Culture

Spider venom key to pain relief without side-effects

Molecules in tarantula venom could be used as an alternative to opioid pain killers for people seeking chronic pain relief.

University of Queensland researchers have designed a novel tarantula venom mini-protein that can potentially relieve severe pain without addiction.

Dr Christina Schroeder from UQ's Institute for Molecular Bioscience said the current opioid crisis around the world meant urgent alternatives to morphine and morphine-like drugs, such as fentanyl and oxycodone, were desperately needed.

"Although opioids are effective in producing pain relief, they come with unwanted side-effects like nausea, constipation and the risk of addiction, placing a huge burden on society," Dr Schroeder said.

"Our study found that a mini-protein in tarantula venom from the Chinese bird spider, known as Huwentoxin-IV, binds to pain receptors in the body.

"By using a three-pronged approach in our drug design that incorporates the mini-protein, its receptor and the surrounding membrane from the spider venom, we've altered this mini-protein resulting in greater potency and specificity for specific pain receptors.

"This ensures that just the right amount of the mini-protein attaches itself to the receptor and the cell membrane surrounding the pain receptors."

Dr Schroeder said the mini-protein had been tested in mouse models and shown to work effectively.

"Our findings could potentially lead to an alternative method of treating pain without the side-effects and reduce many individuals' reliance on opioids for pain relief," she said.

Credit: 
University of Queensland

Skoltech researchers find a new HIT defense bacteria use against antibiotics

Scientists at the Severinov Laboratory in Skoltech and their colleagues from Russia and the US have uncovered a new mechanism of bacterial self-defense against microcin C, a potent antibiotic weapon in the microscopic world that can sometimes turn on its master.

Microcin C is a peptide-nucleotide antibiotic produced by some strains of Escherichia coli. It is essentially a Trojan horse: its peptide part helps it get into a cell, where the cell's own internal machinery turns it into what's called "processed McC". This compound completely blocks protein biosynthesis by interfering with its crucial component, aspartyl-tRNA synthetase.

Unfortunately for the microcin C producer, some of the "Greeks" in this metaphor inevitably escape from the "horse" too early, while it is still inside the producing cell, which leads to self-intoxication. That is why the producing cell has to get creative in developing defenses against its own weapon; one of these defenses is an enzyme that acetylates processed McC, rendering it useless.

Skoltech PhD student Eldar Yagmurov and his colleagues have found another way cells can protect themselves -- histidine-triad (HIT) superfamily hydrolases (that is, enzymes that break a larger molecule into smaller ones using water).

"HIT hydrolases have long been suspected to be involved in the mechanisms of self-defense against microcin C. One particular enzyme in this family is known to break the bond between phosphorus and nitrogen that connects the two parts in a complex very similar to McC -- so we figured there might be some other member of the superfamily that can work against microcin C," says Yagmurov.

The researchers used bioinformatics to predict a cluster in the genome of Hyalangium minutum, a Gram-negative bacterium, that encodes the production of its McC-like compounds and a particular HIT superfamily phosphoramidase that they suspected might provide self-immunity to these antibiotics. Experiments showed that this was indeed true: the enzyme apparently destroys the bond between the "transport" and "warhead" parts of processed McC, deactivating the latter.

"By studying the naturally existing means of antibiotic resistance, especially for a promising antimicrobial agent such as McC, we can try to be one step ahead of the bacteria and modify the antibiotic in a way that would help it evade these natural defenses", Yagmurov adds.

According to the paper, other bacteria may have their own analogues of the H. minutum HIT enzyme, each protecting against a specific McC-like compound that they use to survive in the tough bacterial world. This also implies a plethora of yet-unidentified McC-like compounds, some of which may have the potential to become practically used antibiotics of the future.

Credit: 
Skolkovo Institute of Science and Technology (Skoltech)

COVID-19: Cedars-Sinai physician co-authors analysis of antiviral drug

LOS ANGELES (April 11, 2020) -- In a small group of patients hospitalized with severe complications of COVID-19 and treated with the experimental antiviral drug remdesivir, clinical improvement was observed in 68% of patients treated, according to an analysis co-authored by Jonathan Grein, MD, director of Hospital Epidemiology at Cedars-Sinai.

The experimental therapy was given to patients through a "compassionate use" program that allows providers access to treatments not yet approved by the Food and Drug Administration when a patient has a life-threatening condition and no other options are available.

The analysis, published online today by The New England Journal of Medicine, evaluated data from 53 patients in the U.S, Europe, Canada and Japan who received at least one dose of remdesivir by March 7. The effort was led by Gilead Sciences, the pharmaceutical company that makes the experimental drug.

