Tag Archives: Jules Bernstein

Vaccine as a salad

Leave a reply

A research project into growing vaccines in edible plants has been funded at the University of California at Riverside (UCR) according a September 16, 2021 news item on Nanowerk,

The future of vaccines may look more like eating a salad than getting a shot in the arm. UC Riverside scientists are studying whether they can turn edible plants like lettuce into mRNA vaccine factories.

Messenger RNA or mRNA technology, used in COVID-19 vaccines, works by teaching our cells to recognize and protect us against infectious diseases.

One of the challenges with this new technology is that it must be kept cold to maintain stability during transport and storage. If this new project is successful, plant-based mRNA vaccines — which can be eaten — could overcome this challenge with the ability to be stored at room temperature.

The project’s goals, made possible by a $500,000 grant from the National Science Foundation, are threefold: showing that DNA containing the mRNA vaccines can be successfully delivered into the part of plant cells where it will replicate, demonstrating the plants can produce enough mRNA to rival a traditional shot, and finally, determining the right dosage.

Caption: Chloroplasts (magenta) in leaves expressing a green fluorescent protein. The DNA encoding for the protein was delivered by targeted nanomaterials without mechanical aid by applying a droplet of the nano-formulation to the leaf surface. Credit: Israel Santana/UCR

A September 16, 2021 UC Riverside news release (also on EurekAlert) by Jules Bernstein, which originated the news item, provides more information about the project (Note: A link has been removed),

“Ideally, a single plant would produce enough mRNA to vaccinate a single person,” said Juan Pablo Giraldo, an associate professor in UCR’s Department of Botany and Plant Sciences who is leading the research, done in collaboration with scientists from UC San Diego and Carnegie Mellon University. 

“We are testing this approach with spinach and lettuce and have long-term goals of people growing it in their own gardens,” Giraldo said. “Farmers could also eventually grow entire fields of it.”

Key to making this work are chloroplasts — small organs in plant cells that convert sunlight into energy the plant can use. “They’re tiny, solar-powered factories that produce sugar and other molecules which allow the plant to grow,” Giraldo said. “They’re also an untapped source for making desirable molecules.”

In the past, Giraldo has shown that it is possible for chloroplasts to express genes that aren’t naturally part of the plant. He and his colleagues did this by sending foreign genetic material into plant cells inside a protective casing. Determining the optimal properties of these casings for delivery into plant cells is a specialty of Giraldo’s laboratory. 

For this project Giraldo teamed up with Nicole Steinmetz, a UC San Diego professor of nanoengineering, to utilize nanotechnologies engineered by her team that will deliver genetic material to the chloroplasts. 

“Our idea is to repurpose naturally occurring nanoparticles, namely plant viruses, for gene delivery to the plants,” Steinmetz said. “Some engineering goes into this to make the nanoparticles go to the chloroplasts and also to render them non-infectious toward the plants.”

For Giraldo, the chance to develop this idea with mRNA is the culmination of a dream. “One of the reasons I started working in nanotechnology was so I could apply it to plants and create new technology solutions. Not just for food, but for high-value products as well, like pharmaceuticals,” Giraldo said. 

He is also co-leading a related project using nanomaterials to deliver nitrogen, a fertilizer, directly to chloroplasts, where plants need it most. 

Nitrogen is limited in the environment, but plants need it to grow. Most farmers apply nitrogen to the soil. As a result, roughly half of it ends up in groundwater, contaminating waterways, causing algae blooms, and interacting with other organisms. It also produces nitrous oxide, another pollutant. 

This alternative approach would get nitrogen into the chloroplasts through the leaves and control its release, a much more efficient mode of application that could help farmers and improve the environment. 

The National Science Foundation has granted Giraldo and his colleagues $1.6 million to develop this targeted nitrogen delivery technology.

“I’m very excited about all of this research,” Giraldo said. “I think it could have a huge impact on peoples’ lives.”

I wish the researchers the best of luck.

Effective treatment for citrus-destroying disease?

Leave a reply

Citrus greening is a worldwide problem. A particularly virulent disease that destroys citrus fruit, it’s a problem that is worsening. Before getting to the research from the University of California at Riverside (UCR), here’s more about the disease and how it’s developing from the UCR Huanglongbing, (HLB, Citrus Greening webpage,

The Situation: Citrus huanglongbing (HLB), previously called citrus greening disease, is one of the most destructive diseases of citrus worldwide.  Originally thought to be caused by a virus, it is now known to be caused by unculturable phloem-limited bacteria.  There are three forms of greening that have been described.  The African form produces symptoms only under cool conditions and is transmitted by the African citrus psyllid Trioza erytreae, while the Asian form prefers warmer conditions and is transmitted by the Asian citrus psyllid Diaphorina citri.  Recently a third American form transmitted by the Asian citrus psyllid was discovered in Brazil.  This American form of the disease apparently originated in China.  In North America, the psyllid vector, Diaphorina citri, of HLB is found in Florida, Louisiana, Georgia, South Carolina, Texas and Hawaii, and recently arrived in Southern California from Mexico. HLB is known to occur in Florida Lousiana, South Carolina, Georgia, Cuba, Belize and the Eastern Yucatan of Mexico.  A federal quarantine restricts all movement of citrus and other plants in the family Rutaceae from Asian Citrus Psyllid or HLB-infested areas into California in order to prevent introduction of the disease.

