Category Archives: medicine

Preventing warmed-up vaccines from becoming useless

One of the major problems with vaccines is that they need to be refrigerated. (The Nanopatch, which additionally wouldn’t require needles or syringes, is my favourite proposed solution and it comes from Australia.) This latest research into making vaccines more long-lasting is from the UK and takes a different approach to the problem.

From a June 8, 2020 news item on phys.org,

Vaccines are notoriously difficult to transport to remote or dangerous places, as they spoil when not refrigerated. Formulations are safe between 2°C and 8°C, but at other temperatures the proteins start to unravel, making the vaccines ineffective. As a result, millions of children around the world miss out on life-saving inoculations.

However, scientists have now found a way to prevent warmed-up vaccines from degrading. By encasing protein molecules in a silica shell, the structure remains intact even when heated to 100°C, or stored at room temperature for up to three years.

The technique for tailor-fitting a vaccine with a silica coat—known as ensilication—was developed by a Bath [University] team in collaboration with the University of Newcastle. This pioneering technology was seen to work in the lab two years ago, and now it has demonstrated its effectiveness in the real world too.

Here’s the lead researcher describing her team’s work

Ensilication: success in animal trials from University of Bath on Vimeo.

A June 8, 2020 University of Bath press release (also on EurekAlert) fills in more details about the research,

In their latest study, published in the journal Scientific Reports, the researchers sent both ensilicated and regular samples of the tetanus vaccine from Bath to Newcastle by ordinary post (a journey time of over 300 miles, which by post takes a day or two). When doses of the ensilicated vaccine were subsequently injected into mice, an immune response was triggered, showing the vaccine to be active. No immune response was detected in mice injected with unprotected doses of the vaccine, indicating the medicine had been damaged in transit.

Dr Asel Sartbaeva, who led the project from the University of Bath’s Department of Chemistry, said: “This is really exciting data because it shows us that ensilication preserves not just the structure of the vaccine proteins but also the function – the immunogenicity.”

“This project has focused on tetanus, which is part of the DTP (diphtheria, tetanus and pertussis) vaccine given to young children in three doses. Next, we will be working on developing a thermally-stable vaccine for diphtheria, and then pertussis. Eventually we want to create a silica cage for the whole DTP trivalent vaccine, so that every child in the world can be given DTP without having to rely on cold chain distribution.”

Cold chain distribution requires a vaccine to be refrigerated from the moment of manufacturing to the endpoint destination.

Silica is an inorganic, non-toxic material, and Dr Sartbaeva estimates that ensilicated vaccines could be used for humans within five to 15 years. She hopes the technology to silica-wrap proteins will eventually be adopted to store and transport all childhood vaccines, as well as other protein-based products, such as antibodies and enzymes.

“Ultimately, we want to make important medicines stable so they can be more widely available,” she said. “The aim is to eradicate vaccine-preventable diseases in low income countries by using thermally stable vaccines and cutting out dependence on cold chain.”

Currently, up to 50% of vaccine doses are discarded before use due to exposure to suboptimal temperatures. According to the World Health Organisation (WHO), 19.4 million infants did not receive routine life-saving vaccinations in 2018.

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

Ensilicated tetanus antigen retains immunogenicity: in vivo study and time-resolved SAXS characterization by A. Doekhie, R. Dattani, Y-C. Chen, Y. Yang, A. Smith, A. P. Silve, F. Koumanov, S. A. Wells, K. J. Edler, K. J. Marchbank, J. M. H. van den Elsen & A. Sartbaeva. Scientific Reports volume 10, Article number: 9243 (2020) DOI: https://doi.org/10.1038/s41598-020-65876-3 Published 08 June 2020

This paper is open access

Nanopatch update

I tend to lose track as a science gets closer to commercialization since the science news becomes business news and I almost never scan that sector. It’s been about two-and-half years since I featured research that suggested Nanopatch provided more effective polio vaccination than the standard needle and syringe method in a December 20, 2017 post. The latest bits of news have an interesting timeline.