The study shows:

68% of patients treated with remdesivir demonstrated an improvement in the level of oxygen support they needed over a median follow-up of 18 days from the first dose of the drug.

Of the 34 patients who had been intubated and required support from mechanical ventilators (breathing machines), 57% had their breathing tubes taken out.

47% of all patients were discharged from the hospital following treatment with remdesivir

"Currently there is no proven treatment for COVID-19. We cannot draw definitive conclusions from these data, but the observations from this group of hospitalized patients who received remdesivir are hopeful," said Grein, who also leads the Special Pathogens Response Team at Cedars-Sinai. "We look forward to the results of controlled clinical trials to potentially validate these findings."

Cedars-Sinai is continuing to explore remdesivir as a therapeutic option for patients as part of a large international randomized controlled study sponsored by the NIH.

Compassionate use programs are less stringent than a randomized controlled study, which compares patients who are receiving the experimental treatment to patients receiving the standard treatment. However, during the COVID-19 pandemic, compassionate use data can help scientists understand potential risks and can offer a glimpse into whether an experimental treatment might or might not be viable.

"It's critical that the medical community finds a safe and effective treatment for COVID-19 that's supported by solid data," Grein said. "I'm very proud that Cedars-Sinai is contributing to the global effort to find that solution."

Credit: 
Cedars-Sinai Medical Center

Details of treatment for patients in China who died of COVID-19

What The Study Did: This case series describes clinical characteristics of patients who died of coronavirus disease 2019 (COVID-19) in China.

Authors: Haibo Qiu, M.D., Ph.D., of Zhongda Hospital, Southeast University in Jiangsu, China, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamanetworkopen.2020.5619)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflicts of interest and financial disclosures, and funding and support.

Credit: 
JAMA Network

Caring for patients with cancer during the COVID-19 outbreak in Italy

What The Article Says: An essay discusses the challenges associated with caring for patients with cancer during the COVID-19 epidemic in Italy.

Authors: Filippo Pietrantonio, M.D., and Marina Chiara Garassino, M.D., of the Fondazione IRCCS Istituto Nazionale dei Tumori in Milan, are the authors.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamaoncol.2020.1426)

Editor's Note: The article includes conflict of interest disclosures. Please see the articles for additional information, including other authors, author contributions and affiliations, conflicts of interest and financial disclosures, and funding and support.

Credit: 
JAMA Network

Neurologic manifestations of hospitalized patients with COVID-19

What The Study Did: This study investigates the neurologic symptoms of patients with coronavirus disease 2019 (COVID-19) in Wuhan, China.

Authors: Bo Hu, M.D., Ph.D., and Yanan Li, M.D., Ph.D., of Union Hospital, Tongji Medical College, Huazhong University of Science and Technology in Wuhan, China, are the corresponding authors.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamaneurol.2020.1127)

Editor's Note: The article includes funding/support disclosures. Please see the articles for additional information, including other authors, author contributions and affiliations, conflicts of interest and financial disclosures, and funding and support.

Credit: 
JAMA Network

Mental health consequences of COVID-19, physical distancing

What The Viewpoint Says: The article emphasizes the importance of mitigating the mental health consequences of social distancing in the COVID-19 era.

Authors: Sandro Galea, M.D., of the Boston University School of Public Health, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamainternmed.2020.1562)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflicts of interest and financial disclosures, and funding and support.

Credit: 
JAMA Network

Suicide mortality and COVID-19

What The Viewpoint Says: Reasons why U.S. suicide rates may rise in tandem with the coronavirus disease 2019 (COVID-19) pandemic are explained in this article that also describes opportunities to expand research and care.

Authors: Mark A. Reger, Ph.D., of the VA Puget Sound Health Care System, and  Seattle, Washington; and the University of Washington in Seattle, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamapsychiatry.2020.1060)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Credit: 
JAMA Network

Working together to combat mental health challenges during COVID-19 pandemic

What The Viewpoint Says: This article offers lessons from Hubei, China, on potential methods to focus on mental health during the coronavirus disease 2019 (COVID-19) pandemic.

Authors: Yu-Tao Xiang, M.D., Ph.D., of the University of Macau in the Macao Special Administrative Region, China, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamapsychiatry.2020.1057)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Credit: 
JAMA Network

What is the origin of water on Earth?

