Tag Archives: Zika virus

Combat yellow fever mosquito with carbon black nanoparticles?

This April 19, 2022 news item on Nanowerk announces mosquito research from Ohio State University (OSU), Note: A link has been removed,

Before being accidentally introduced to the New World by the 16th century slave trade, the yellow fever mosquito was a species native only to Africa. Highly adaptable, it has since become an invasive species in North America, but researchers at The Ohio State University may have found a way to squash the pesky population in its juvenile stages.
Recently published in the journal Insects (“Larvicidal Activity of Carbon Black against the Yellow Fever Mosquito Aedes aegypti”), a new paper describes how mosquitoes have evolved a natural resistance to some chemical insecticides, and offers an alternative called carbon black, a type of carbon-based nanoparticles, or CNPs [when it’s specifically carbon black nanoparticles, it may sometimes be abbreviated to CBNPs; more about that at the end of this post].

An April 18, 2022 OSU news release (also on EurekAlert), which originated the news item, describes the work in more detail,

Study co-author and an associate professor of entomology at Ohio State, Peter Piermarini described CNPs as “microscopic” materials made out of organic elements. The study used a modified version of carbon black called Emperor 1800, which is often used to coat automobiles black. While CNPs are a relatively new scientific development, they have been considered as new tools to control various insect and pest infestations, he said.
“If we can learn more about how carbon black works and how to use it safely, we could design a commercially available nanoparticle that is highly effective against insecticide-resistant mosquitoes,” Piermarini said.
The yellow fever mosquito, or Aedes aegypti, is a species of mosquito known for spreading not just yellow fever, but also diseases like the Zika virus, dengue fever and chikungunya fever. Adults rarely fly more than a few hundred meters from where they emerge, but their abundance leads to steady transmission of diseases – enough to claim tens of thousands of lives every year and hospitalize hundreds of thousands more people.
Because of this, the mosquito is considered to be one of the deadliest animals on the planet. For this study, the researchers’ goal was to figure out how toxic these nanomaterials could be to mosquito larvae, or the immature form of the insect.
Contrary to popular belief, not all mosquitoes set their sights on turning our blood into their latest meal. Male mosquitoes subsist only on flower nectar; it’s the females that will consume both flower nectar and blood in a bid to provide their eggs with enough protein to grow.
When female mosquitoes are ready to lay their eggs, they return to standing pools of water, like lakes or birdbaths, to release them. After they hatch, these larvae will stay in the water for about a week until they reach adulthood, and take wing.
To test whether Emperor 1800 would be effective in stopping that process, researchers worked with two different strains of the yellow fever mosquito inside the lab, one extremely susceptible to typical chemical insecticides, and the other, extremely resistant to them.
By applying the carbon black nanomaterials to the water during the earliest stages of the mosquito’s life cycle and checking in 48 hours later, they were able to determine that CNPs kill mosquito larvae both quickly and efficiently.
“Given the properties of carbon black, it has the most potential for killing larvae because it can be suspended in water,” Piermarini said. Their findings showed that the material seemed to accumulate on the mosquito larvae’s head, abdomen, and even in its gut, meaning that at some point, the larvae were ingesting smaller particles of carbon black.
“Our hypothesis is that these materials may be physically obstructing their ability to perform basic biological functions. It could be blocking their digestion, or might be interfering with their ability to breathe,” said Piermarini.
However, there was one thing that Piermarini found particularly surprising.
When first suspended in water, carbon black appeared equally toxic to larvae of insecticide-resistant and insecticide-susceptible mosquitoes, but the longer the carbon black was suspended in water before treating them. it became more toxic to the insecticide-resistant larvae.
“When you first apply the CNP solution it has similar toxicity against both strains,” Piermarini said. “But when you let the suspension age for a few weeks, it tends to become more potent against the resistant strain of mosquitoes.”
Although they couldn’t determine the reason behind the time-lapsed deaths, the study concluded that these new nanomaterials could be extremely beneficial to controlling the species when applied as a preventive treatment to mosquito breeding grounds.
But before it can be utilized by the public, Piermarini said, carbon black needs to undergo rigorous testing to ensure it won’t harm humans and the environment as a whole.
Co-authors were Erick Martinez Rodriguez, a visiting scholar currently in the Ohio State Entomology Graduate program, Parker Evans, a previous PhD student in the Ohio State Translational Plant Sciences Graduate program, and Megha Kalsi, a previous postdoctoral researcher in entomology. This research was supported by Ohio State’s College of Food, Agricultural, and Environmental Sciences and Vaylenx LLC.