 Damage:  The HLB bacteria can infect most citrus cultivars, species and hybrids and even some citrus relatives.  Leaves of newly infected trees develop a blotchy mottle appearance.  On chronically infected trees, the leaves are small and exhibit asymmetrical blotchy mottling (in contrast to Zinc deficiency that causes symmetrical blotching).  Fruit from HLB-infected trees are small, lopsided, poorly colored, and contain aborted seeds. The juice from affected fruit is low in soluble solids, high in acids and abnormally bitter.  The fruit retains its green color at the navel end when mature, which is the reason for the common name “citrus greening disease.”  This fruit is of no value because of poor size and quality.  There is no cure for the disease and rapid tree removal is critical for prevention of spread.

Economic Impact: HLB is one of the most devastating diseases of citrus and since its discovery in Florida in 2005, citrus acreage in that state has declined significantly.  If the disease were to establish in California, the nursery industry would be required to move all of their production under screenhouses, pesticide treatments for the vector would be instituted resulting in greatly increased pesticide costs (3-6 treatments per year) and indirect costs due to pesticide-induced disruption of integrated pest management programs for other citrus pests.  A costly eradication program would need to be instituted to remove infected trees in order to protect the citrus industry.

Distribution of HLB: In April 2012, after about a week of testing, the California Department of Food and Agriculture (CDFA) removed a pumelo tree with a lemon graft from Hacienda Heights in Los Angeles County after the tree and an Asian citrus psyllid found on the tree both tested positive for Huanglongbing. In 2005, HLB was also found in Florida and it is now known to occur in Louisiana, Georgia, South Carolina, Cuba, Belze and Eastern Mexico.  Worldwide, HLB is also present in China, eastern and southern Africa, the Indian subcontinent, Mauritius, Reunion, the Saudi Arabian peninsula, and southeast Asia.

Research:  Research is focusing on characterization of the bacteria, development of detection methods, and control of the disease and the psyllid.  To date, control of the disease is based on planting HLB-free citrus germplasm, eradication of infected citrus plants, and control of the vector with systemic insecticides.  Countries with HLB learn to manage the disease so that they can still produce citrus.  In California, the best strategy is to keep this disease out. This goal is supported by both federal and state quarantine regulations and the University of California’s Citrus Clonal Protection Program, which provides a mechanism for the safe introduction of citrus germplasm into California.

…

A July 7, 2020 news item on phys.org announces what researchers hope can be used commercially as a new treatment for citrus greening disease from researchers University of California at Riverside (UCR), Note: Links have been removed,

UC Riverside scientists have found the first substance capable of controlling Citrus Greening Disease, which has devastated citrus farms in Florida and also threatens California.

The new treatment effectively kills the bacterium causing the disease with a naturally occurring molecule found in wild citrus relatives. This molecule, an antimicrobial peptide, offers numerous advantages over the antibiotics currently used to treat the disease.

UCR geneticist Hailing Jin, who discovered the cure after a five-year search, explained that unlike antibiotic sprays, the peptide is stable even when used outdoors in high heat, easy to manufacture, and safe for humans.

A July 7, 2020 UCR news release (also on EurekAlert) by Jules Bernstein, which originated the news item, provides technical detail and information about plans to commercialize the product,

“This peptide is found in the fruit of Australian finger limes, which can naturally tolerate Citrus Greening bacteria and has been consumed for hundreds of years,” Jin said. “It is much safer to use this natural plant product on agricultural crops than other synthetic chemicals.”

Currently, some growers in Florida are spraying antibiotics and pesticides in an attempt to save trees from the CLas bacterium that causes citrus greening, also known as Huanglongbing or HLB.

“Most antibiotics are temperature sensitive, so their effects are largely reduced when applied in the hot weather,” Jin said. “By contrast, this peptide is stable even when used in 130-degree heat.”

Jin found the peptide by examining plants such as the Australian finger lime known to possess natural tolerance for the bacteria that causes Citrus Greening Disease, and she isolated the genes that contribute to this innate immunity. One of these genes produces the peptide, which she then tested over the course of two years. Improvement was soon visible.

“You can see the bacteria drastically reduced, and the leaves appear healthy again only a few months after treatment,” Jin said.

Because the peptide only needs to be reapplied a few times per year, it is highly cost effective for growers. This peptide can also be developed into a vaccine to protect young healthy plants from infection, as it is able to induce the plant’s innate immunity to the bacteria.

Jin’s peptide can be applied by injection or foliage spray, and it moves systemically through plants and remains stable, which makes the effect of the treatment stronger.

