Tag Archives: Vivek Kumar

Nano-enabled precision delivery methods for agriculture

A July 23, 2024 news item on Nanowerk provides an introduction to nanoparticles and their potential use in agriculture, Note: Links have been removed,

Nanoparticles could potentially help address agricultural and environmental sustainability issues on a global scale.

Those issues include rising food demand, increasing greenhouse gas emissions generated by agricultural activities, climbing costs of agrochemicals, reducing crop yields induced by climate change, and degrading soil quality. A class of nanoscale particles called “nanocarriers” could make crop agriculture more sustainable and resilient to climate change, according to a group of specialists that includes Kurt Ristroph, assistant professor of agricultural and biological engineering at Purdue University.

“Saying ‘nanoparticle’ means different things to different people,” Ristroph said. In nanodrug delivery, a nanoparticle usually ranges in size from 60 to 100 nanometers and is made of lipids or polymers. “In the environmental world, a nanoparticle usually means a 3- to 5-nanometer metal oxide colloid. Those are not the same thing, but people use ‘nanoparticle’ for both.”

Ristroph helped organize a 2022 interdisciplinary workshop on nanomethods for drug delivery in plants. Funded by the National Science Foundation and the U.S. Department of Agriculture, the workshop was attended by 30 participants from academia, industry and government laboratories.

Many of the workshop participants, including Ristroph, have now published their conclusions in Nature Nanotechnology (“Towards realizing nano-enabled precision delivery in plants”). Their article reviews the possibility nanocarriers could make crop agriculture more sustainable and resilient to climate change.

A July 23, 2024 Purdue University news release (also on EurekAlert but published July 19, 2024) by Steve Koppes, which originated the news item, delves further into the topic of how agriculture could be made more sustainable with nanotechnology-enabled delivery methods, Note: Links have been removed,

“Nano-enabled precision delivery of active agents in plants will transform agriculture, but there are critical technical challenges that we must first overcome to realize the full range of its benefits,” said the article’s co-lead author Greg Lowry, the Walter J. Blenko, Sr. Professor of Civil and Environmental Engineering at Carnegie Mellon University. “I’m optimistic about the future of plant nanobiotechnology approaches and the beneficial impacts it will have on our ability to sustainably produce food.”

Plant cells and human cells have major physiological differences. Plant cells have a cell wall while human cells don’t, for example. But certain tools can be transferred from nanomedicine to plant applications.

“People have developed tools for studying the bio-corona formation around nanoparticles in an animal. We could think about bringing some of those tools to bear on nanoparticles in plants,” Ristroph said. 

When nanoparticles are injected into the bloodstream, many components of the blood stick onto the surface of the nanoparticles. The various proteins sticking to a nanoparticle’s surface make it look different.

The task then becomes figuring out what proteins or other molecules will stick to the surface and where the particle will go as a result. A nanoparticle designed to move toward a certain organ may have its destination altered by white blood cells that detect the particle’s surface proteins and send it to a different organ.

“Broadly speaking, that’s the idea of bio-corona formation and trafficking,” Ristroph said. “People in drug delivery nanomedicine have been thinking about and developing tools for studying that kind of thing. Some of those thoughts and some of those tools could be applied to plants.” 

Researchers already have developed many different architectures and chemistries for making nanoscale delivery vehicles for nanomedicine. “Some of the particle types are transferable,” he said. “You can take a nanoparticle that was optimized for movement in humans and put it in a plant, and you’ll probably find that it needs to be redesigned at least somewhat.”

Ristroph focuses on organic (carbon-based) nanocarriers that have a core-shell structure. The core contains a payload, while the shell forms a protective outer layer. Researchers have used many different types of nanomaterial in plants. The most popular materials are metallic nanoparticles because they are somewhat easier to make, handle and track where they go in a plant than organic nanoparticles.

“One of the first questions that you want to figure out is where these nanoparticles go in a plant,” Ristroph said. “It’s a lot easier to detect a metal inside of a plant that’s made of carbon than it is to detect a carbon-based nanoparticle in a plant that’s made of carbon.”

Last March, Ristroph and Purdue PhD student Luiza Stolte Bezerra Lisboa Oliveira published a critical review of the research literature on the Uptake and Translocation of Organic Nanodelivery Vehicles in Plants in Environmental Science and Technology.

“Not a lot is understood about transformations after these things go into a plant, how they’re getting metabolized,” Ristroph said. His team is interested in studying that, along with ways to help ensure that the nanoparticles are delivered to their proper destinations, and in corona formation. Coronas are biomolecular coatings that affect nanoparticle functions. 

The manufacturability of nanocarriers is another interest area that could be transferred to agriculture from nanomedicine.

“I care a lot about manufacturability and making sure that whatever techniques we’re using to make the nanoparticles are scalable and economically feasible,” Ristroph said.

The manufacturability of nanocarriers is another interest area that could be transferred to agriculture from nanomedicine.

“I care a lot about manufacturability and making sure that whatever techniques we’re using to make the nanoparticles are scalable and economically feasible,” Ristroph said.

