes, viral microbiomes, and paper sensors

There’s a Jan. 14, 2015 news item on Nanowerk from the Virginia Polytechnic Institute (Virginia Tech) which is largely a personal profile featuring some basic information (useful for those new to the topic) about airborne nanoparticles (Note: A link has been removed),

The Harvard educated undergraduate [Linsey Marr,  professor of civil and environmental engineering, Virginia Tech] who obtained her Ph.D. from University of California at Berkeley and trained as a postdoctoral researcher with a Nobel laureate of chemistry at MIT is now among a handful of researchers in the world who are addressing concerns about engineered nanomaterials in the atmosphere.

Marr is part of the National Science Foundation’s Center for the Environmental Implications of Nanotechnology and her research group has characterized airborne nanoparticles at every point of their life cycle. This cycle includes production at a commercial manufacturing facility, use by consumers in the home, and disposal via incineration.

A Jan. 14, 2015 Virginia Tech news release, which originated the news item, quotes Marr on the current thinking about airborne nanoparticles,

“Results have shown that engineered nanomaterials released into the air are often aggregated with other particulate matter, such as combustion soot or ingredients in consumer spray products, and that the size of such aggregates may range from smaller than 10 nanometers to larger than 10 microns,” Marr revealed. She was referring to studies completed by research group members Marina Quadros Vance of Florianopolis, Brazil, a research scientist with the Virginia Tech Institute of Critical Technology and Applied Science, and Eric Vejerano, of Ligao, Philippines, a post-doctoral associate in civil and environmental engineering.

Size matters if these aggregates are inhaled.

Another concern is the reaction of a nanomaterial such as a fullerene with ozone at environmentally relevant concentration levels. Marr’s graduate student, Andrea Tiwari, of Mankato, Minnesota, said the resulting changes in fullerene could lead to enhanced toxicity.

The story then segues into airborne pathogens and viruses eventually honing in on virus microbiomes and bacterial microbiomes (from the news release),

Marr is a former Ironman triathlete who obviously has strong interests in what she is breathing into her own body. So it would be natural for her to expand her study of engineered nanoparticles traveling in the atmosphere to focus on airborne pathogens.

She did so by starting to consider the influenza virus as an airborne pollutant. She applied the same concepts and tools used for studying environmental contaminants and ambient aerosols to the examination of the virus.

She looked at viruses as “essentially self-assembled nanoparticles that are capable of self-replication.”

Her research team became the first to measure influenza virus concentrations in ambient air in a children’s day care center and on airplanes. When they conducted their studies, the Virginia Tech researchers collected samples from a waiting room of a health care center, two toddlers’ rooms and one babies’ area of a childcare center, as well as three cross-country flights between Roanoke, Virginia., and San Francisco. They collected 16 samples between Dec. 10, 2009 and Apr. 22, 2010.

“Half of the samples were confirmed to contain aerosolized influenza A viruses,” Marr said. The childcare samples were the most infected at 75 percent. Next, airplane samples reached 67 percent contamination, and health center numbers came in at 33 percent.

This study serves as a foundation for new work started about a year ago in her lab.

Marr collaborated with Aaron J. Prussin II, of Blacksburg, Virginia, and they successfully secured for him a postdoctoral fellowship from the Alfred P. Sloan Foundation to characterize the bacterial and viral microbiome — the ecological community of microorganisms — of the air in a daycare center.

They are now attempting to determine seasonal changes of both the viral microbiome and the bacterial microbiome in a daycare setting, and examine how changes in the microbiome are related to naturally occurring changes in the indoor environment.

“Little is known about the viral component of the microbiome and it is important because viruses are approximately 10 times more abundant than bacteria, and they help shape the bacterial community. Research suggests that viruses do have both beneficial and harmful interactions with bacteria,” Prussin said.

With Prussin and Marr working together they hope to verify their hypothesis that daycare centers harbor unique, dynamic microbiomes with plentiful bacteria and viruses. They are also looking at what seasonal changes might bring to a daycare setting.

They pointed to the effect of seasonal changes because in previous work, Marr, her former graduate student Wan Yang, of Shantou, China, and Elankumaran Subbiah, a virologist in the biomedical sciences and pathobiology department of the Virginia-Maryland College of Veterinary Medicine, measured the influenza A virus survival rate at various levels of humidity.

Their 2012 study presented for the first time the relationship between the influenza A virus viability in human mucus and humidity over a large range of relative humidities, from 17 percent to 100 percent. They found the viability of the virus was highest when the relative humidity was either close to 100 percent or below 50 percent. The results in human mucus may help explain influenza’s seasonality in different regions.