The treatment will be further enhanced with proprietary injection technology made by Invaio Sciences. UC Riverside has entered into an exclusive, worldwide license agreement with Invaio, ensuring this new treatment goes exactly where it’s needed in plants.

“Invaio is enthusiastic to partner with UC Riverside and advance this innovative technology for combating the disease known as Citrus Greening or Huanglongbing,” said Invaio Chief Science Officer Gerardo Ramos. “The prospect of addressing this previously incurable and devastating crop disease, helping agricultural communities and improving the environmental impact of production is exciting and rewarding,” he said. “This is crop protection in harmony with nature.”

The need for an HLB cure is a global problem, but hits especially close to home as California produces 80 percent of all the fresh citrus in the United States, said Brian Suh, director of technology commercialization in UCR’s Office of Technology Partnerships, which helps bring university technology to market for the benefit of society through licenses, partnerships, and startup companies.

“This license to Invaio opens up the opportunity for a product to get to market faster,” Suh said. “Cutting edge research from UCR, like the peptide identified by Dr. Jin, has a tremendous amount of commercial potential and can transform the trajectory of real-world problems with these innovative solutions.”

You can find out more about Invaio Sciences here.

Citrus greening has been featured here before in an April 7, 2015 posting titled, Citrus canker, Florida, and Zinkicide. There doesn’t seem to have been much progress made with this Florida solution for citrus greening. This 2018 document on nano.gov was the most recent I could find, ZinkicideTM- a systemic nano-ZnO based bactericide/fungicide for crop protection by Swadeshmukul Santra.

Chameleon skin (nanomaterial made of gold nanoparticles) for robots

Leave a reply

A June 17, 2020 news item on Nanowerk trumpets research into how robots might be able to sport chameleon-like skin one day,

A new film made of gold nanoparticles changes color in response to any type of movement. Its unprecedented qualities could allow robots to mimic chameleons and octopi — among other futuristic applications.

Unlike other materials that try to emulate nature’s color changers, this one can respond to any type of movement, like bending or twisting. Robots coated in it could enter spaces that might be dangerous or impossible for humans, and offer information just based on the way they look.

For example, a camouflaged robot could enter tough-to-access underwater crevices. If the robot changes color, biologists could learn about the pressures facing animals that live in these environments.

Although some other color-changing materials can also respond to motion, this one can be printed and programmed to display different, complex patterns that are difficult to replicate.

…

This video from the University of California at Riverside researchers shows the material in action (Note: It gets more interesting after the first 20 secs.),

A June 15, 2020 University of California at Riverside (UCR) news release (also on EurekAlert but published on June 17, 2020) by Jules Bernstein, which originated the news item, delves further,

Nanomaterials are simply materials that have been reduced to an extremely small scale — tens of nanometers in width and length, or, about the size of a virus. When materials like silver or gold become smaller, their colors will change depending on their size, shape, and the direction they face.

“In our case, we reduced gold to nano-sized rods. We knew that if we could make the rods point in a particular direction, we could control their color,” said chemistry professor Yadong Yin. “Facing one way, they might appear red. Move them 45 degrees, and they change to green.”

The problem facing the research team was how to take millions of gold nanorods floating in a liquid solution and get them all to point in the same direction to display a uniform color.

Their solution was to fuse smaller magnetic nanorods onto the larger gold ones. The two different-sized rods were encapsulated in a polymer shield, so that they would remain side by side. That way, the orientation of both rods could be controlled by magnets.

“Just like if you hold a magnet over a pile of needles, they all point in the same direction. That’s how we control the color,” Yin said.

Once the nanorods are dried into a thin film, their orientation is fixed in place and they no longer respond to magnets. “But, if the film is flexible, you can bend and rotate it, and will still see different colors as the orientation changes,” Yin said.

Other materials, like butterfly wings, are shiny and colorful at certain angles, and can also change color when viewed at other angles. However, those materials rely on precisely ordered microstructures, which are difficult and expensive to make for large areas. But this new film can be made to coat the surface of any sized object just as easily as applying spray paint on a house.

Though futuristic robots are an ultimate application of this film, it can be used in many other ways. UC Riverside chemist Zhiwei Li, the first author on this paper, explained that the film can be incorporated into checks or cash as an authentication feature. Under normal lighting, the film is gray, but when you put on sunglasses and look at it through polarized lenses, elaborate patterns can be seen. In addition, the color contrast of the film may change dramatically if you twist the film.

The applications, in fact, are only limited by the imagination. “Artists could use this technology to create fascinating paintings that are wildly different depending on the angle from which they are viewed,” Li said. “It would be wonderful to see how the science in our work could be combined with the beauty of art.”

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

Coupling magnetic and plasmonic anisotropy in hybrid nanorods for mechanochromic responses by Zhiwei Li, Jianbo Jin, Fan Yang, Ningning Song & Yadong Yin. Nature Communications volume 11, Article number: 2883 (2020) DOI: https://doi.org/10.1038/s41467-020-16678-8 Published: 08 June 2020

This paper is open access.