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

Towards realizing nano-enabled precision delivery in plants by Gregory V. Lowry, Juan Pablo Giraldo, Nicole F. Steinmetz, Astrid Avellan, Gozde S. Demirer, Kurt D. Ristroph, Gerald J. Wang, Christine O. Hendren, Christopher A. Alabi, Adam Caparco, Washington da Silva, Ivonne González-Gamboa, Khara D. Grieger, Su-Ji Jeon, Mariya V. Khodakovskaya, Hagay Kohay, Vivek Kumar, Raja Muthuramalingam, Hanna Poffenbarger, Swadeshmukul Santra, Robert D. Tilton & Jason C. White. Nature Nanotechnology (2024) DOI: https://doi.org/10.1038/s41565-024-01667-5 Published: 06 June 2024

This paper is behind a paywall.

Snake venom as a healing agent in hydrogels

The Brazilian lancehead is one of several South American pit vipers that produce venom that has proven to be a powerful blood coagulant. Scientists at Rice University have combined a derivative of the venom with their injectable hydrogels to create a material that can quickly stop bleeding and protect wounds, even in patients who take anti-coagulant medications. (Credit: Photo by Greg Hume via Wikipedia)

The Brazilian lancehead is one of several South American pit vipers that produce venom that has proven to be a powerful blood coagulant. Scientists at Rice University have combined a derivative of the venom with their injectable hydrogels to create a material that can quickly stop bleeding and protect wounds, even in patients who take anti-coagulant medications. (Credit: Photo by Greg Hume via Wikipedia)

Mesmerizing and beautiful in their way, venomous snakes are healers, as well as, killers. An Oct. 27, 2015 news item on Azonano describes a new healing use for their venom,

A nanofiber hydrogel infused with snake venom may be the best material to stop bleeding quickly, according to Rice University scientists.

The hydrogel called SB50 incorporates batroxobin, a venom produced by two species of South American pit viper. It can be injected as a liquid and quickly turns into a gel that conforms to the site of a wound, keeping it closed, and promotes clotting within seconds.

An Oct. 26, 2015 Rice University news release, which originated the news item, provides more details (Note: Links have been removed),

Rice chemist Jeffrey Hartgerink, lead author Vivek Kumar and their colleagues reported their discovery in the American Chemical Society journal ACS Biomaterials Science and Engineering. The hydrogel may be most useful for surgeries, particularly for patients who take anti-coagulant drugs to thin their blood.

“It’s interesting that you can take something so deadly and turn it into something that has the potential to save lives,” Hartgerink said.

Batroxobin was recognized for its properties as a coagulant – a substance that encourages blood to clot – in 1936. It has been used in various therapies as a way to remove excess fibrin proteins from the blood to treat thrombosis and as a topical hemostat. It has also been used as a diagnostic tool to determine blood-clotting time in the presence of heparin, an anti-coagulant drug.

“From a clinical perspective, that’s far and away the most important issue here,” Hartgerink said. “There’s a lot of different things that can trigger blood coagulation, but when you’re on heparin, most of them don’t work, or they work slowly or poorly. That obviously causes problems if you’re bleeding.

“Heparin blocks the function of thrombin, an enzyme that begins a cascade of reactions that lead to the clotting of blood,” he said. “Batroxobin is also an enzyme with similar function to thrombin, but its function is not blocked by heparin. This is important because surgical bleeding in patients taking heparin can be a serious problem. The use of batroxobin allows us to get around this problem because it can immediately start the clotting process, regardless of whether heparin is there or not.”

The batroxobin combined with the Rice lab’s hydrogels isn’t taken directly from snakes, Hartgerink said. The substance used for medicine is produced by genetically modified bacteria and then purified, avoiding the risk of other contaminant toxins.

The Rice researchers combined batroxobin with their synthetic, self-assembling nanofibers, which can be loaded into a syringe and injected at the site of a wound, where they reassemble themselves into a gel.

Tests showed the new material stopped a wound from bleeding in as little as six seconds, and further prodding of the wound minutes later did not reopen it. The researchers also tested several other options: the hydrogel without batroxobin, the batroxobin without the hydrogel, a current clinical hemostat known as GelFoam and an alternative self-assembling hemostat known as Puramatrix and found that none were as effective, especially in the presence of anti-coagulants.

The new work builds upon the Rice lab’s extensive development of injectable hydrogel scaffolds that help wounds heal and grow natural tissue. The synthetic scaffolds are built from the peptide sequences to mimic natural processes.

“To be clear, we did not discover nor do any of the initial investigations of batroxobin,” Hartgerink said. “Its properties have been well-known for many decades. What we did was combine it with the hydrogel we’ve been working on for a long time.

“We think SB50 has great potential to stop surgical bleeding, particularly in difficult cases in which the patient is taking heparin or other anti-coagulants,” he said. “SB50 takes the powerful clotting ability of this snake venom and makes it far more effective by delivering it in an easily localized hydrogel that prevents possible unwanted systemic effects from using batroxobin alone.”

SB50 will require FDA approval before clinical use, Hartgerink said. While batroxobin is already approved, the Rice lab’s hydrogel has not yet won approval, a process he expects will take several more years of testing.

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

Nanofibrous Snake Venom Hemostat by Vivek A. Kumar, Navindee C. Wickremasinghe, Siyu Shi, and Jeffrey D. Hartgerink. ACS Biomater. Sci. Eng., Article ASAP
DOI: 10.1021/acsbiomaterials.5b00356 Publication Date (Web): October 22, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.