March 2020

Mark Kendal (Wikipedia entry) is the researcher behind the Nanopatch. He’s interviewed in a March 5, 2020 episode (about 20 mins.) in the Pioneers Series (bankrolled by Rolex [yes, the watch company]) on Monocle.com. Coincidentally or not, a new piece of research funded by Vaxxas (the nanopatch company founded by Mark Kendall; on the website you will find a ‘front’ page and a ‘Contact us’ page only) was announced in a March 17, 2020 news item on medical.net,

Vaxxas, a clinical-stage biotechnology company commercializing a novel vaccination platform, today announced the publication in the journal PLoS Medicine of groundbreaking clinical research indicating the broad immunological and commercial potential of Vaxxas’ novel high-density microarray patch (HD-MAP). Using influenza vaccine, the clinical study of Vaxxas’ HD-MAP demonstrated significantly enhanced immune response compared to vaccination by needle/syringe. This is the largest microarray patch clinical vaccine study ever performed.

“With vaccine coated onto Vaxxas HD-MAPs shown to be stable for up to a year at 40°C [emphasis mine], we can offer a truly differentiated platform with a global reach, particularly into low and middle income countries or in emergency use and pandemic situations,” said Angus Forster, Chief Development and Operations Officer of Vaxxas and lead author of the PLoS Medicine publication. “Vaxxas’ HD-MAP is readily fabricated by injection molding to produce a 10 x 10 mm square with more than 3,000 microprojections that are gamma-irradiated before aseptic dry application of vaccine to the HD-MAP’s tips. All elements of device design, as well as coating and QC, have been engineered to enable small, modular, aseptic lines to make millions of vaccine products per week.”

The PLoS publication reported results and analyses from a clinical study involving 210 clinical subjects [emphasis mine]. The clinical study was a two-part, randomized, partially double-blind, placebo-controlled trial conducted at a single Australian clinical site. The clinical study’s primary objective was to measure the safety and tolerability of A/Singapore/GP1908/2015 H1N1 (A/Sing) monovalent vaccine delivered by Vaxxas HD-MAP in comparison to an uncoated Vaxxas HD-MAP and IM [intramuscular] injection of a quadrivalent seasonal influenza vaccine (QIV) delivering approximately the same dose of A/Sing HA protein. Exploratory outcomes were: to evaluate the immune responses to HD-MAP application to the forearm with A/Sing at 4 dose levels in comparison to IM administration of A/Sing at the standard 15 μg HA per dose per strain, and to assess further measures of immune response through additional assays and assessment of the local skin response via punch biopsy of the HD-MAP application sites. Local skin response, serological, mucosal and cellular immune responses were assessed pre- and post-vaccination.

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

Safety, tolerability, and immunogenicity of influenza vaccination with a high-density microarray patch: Results from a randomized, controlled phase I clinical trial by Angus H. Forster, Katey Witham, Alexandra C. I. Depelsenaire, Margaret Veitch, James W. Wells, Adam Wheatley, Melinda Pryor, Jason D. Lickliter, Barbara Francis, Steve Rockman, Jesse Bodle, Peter Treasure, Julian Hickling, Germain J. P. Fernando. DOI: https://doi.org/10.1371/journal.pmed.1003024 PLOS (Public Library of Science) Published: March 17, 2020

This is an open access paper.

May 2020

Two months later, Merck, an American multinational pharmaceutical company, showed some serious interest in the ‘nanopatch’. A May 28, 2020 article by Chris Newmarker for drugdelvierybusiness.com announces the news (Note: Links have been removed),

Merck has exercised its option to use Vaxxas‘ High Density Microarray Patch (HD-MAP) platform as a delivery platform for a vaccine candidate, the companies announced today [Thursday, May 28, 2020].

Also today, Vaxxas announced that German manufacturing equipment maker Harro Höfliger will help Vaxxas develop a high-throughput, aseptic manufacturing line to make vaccine products based on Vaxxas’ HD-MAP technology. Initial efforts will focus on having a pilot line operating in 2021 to support late-stage clinical studies — with a goal of single, aseptic-based lines being able to churn out 5 million vaccine products a week.

“A major challenge in commercializing microarray patches — like Vaxxas’ HD-MAP — for vaccination is the ability to manufacture at industrially-relevant scale, while meeting stringent sterility and quality standards. Our novel device design along with our innovative vaccine coating and quality verification technologies are an excellent fit for integration with Harro Höfliger’s aseptic process automation platforms. Adopting a modular approach, it will be possible to achieve output of tens-of-millions of vaccine-HD-MAP products per week,” Hoey [David L. Hoey, President and CEO of Vaxxas] said.

Vaxxas also claims that the patches can deliver vaccine more efficiently — a positive when people around the world are clamoring for a vaccine against COVID-19. The company points to a recent [March 17, 2020] clinical study in which their micropatch delivering a sixth of an influenza vaccine dose produced an immune response comparable to a full dose by intramuscular injection. A two-thirds dose by HD-MAP generated significantly faster and higher overall antibody responses.