According to the news release Marr and her colleagues have developed a fast and cheap technology for detection of airborne pathogens (Note: A link has been removed),

With the urgent need to understand the dynamics of airborne pathogens, especially as one considers the threats of bioterrorism, pandemic influenza, and other emerging infectious diseases, Marr said “a breakthrough technology is required to enable rapid, low-cost detection of pathogens in air.”

Along with Subbiah and Peter Vikesland,  professor of civil and environmental engineering, they want to develop readily deployable, inexpensive, paper-based sensors for airborne pathogen detection.

In 2013 they received funding of almost $250,000 from Virginia Tech’s Institute for Critical Technology and Applied Science, a supporter of the clustering of research groups, to support their idea of creating paper-based sensors based on their various successes to date.

Marr explained the sensors “would use a sandwich approach. The bottom layer is paper containing specialized DNA that will immobilize the virus. The middle layer is the virus, which sticks to the specialized DNA on the bottom layer. The top layer is additional specialized DNA that sticks to the virus. This DNA is attached to gold nanoparticles that are easily detectable using a technique known as Raman microscopy.”

They key to their approach is that it combines high-tech with low-tech in the hopes of keeping the assay costs low. Their sampling method will use a bicycle pump, and low cost paper substrates. They hope that they will be able to incorporate smart-phone based signal transduction for the detection. Using this approach, they believe “even remote corners of the world” would be able to use the technique.

Vikesland previously received funding from the Gates Foundation to detect the polio virus via paper-based diagnostics. Polio is still found in countries on the continents of Asia and Africa.

I have previously mentioned Linsey Marr in an Oct. 18, 2013 post about the revival of the Nanotechnology Consumer Products Inventory (originally developed by the Project for Emerging Nanotechnologies) by academics at Virginia Tech and first mentioned CEINT in an Aug. 15, 2011 post about a special project featuring a mesocosm at Duke University (North Carolina).

Rising from the dead: the inventory of nanotechnology-based consumer products

The inventory of nanotechnology-based consumer products or the Consumer Products Inventory (CPI) is still cited in articles about nanotechnology and its pervasive use in consumer products despite the fact that the inventory was effectively rendered inactive (i.e., dead) in 2009 and that  it was a voluntary system with no oversight, meaning whoever made the submission to the inventory could make any claims they wanted. Now that it’s 2013, things are about to change according to an Oct. 28, 2013 news item on ScienceDaily,

As a resource for consumers, scientists, and policy makers, the Virginia Tech Center for Sustainable Nanotechnology (VTSuN) has joined the Woodrow Wilson International Center for Scholars to renew and expand the Nanotechnology Consumer Product Inventory, an important source of information about products using nanomaterials.

“We want people to appreciate the revolution, such as in electronics and medicine. But we also want them to be informed,” said Nina Quadros, a research scientist at Virginia Tech’s Institute for Critical Technology and Applied Science and associate director of VTSuN, who leads a team of Virginia Tech faculty members and students on this project. Todd Kuiken, senior program associate, and David Rajeski, director of the science and technology innovation program, lead this project at the Wilson Center.

The Oct. 28, 2013 Virginia Tech (Virginia Polytechnic Institute and State University) news release by Susan Trulove (which originated the news item),provides a brief history of the inventory and a description of its revivification,

The Wilson Center and the Project on Emerging Nanotechnology created the inventory in 2005. It grew from 54 to more than 1,000 products, many of which have come and gone. The inventory became the most frequently cited resource, showcasing the widespread applications of nanotechnology. However, in 2009, the project was no longer funded.

“I used it in publications and presentations when talking about all the ways nano is part of people’s lives in consumer products,” said Matthew Hull, who manages the Institute for Critical Technology and Applied Science’s investment portfolio in nanoscale science and engineering, which includes the Center for Sustainable Nanotechnology. “But the inventory was criticized by researchers, regulators, and manufacturers for the lack of scientific information available to support product claims.”

In a meeting with his friend, Andrew Maynard, director of the University of Michigan Risk Science Center, who had initiated the inventory when he was at the Wilson Center, Hull proposed leveraging Institute for Critical Technology and Applied Science and Center for Sustainable Nanotechnology resources to improve the inventory.

“My role was to ask ‘what if’ and [the Virginia Tech Center for Sustainable Nanotechnology] ran with it,” said Hull.

A partnership was formed and, with funding from the Virginia Tech institute, the Center for Sustainable Nanotechnology restructured the inventory to improve the reliability, functionality, and scientific credibility of the database.