While everybody agrees that our blue planet is rich in water, this observation is at odd, first, with the exploration of other rocky planets, genuinely lacking surface water, and second, with the idea of a giant impact between the proto-Earth and a planetary embryo the size of Mars that created the Moon. Such a catastrophic event should have vaporized any pre-existing water, leaving behind a dry Earth. After the giant impact catastrophe, we have thus two options to explain the presence of water on Earth : either water was brought back later, after the catastrophe, notably by icy or water-rich asteroids; or the giant impact was not big enough to vaporize all the water on Earth.

Because of the importance of water to sustain life, the question of the origin of water on Earth is primordial. A major challenge in investigating this question is that Earth has lost all the traces of its formation since it is an active planet.

A team of numerical modelers and geochemists led by Cédric Gillmann - Université libre de Bruxelles, ULB, funded by the EoS project ET-HoME - has decided to look far beyond Earth - up to Venus - to investigate the origin of terrestrial water.

While Earth and Venus could be considered as twin sisters, their respective geological and climatic evolutions diverged dramatically in the past, leading to Venus' present-day 92 bar atmosphere heated by an infernal greenhouse up to 470°C, opposed to the mild conditions and only 1 bar pressure at the surface of Earth.

However, Venus' volcanic activity and outgassing are reduced compared to Earth, because it has no plate tectonics, but has a stagnant lid instead. Even better, such a convection mode implies very little recycling of volatile species into the mantle.

As such, despite being an inferno, the evolution of the atmosphere of Venus is much easier to understand and model over geological times. In addition, because of their proximity, the Earth and Venus should have received the same type of material during their history. All these aspects combine to make Venus a perfect place to study the primitive evolution of terrestrial planets.

Using numerical simulations of impacts of different types of asteroids containing various amount of water, the team has discovered that water-rich asteroids colliding with Venus and releasing their water as vapor cannot explain the composition of Venus atmosphere as we measure it today. It means that the asteroidal material that came to Venus, and thus to Earth, after the giant impact must have been dry, therefore preventing the replenishment of the Earth in water.

Because water can obviously be found on our planet today, it means that the water we are now enjoying on Earth has been there since its formation, likely buried deep in the Earth so it could survive the giant impact.

This idea has very deep implications in terms of habitability of ancient Earth, Venus and Mars, as it suggests that planets likely formed with their near-full budget in water, and slowly lost it with time. Because Mars is much smaller, it likely lost all its water while life developed on Earth. For Venus, those results shine a complementary light on recent work advocating that water oceans existed at the surface of the planet, and help constrain the maximum amount of water that can be expected on Venus. They will also help prepare the next generation of space missions to Venus.

Credit: 
Université libre de Bruxelles

Ants or plants? Evolutionary diversification factors of aphids

image: Stomaphis yanonis being cared for by Lasius ants.

Image: 
Yoshiyuki Matsumoto of Shibaura Institute of Technology Kashiwa Junior and Senior High School, Japan

One of the major objectives in biology is to understand the factors and mechanisms that have led to the diversification of species on earth. Plant-feeding insects are the most diversified group of organisms on earth, and they account for more than 40% of all insects. There have been numerous studies into the diversification patterns and driving forces looking at host plants, however, interactions with other organisms had yet to be accounted for.

The study Evolutionary diversification of Japanese Stomaphis aphids (Aphididae, Lachninae) in relation to their host plant use and ant association, set out to understand the driving force that generated evolutionary diversification of the plant-feeding, ant-associated Stomaphis aphid through their long evolutionary history. Aphids are known to have established a mutualistic relationship with ants by providing them with honeydew in exchange for protection from their natural enemies and receiving hygienic services. Aphids are relatively large and remain sedentary due to their need to suck sap from tree trunks.

Scientists have long thought that diversity was a result of aphids shifting their host plants to other closely related plant species. Or did they diversify through a shift of mutualistic partners such as body guard ants? Some aphid traits, morphological (structural) and behavioral have evolved to serve their relationship with ants better. For example, the shape and color of aphid bodies are known to suit the type of ant they have a symbiotic relationship with. Aphids and their mutualistic relationship with ants is so ingrained to their lives, they cannot survive without them. The question is, which had a stronger influence on the aphids diversification? The host plants, or mutualistic ants? The relative importance of host plants and mutualistic partners in structuring evolutionary diversification of a group of insects had yet to be fully investigated.