Here’s a link to and a citation for the paper,

Larvicidal Activity of Carbon Black against the Yellow Fever Mosquito Aedes aegypti by Erick J. Martínez Rodríguez, Parker Evans, Megha Kalsi, Noah Rosenblatt, Morgan Stanley, and Peter M. Piermarini. Insects 2022, 13(3), 307 DOI: https://doi.org/10.3390/insects13030307 Published: 20 March 2022

The paper appears to be open access.

The naming of things

The nomenclature for carbon at the nanoscale is a little confusing to me. As best as I can determine all of the elements have multiple names at the nanoscale but it’s only with carbon that subcategories function as categories themselves. For example, fullerenes (C60s), single-walled carbon nanotubes (SWCNTs), double-walled carbon nanotubes (DWCNTs), and mulit-walled carbon nanotubes (MWCNTs) are subcategories that stand on their own but, sometimes, are referred to as carbon nanoparticles, which is the main category. I checked carbon black nanoparticles online and found a number of instances where it was abbreviated to CBNP and it can also be a CNP since it is found under the carbon nanoparticle category as per this Wikipedia entry.

Spotting the difference between dengue and Zika infections with gold nanosensors

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This July 29, 2020 news item on Nanowerk features research from Brazil,

A new class of nanosensor developed in Brazil could more accurately identify dengue and Zika infections, a task that is complicated by their genetic similarities and which can result in misdiagnosis.
The technique uses gold nanoparticles and can “observe” viruses at the atomic level, according to a study published in Scientific Reports (“Nanosensors based on LSPR are able to serologically differentiate dengue from Zika infections”).
Belonging to the Flavivirus genus in the Flaviviridae family, Zika and dengue viruses share more than 50 per cent similarity in their amino acid sequence. Both viruses are spread by mosquitos and can have long-term side effects. The Flaviviridae virus family was named after the yellow fever virus and comes from the Latin word for golden, or yellow, in colour.
“Diagnosing [dengue virus] infections is a high priority in countries affected by annual epidemics of dengue fever. The correct diagnostic is essential for patient managing and prognostic as there are no specific antiviral drugs to treat the infection,” the authors say.
More than 1.8 million people are suspected to have been infected with dengue so far this year in the Americas, with 4000 severe cases and almost 700 deaths, the Pan American Health Organization says. The annual global average is estimated to be between 100 million and 400 million dengue infections, according to the World Health Organization.
Flávio Fonseca, study co-author and researcher at the Federal University of Minas Gerais, tells SciDev.Net it is almost impossible to differentiate between dengue and Zika viruses.
“A serologic test that detects antibodies against dengue also captures Zika-generated antibodies. We call it cross-reactivity,” he says.
…

Meghie Rodrigues’ July 29, 2020 article for SciDev.net, which originated the news item, delves further into the work,

Co-author and virologist, Maurício Nogueira, tells SciDev.Net that avoiding cross-reactivity is crucial because “dengue is a disease that kills — and can do so quickly if the right diagnosis is not made. As for Zika, it offers risks for foetuses to develop microcephaly, and we can’t let pregnant women spend seven or eight months wondering whether they have the virus or not.”
There is also no specific antiviral treatment for Zika and the search for a vaccine is ongoing.
Virus differentiation is important to accurately measure the real impact of both diseases on public health. The most widely used blood test, the enzyme-linked immunosorbent assay (ELISA), is limited in its ability to tell the difference between the viruses, the authors say.
As dengue has four variations, known as serotypes, the team created four different nanoparticles and covered each of them with a different dengue protein. They applied ELISA serum and a blood sample. The researchers found that sample antibodies bound with the viruses’ proteins, changing the pattern of electrons on the gold nanoparticle surface.
…

Should you check out Rodrigues’ entire article, you might want to take some time to explore SciDev.net to find science news from countries that don’t often get the coverage they should.

