Scientists produce nanobodies in plant cells that block emerging pathogens


Scientists at the U.S. Department of Agriculture’s (USDA) Agricultural Research Service (ARS) recently announced that plants could be used to produce nanobodies that quickly block emerging pathogens in human medicine and agriculture. These nanobodies represent a promising new way to treat viral diseases, including SARS-CoV-2.

Nanobodies are small antibody proteins naturally produced in specific animals like camels, alpacas, and llamas.

ARS researchers turned to evaluating nanobodies to prevent and treat citrus greening disease in citrus trees. These scientists are now using their newly developed and patented SymbiontTM technology to show that nanobodies can be easily produced in a plant system with broad agricultural and public health applications.

As a proof-of-concept, researches showed that nanobodies targeting the SARS-CoV-2 virus could be made in plant cells and remain functional in blocking the binding of the SARS-CoV-2 spike protein to its receptor protein: the process responsible for initiating viral infection in human cells.

“We initially wanted to develop sustainable solutions to pathogens in crop production,” said ARS researcher Robert Shatters, Jr. “The results of that research are indeed successful and beneficial for the nation’s agricultural system. But now we are aware of an even greater result—the benefits of producing therapeutics in plants now justify the consideration of using plants to mass produce COVID-19 protein-based therapies.”

AgroSource, Inc. collaborated with USDA-ARS to develop the plant-based production system. They are currently taking the necessary steps to see how they can move this advancement into the commercial sector.

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“This is a huge breakthrough for science and innovative solutions to agricultural and public health challenges,” said ARS researcher Michelle Heck. “This cost-efficient, plant-based system proves that there are alternative ways to confront and prevent the spread of emerging pathogens. The approach has the potential to massively expand livelihood development opportunities in rural agricultural areas of the nation and in other countries.”

The findings are published on the bioRxiv preprint server.

A Titanate Nanowire Mask that can Eliminate Pathogens EPFL Labs


nano wire mask atitanatenan

Filter ‘paper’ made from titanium oxide nanowires is capable of trapping pathogens and destroying them with light. This discovery by an EPFL laboratory could be put to use in personal protective equipment, as well as in ventilation and air conditioning systems.

As part of attempts to curtail the COVID-19 pandemic, paper masks are increasingly being made mandatory. Their relative effectiveness is no longer in question, but their widespread use has a number of drawbacks. These include the environmental impact of disposable masks made from layers of non-woven polypropylene plastic microfibres. Moreover, they merely trap pathogens instead of destroying them. “In a hospital setting, these masks are placed in special bins and handled appropriately,” says László Forró, head of EPFL’s Laboratory of Physics of Complex Matter. “However, their use in the wider world—where they are tossed into open waste bins and even left on the street—can turn them into new sources of contamination.”

Researchers in Forró’s lab are working on a promising solution to this problem: a membrane made of titanium oxide nanowires, similar in appearance to filter paper but with antibacterial and antiviral properties.

Their material works by using the photocatalytic properties of titanium dioxide. When exposed to ultraviolet radiation, the fibers convert resident moisture into oxidizing agents such as hydrogen peroxide, which have the ability to destroy pathogens. “Since our filter is exceptionally good at absorbing moisture, it can trap droplets that carry viruses and bacteria,” says Forró. “This creates a favorable environment for the oxidation process, which is triggered by light.”

The researchers’ work appears today in Advanced Functional Materials, and includes experiments that demonstrate the membrane’s ability to destroy E. coli, the reference bacterium in biomedical research, and DNA strands in a matter of seconds. Based on these results, the researchers assert—although this remains to be demonstrated experimentally—that the process would be equally successful on a wide range of viruses, including SARS-CoV-2.

Their article also states that manufacturing such membranes would be feasible on a large scale: the laboratory’s equipment alone is capable of producing up to 200 m2 of filter paper per week, or enough for up to 80,000 masks per month. Moreover, the masks could be sterilized and reused up a thousand times. This would alleviate shortages and substantially reduce the amount of waste created by disposable surgical masks. Finally, the manufacturing process, which involves calcining the titanite nanowires, makes them stable and prevents the risk of nanoparticles being inhaled by the user.

A start-up named Swoxid is already preparing to move the technology out of the lab. “The membranes could also be used in air treatment applications such as ventilation and air conditioning systems as well as in personal protective equipment,” says Endre Horváth, the article’s lead author and co-founder of Swoxid.

Source.