The research group lead by Tetsuya Yamamoto and Takao Itino of Shinshu University studied 160 Stomaphis aphid colonies at 34 sites in Japan to find out. Currently there have been 33 species and 4 subspecies of Stomaphis aphids described world-wide. Most are specific to one plant species or genus. The researchers searched for known host plants and followed Lasius ant trails to find the aphid colonies. The researchers then examined the mitochondrial DNA using Bayesian information criterion. This is a method of interpreting probability, and scientists get insight into the most likely lineages based on the mitochondrial and nuclear sequences. The scientists were able to identify 38 haplotypes of the aphids by using molecular phylogenetic analysis. They found that evolutionary diversification of Stomaphis aphids was generated primarily through host plant shifts, rather than associated ant species because there was a high degree of specificity between of each lineage and haplotype of Stomaphis aphids to their host plant species with no overlap, while almost all lineages of Stomaphis aphids were associated with two or more ant species.

Although the group showed that Stomaphis aphids evolutionarily diversified through host plant shifts, the remarkable finding that came as a surprise was that Stomaphis aphids had not shifted between closely related plant species, but between very distantly related host plant taxa. Even to different plant orders, from oaks to pine trees! It is very unusual to observe such insect host shifts between very distantly related host plant taxa.

The group hope to continue research to find the factors responsible for the host specificity of Stomaphis aphids. They hypothesize that the dependence of Stomaphis on long-lasting Lasius ant colonies situated in temperate deciduous forests where Lasius is the dominant ant genus may have led the aphids to shift to distantly related but spatially adjacent host tree species so they can potentially feed on both. Their ultimate goal is to better understand the role of ants and plants that shape plant-feeding insect evolution.

Credit: 
Shinshu University

Hair surface engineering to be advanced by nano vehicles

"Hair surface engineering: modification of fibrous materials of biological origin using functional ceramic nano containers", a project headed by Rawil Fakhrullin, is supported by the Russian Science Foundation.

Dr. Fakhrullin explains, "We will modify the surface of hair and other fibrous materials of natural origin by the directed formation of nano-structured layers based on functional inorganic ceramic nano containers carrying a variety of organic components. Materials of natural origin are hypoallergenic, comfortable to use, but they have rather low wear resistance, and they are prone to deformation and biodegradation. Directed modification of properties using functionalized nano materials will significantly expand the field of application of natural fibers."

Based on the close similarity of the microstructure of fibrous materials of natural origin and mammalian hair, the scientists are going to create a universal technology for modifying the surface of fibers of biological origin for use in the textile and cosmetic industries.

&laquoBy modifying the fibrous structures of natural origin, it will be possible to change their aesthetic properties (color, texture and smell), protect them from biodegradation by applying antibacterial, fungicidal and insecticidal preparations, as well as increase the fire resistance of fabrics and non-woven materials based on wool, cotton, linen and silk,» elaborates Fakhrullin.

KFU bionanotechnologists will develop methods for modifying human hair. With their help, it will be possible not only to change the color of the hair, thickness, texture and aroma, but also to protect the structure of the hair and skin under them from ultraviolet radiation.

In addition, using these methods, the project head is convinced, it will be possible to create tools for applying topical anti-inflammatory drugs based on functional nano containers. When applied to human hair in affected areas of the skin, they will provide a prolonged gradual release of drugs. Veterinary preparations with a similar principle of action can be applied to the fur of farm and domestic animals for medicinal purposes.

In the process, scientists will also study the fundamental processes of self-assembly of inorganic nanoparticles on the surface of biological fibers and determine the optimal parameters for the directed modification of the properties of fibrous materials.

"Inorganic nano particles of various origin, biopolymers and their complexes will be used to study the patterns of self-assembly of nanoparticles on the surface of fibers," Fakhrullin concludes.

Credit: 
Kazan Federal University

USDA-ARS scientists find new tool to combat major wheat disease

WASHINGTON, D.C., April 10 - Agricultural Research Service (ARS) scientists and their colleagues have discovered a gene that can be used to develop varieties of wheat that will be more resistant to Fusarium Head Blight (FHB), a disease that is a major threat both overseas and to the nation's $10 billion annual wheat crop.

A paper reporting the discovery and the cloning of the gene, known as Fhb7, was published today in the journal Science. The study was led by scientists at the Shandong Agricultural University in Shandong, China and co-authors include ARS researchers Guihua Bai and Lanfei Zhao in Manhattan, Kansas, and Steven Xu in Fargo, North Dakota.

The discovery is a major advance in addressing a significant threat to the world's wheat supply. FHB, also known as "scab," is caused by a fungal pathogen, Fusarium graminearum, and results in significant losses in the United States, China, Canada, Europe, and many other countries. It also attacks barley and oats.