Here’s a link to and a citation for the researchers’ paper,

Nanosensors based on LSPR are able to serologically differentiate dengue from Zika infections by Alice F. Versiani, Estefânia M. N. Martins, Lidia M. Andrade, Laura Cox, Glauco C. Pereira, Edel F. Barbosa-Stancioli, Mauricio L. Nogueira, Luiz O. Ladeira & Flávio G. da Fonseca. Scientific Reports volume 10, Article number: 11302 (2020) DOI: https://doi.org/10.1038/s41598-020-68357-9 Published: 09 July 2020

This paper is open access.

Nanotechnology-enabled dengue virus vaccine

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Here’s news of work-in-progress for a dengue virus vaccine and, possibly, a Zika virus vaccine too. From a Nov. ??, 2016 University of North Carolina news release,

Scientists at the UNC School of Medicine are working to develop a nanoparticle vaccine to protect against the four serotypes of dengue virus, which infects more than 350 million people across the globe each year.

Aravinda de Silva, PhD, professor of microbiology and immunology, and a post-doctoral researcher Stefan Metz, PhD, recently published the latest on their vaccine development efforts in PLOS Neglected Tropical Diseases.

The nanoparticle platform was produced with PRINT (Particle Replication in Non-wetting Templates) technology. Joseph DeSimone, PhD, the Chancellor’s Eminent Professor of Chemistry and a joint professor in the Department of Pharmacology at UNC, developed PRINT, a nano-molding technique, in 2004.

Rather than using a killed or attenuated virus to develop a vaccine for dengue, de Silva’s lab is focusing on “expressing the E protein and attaching it to nanoparticles to induce good immune responses,” Metz said.

The nanoparticle vaccine platform can be safer to certain populations than vaccines that use either live or killed virus, he said.

One of the many complexities about developing a successful dengue vaccine, Metz explained, is that there are four serotypes of the virus, which means researchers need to develop a vaccine that provides immunity against all four serotypes.

“There are currently several vaccines in trial and development for dengue,” Metz said. “One vaccine has gone through all three clinical trial phases and has been licensed in some countries. Although these vaccines produce good antibody responses, a large part of the population still wasn’t protected from each of the serotypes.

“With dengue, you need to vaccinate people against all four serotypes at once in order to protect people. That’s why we’re combing the different serotypes.”

In their most recent study, de Silva and Metz focused their efforts on the second serotype. Now, they’re moving forward with the same studies for serotypes one, three and four.

“In the study, we express the E protein, which is found on the surface of the virus particle,” Metz explained. “This protein is organized in a very complex way, and this complex organization exposes isotopes that are important to induce protective immune response.”

De Silva and Metz were recently named to a global research consortium to tackle Zika, and they’re using the same nanoparticle vaccine platform as they work to develop a Zika vaccine.

“Globally, if you look at the numbers, dengue is still a much bigger problem than Zika,” Metz said, noting that an estimated 25,000 people die from dengue infections each year. “If you get dengue, you might not even notice it. If you do get clinical symptoms during a first infection of dengue, you might feel like you have a feverish flu. A lot of people don’t even know it because if you’re not feeling well for a couple days, you don’t necessarily think that it’s caused by a dengue virus infection.

“However, if you were infected by the first serotype and you had a secondary infection with a different serotype, that’s when the more severe diseases can come up – stress syndromes, hemorrhagic diseases – those can be fatal diseases,” Metz said. “There are thousands and thousands of people dying from those diseases each year.”