“Specifically, we added scientific significance and usefulness by including qualitative and quantitative descriptors for the products and the nanomaterials contained in these products, such as size, concentration, and potential exposure routes,” said Quadros. For example, an intentional exposure route would be the way a medicine is administered. An unintentional exposure would be when a child chews on a toy that has been treated with silver nanoparticles that are used as an antimicrobial. The potential health effect of nanomaterials on children was Quadros doctoral research and she used the inventory to find products designed for children that use nanomaterials, such as plush toys.

“One of the best things about the new version of the inventory is the additional information and the ability to search by product type or the type of nanomaterial,” she said. “When researchers were first attempting to assess the potential environmental impacts of nanotechnology, one main challenge was understanding how these nanomaterials might end up in the environment in the first place. After searching the CPI and seeing the vast applications of nanotechnologies in consumer products it was easier to narrow down scenarios.”

For example, Quadros said many silver nanoparticles are used in clothing for antimicrobial protection, so we can infer that some silver nanoparticles may end up in wastewater treatment plants after clothes washing. This helped justify some of the research on the effects of silver nanoparticle in the biological wastewater treatment processes. Currently, the inventory lists 188 products under the ‘clothing’ category.”

This team also included published scientific data related to those products, where available, and developed a metric to assess the reliability of the data on each inventory entry.

The team interviewed more than 50 nanotechnology experts with more than 350 combined years of experience in nanotechnology, Quadros said. “Their answers provided valuable guidance to help us address diverse stakeholder needs.”

In addition, the site’s users can log in and add information based on their own expertise. “Anyone can suggest edits. The curator and reviewer will approve the edits, and then the new information will go live,” Quadros said.

“We’ve added the horsepower of [the Center for Sustainable Nanotechnology], but opened it by means of crowdsourcing to new information, such as refuting or supporting claims made about products,” Hull said.

“The goal of this work is to create a living, growing inventory for the exchange of accurate information on nano­enabled consumer products,” Quadros said. “Improved information sharing will allow citizens, manufacturers, scientists, policymakers, and others to better understand how nanotechnology is being used in the consumer marketplace,” she said.

As of October 2013,

The inventory currently lists more than 1,600 consumer products that claim to contain nanotechnology or have been found to contain nanomaterials.

Quadros will give a presentation about the inventory at the Sustainable Nanotechnology Organization conference in Santa Barbara on Nov. 3-5 and will present to the U.S. Environmental Protection Agency and the National Science Foundation in the spring.

Key collaborators at Virginia Tech are Sean McGinnis, an associate research professor in the materials science and engineering department; Linsey Marr, professor of civil and environmental engineering; her postdoc, Eric Vejerano, who was instrumental in development of product categories; and Michael Hochella, a university distinguished professor in the geosciences department and Virginia Tech Center for Sustainable Nanotechnology director.

You can find the Consumer Products Inventory here where it is still hosted by the Woodrow Wilson Center’s Project on Emerging Nanotechnologies. The website for the Second Sustainable Nanotechnology Organization Conference where Quadros will be presenting can be found here and is where this conference description can be found,

The objective of this conference is to bring together scientific experts from academia, industry, and government agencies from around the world to present and discuss current research findings on the subject of nanotechnology and sustainability.

The conference program will address the critical aspects of sustainable nanotechnology such as life cycle assessment, green synthesis, green energy, industrial partnerships, environmental and biological fate, and the overall sustainability of engineered nanomaterials. In principle, this involves the fundamental/applied research on the chemistry of producing new green nanomaterials; eco-manufacturing processing of nanomaterials and products, using nanotechnology to benefit society, and examining possible harmful effects of nanotechnology.

The conference will also foster new collaborations between academic and industrial participants. This community of users, researchers and developers of engineered nanomaterials will provide a long-term, scientific assessment of where the science is for sustainable nano, where it should be heading, and what steps academics, government agencies and others can take now to reach targeted goals. In addition, the conference will serve as the platform to initiate the formation of the Sustainable Nanotechnology Organization (SNO), a non-profit, international professional society dedicated to advancing sustainable nanotechnology through education, research, and promotion of responsible development of nanotechnology.

Finally because I can resist no longer, especially so near to Hallowe’en, I guess you could call the ‘renewed’ CPI, a zombie CPI as it’s back from the dead and it needs brains,

Zombies in Moscow, 26 April 2009 Credit: teujene [downloaded from http://en.wikipedia.org/wiki/File:Zombies_in_Moscow.jpg]

Zombies in Moscow, 26 April 2009 Credit: teujene [downloaded from http://en.wikipedia.org/wiki/File:Zombies_in_Moscow.jpg]