When the pathogen grows unchecked in infected grains, it releases mycotoxins that can induce vomiting in humans, as well as weight loss in livestock when they refuse to eat the grains.

The prevalence and severity of FHB outbreaks also could potentially be exacerbated by climate change and varying weather conditions, and by an increasing trend toward more corn production and no-till farming, which both may be increasing the prevalence of the pathogen in fields. Growers often must use fungicides to reduce FHB damage.

The researchers found that the gene effectively reduces FHB by detoxifying the mycotoxins secreted by the pathogen. The gene also confers resistance to crown rot, a wheat disease caused by a related pathogen.

The researchers originally identified the gene in Thinopyrum wheatgrass, a wild relative of wheat that has been previously used to develop varieties of wheat with beneficial traits, such as rust resistance and drought tolerance. They cloned the gene and introduced it into seven wheat cultivars with different genetic profiles to study its effects on plants grown under field conditions.

The results showed that the gene not only conferred resistance to scab in the new plants, but it also had no negative effects on yield or other significant traits.

The study sheds new light on the molecular mechanisms that can make wheat, as well as barley and oats, resistant to the pathogen that causes FHB. New varieties of wheat with better FHB resistance using Fhb7 are expected to be available in a few years, the researchers say.

Credit: 
US Department of Agriculture - Agricultural Research Service

PARP inhibitor drugs can be 'tuned' for better killing of tumor cells

PHILADELPHIA--A prospective "PARP inhibitor" drug that has struggled to show effectiveness in clinical trials against cancers can be structurally modified to greatly increase its power to kill tumor cells, researchers from Penn Medicine report this week in Science.

The team also showed that PARP inhibitor compounds can be "tuned" in the opposite way so that they inhibit PARP-1 enzymes without killing cells, thus potentially making this class of drugs more useful for treating heart disease and other non-cancer conditions where inhibiting PARP-1 is the goal.

"We can now use this new understanding of how PARP inhibitors work to design compounds that are better tailored for specific conditions such as cancers vs. heart disease," said senior author Ben Black, PhD, the Eldridge Reeves Johnson Foundation Professor of Biochemistry and Biophysics and co-director of the Penn Center for Genome Integrity at the Perelman School of Medicine at the University of Pennsylvania.

PARP-1 is a DNA-repair enzyme that becomes particularly important for cell survival when other major DNA-repair factors such as BRCA proteins are missing. PARP inhibitors, of which four have been approved so far by the U.S. Food and Drug Administration, are thus considered especially promising as treatments for cancers driven by BRCA gene mutations. Tumor cells driven by BRCA mutations typically lack any BRCA-based DNA-repair capability, and their exposure to a PARP inhibitor further degrades their ability to fix DNA breaks, making the cells much more likely to die. PARP inhibitors have been shown to improve cancer patient outcomes when used alone or in combination with therapies such as chemo and radiation that induce DNA damage.

Despite promising clinical results for several PARP-1 inhibitors, a mystery has surrounded this drug class. All of these compounds bind tightly to the active site of the PARP-1 enzyme and thus all should inhibit the enzyme very effectively--yet only some of these compounds show potency at killing tumor cells, while others don't.

In recent years, scientists have found increasing evidence that PARP inhibitors kill cancer cells not just by inhibiting PARP-1 activity, but also by somehow trapping PARP-1 enzymes on the DNA breaks they are attempting to fix. Keeping PARP-1 enzymes stuck to a cell's DNA effectively kills the cell when it attempts to divide--and cancer cells divide relatively frequently. The idea that PARP inhibitors vary in their abilities to "trap" PARP-1 enzymes on DNA has emerged as a potential explanation for these compounds' variable cancer-killing effects.

In the new study, Black and his team used sophisticated and sensitive techniques to show that PARP inhibitors bind to the PARP-1 enzyme in ways that weaken or strengthen the enzyme's attachment to DNA breaks. These techniques, which include atomic level structural determination and probing the dynamics of the amide protons of the backbone of PARP-1, go beyond what previous research has done to understand how PARP inhibitors actually work. Veliparib, a PARP-1 inhibitor that has puzzled pharmaceutical scientists with its failure in recent clinical trials against breast and lung cancers, turns out to weaken PARP-1's grip on DNA, which in principle makes it easier for a veliparib-treated tumor cell to survive.

The team showed, however, that they could chemically modify veliparib to greatly boost its ability to trap PARP-1 on DNA. This in turn greatly boosted its cancer-cell-killing effects in experiments with different types of cancer cell.

"It was clear that the increased potency of the new compound relative to unmodified veliparib is due to its increased ability to keep PARP-1 bound to DNA breaks," Black said.

The work greatly clarifies the complex interaction between PARP-1 inhibitors and the PARP-1 enzyme, and shows how variations in this interaction correspond to different cell-killing effects. In principle, Black noted, this improved understanding can now be used not only to design more potent anticancer PARP-1 inhibitors, but also to design PARP-1 inhibitors that don't kill cells by trapping PARP-1 on DNA.

The latter could be useful in treating inflammation, heart disease, stroke, and other conditions that have been shown to involve excessive PARP-1 activity, potentially including COVID-19.

Credit: 
University of Pennsylvania School of Medicine

Technique offers path for biomanufacturing medicines during space flights

image: New bacterial growth technique offers path for biomanufacturing pharmaceuticals during space flights.

Image: 
Rensselaer Polytechnic Institute

TROY, N.Y. -- An instrument currently aboard the International Space Station could grow E. coli bacteria in space, opening a new path to bio-manufacturing drugs during long term space flights. Research published today in Nature Microgravity used an Earth-bound simulator of the space station instrument to grow E. coli, demonstrating that it can be nurtured with methods that promise to be more suitable for space travel than existing alternatives.

"If we can get microorganisms to grow well in space, astronauts can use them to make pharmaceuticals on demand. This could be vital for survival on long missions where resupplying is not an option." said Richard Bonocora, senior author and a faculty member in the Department of Biological Sciences at Rensselaer Polytechnic Institute. "Here we were asking: 'Is there a better way to grow microorganisms that what is currently being used is space?' And what we find is that --with shear force-- yes, there likely is."

With promising results, the team hopes to conduct a similar experiment aboard the space station. And while they're starting with E. coli, the workhorse of molecular biology, the team hopes to eventually use the instrument to grow microorganisms with radiation resistance, which could protect developing pharmaceuticals from the ever-present radiation of space as they are produced.

Bacteria like E. coli need oxygen to grow, and the gold standard method for aerating bacteria in a liquid growth medium uses an orbital shaker, a machine that horizontally shakes a platform on which the vessels containing the liquid can be stowed. The shaker relies on the force of gravity to swirl the liquid contents, which rise and fall within a flask, mixing oxygen with the liquid.

But Bonocora and his research team believe an instrument sent to the space station in July, 2019 could do a better job. Inspired by the research of Rensselaer professor Amir Hirsa, the NASA-built instrument uses shearing force, the force created at the boundary of two bodies pushing in opposite directions from one another, similar to that which occurs at the fault lines between tectonic plates. The instrument uses a syringe to dispense a drop of liquid which forms a bubble. One side of the bubble adheres to a stationary ring, while the other side adheres to a thin ring that can rotate. The rotating ring creates shear force on the surface of the bubble, swirling its contents.

Watch a video about how the instrument is being used to research proteins in space.

The shearing instrument is currently being used to carry out Hirsa's experiments studying the effects of shear stress on amyloid fibrils, clusters of proteins that are linked to neurodegenerative disease like diabetes, Alzheimer's, and Parkinson's.

On Earth, Bonocora used a knife-edge viscometer, an instrument designed by Hirsa's group, in which the tip of a metal tube rotates --similar to the rotating ring in the space-based instrument-- at the surface of liquid in a dish to simulate the shearing force. The experiment tested how well bacteria grew when aerated by the knife-edge viscometer and an orbital shaker, with both instruments used at various speeds.

At higher speeds, bacteria aerated by the knife-edge viscometer showed growth rates approaching that of the orbital shaker. Even at lower speeds shear force produced significantly more growth than samples of bacteria that were not mechanically aerated.

"This is a viable way of growing microorganisms. We're starting on a new path, and now we need to think about a more real-life environment, such as on the space station," said Bonocora.

"Space-based pharmaceutical manufacturing is a critical component of our efforts to safely send humans deeper into the solar system. This research is fundamental to that goal," said Curt Breneman, dean of the School of Science. "The successful collaboration between Rick and Amir's teams speaks to our long-standing ties to space exploration, and is one of many examples of the culture of 'low walls' to interdisciplinary research that we are proud to nurture at Rensselaer."

Bonocora and Hirsa were joined by Joe Adams and Shreyash Gulati in this research. "Growth of microorganisms in an interfacially-driven space bioreactor analog" was supported with funding from NASA.

Credit: 
Rensselaer Polytechnic Institute