As I noted earlier, this is an interesting timeline.

Final comment

In the end, what all of this means is that there may be more than one way to deal with vaccines and medicines that deteriorate all too quickly unless refrigerated. I wish all of these researchers the best.

Antiviral, antibacterial surface for reducing spread of infectious diseases

In the past several years, scientists have created antibacterial surfaces by fabricating materials with specific types of nanostructures. According to a May 27, 2020 news item on Nanowerk, scientists have now been able to add antiviral properties (Note: A link has been removed),

The novel coronavirus pandemic has caused an increased demand for antimicrobial treatments that can keep surfaces clean, particularly in health care settings. Although some surfaces have been developed that can combat bacteria, what’s been lacking is a surface that can also kill off viruses.

Now, researchers have found a way to impart durable antiviral and antibacterial properties to an aluminum alloy used in hospitals, according to a report in ACS Biomaterials Science & Engineering (“Antiviral and Antibacterial Nanostructured Surfaces with Excellent Mechanical Properties for Hospital Applications”).

A May 27, 2020 American Chemical Society (ACS) news release (also on EurekAlert), which originated the news item, describes the problem and the proposed solution,

Among other mechanisms, viruses and bacteria can spread when a person touches a site where germs have settled, such as a doorframe, handrail or medical device. A healthy person can often fight off these bugs, but hospital patients can be more vulnerable to infection. The number of hospital-acquired infections has been on the decline in the U.S., but they still cause tens of thousands of deaths every year, according to the U.S. Department of Health and Human Services. Chemical disinfectants or coatings containing hydrophobic compounds, silver ions or copper can reduce infectious contaminants on surfaces, but these treatments don’t last. However, nature has developed its own solutions for battling microorganisms, including microscopic structural features that render some insect wings lethal to bacteria. Scientists have replicated this effect by forming surfaces covered with minute pillars and other shapes that distort and kill bacterial cells. But Prasad Yarlagadda and colleagues wanted to inactivate viruses as well as bacteria, so they set out to generate a novel nanoscale topography on long-lasting, industrially relevant materials.

The team experimented with disks of aluminum 6063, which is used in doorframes, window panels, and hospital and medical equipment. Etching the disks with sodium hydroxide for up to 3 hours changed the initially smooth, hydrophobic surface into a ridged, hydrophilic surface. Bacteria or viruses were then applied to the etched disks. Most of the Pseudomonas aeruginosa and Staphylococcus aureus bacteria were inactivated after 3 hours on the surface, while viability of common respiratory viruses dropped within 2 hours; both results were better than with plastic or smooth aluminum surfaces. The disks retained their effectiveness even after tests designed to mimic hospital wear and tear. The researchers note this is the first report to show combined antibacterial and antiviral properties of a durable, nanostructured surface that has the potential to stop the spread of infections arising from physical surfaces in hospitals. This strategy could be extended to surfaces in other public areas, such as cruise ships, planes and airports, they say. The team is now studying the effects of their nano-textured aluminum surfaces on the novel coronavirus.

This approach reminds me of Sharklet, a company fabricating a material designed to mimic a shark’s skin which is naturally antibacterial due to the nanostructures on its skin (see my September 18, 2014 posting).

More about Sharklet later. First, here’s a link to and a citation for the paper about this latest work,

Antiviral and Antibacterial Nanostructured Surfaces with Excellent Mechanical Properties for Hospital Applications by Jafar Hasan, Yanan Xu, Tejasri Yarlagadda, Michael Schuetz, Kirsten Spann, and Prasad KDV Yarlagadda. ACS Biomater. Sci. Eng. 2020, XXXX, XXX, XXX-XXX DOI: https://doi.org/10.1021/acsbiomaterials.0c00348 Publication Date:May 7, 2020 Copyright © 2020 American Chemical Society

This paper is behind a paywall.

Business and science: a Sharklet update

You can find the Sharklet website here. I wasn’t able to find any news about recent business deals other than the company’s acquisition by Peaceful Union in May 2017. From a May 17, 2017 Sharklet news release on Business Wire (and on the company website here),

Sharklet Technologies, Inc., a biotechnology company lauded for the creation and commercialization of Sharklet®, the world’s first micro-texture that inhibits bacterial growth on surfaces, has announced that it has completed a financing event led by Peaceful Union, an equity medical device firm in Hangzhou, China. Terms of the transaction were not disclosed.

The acquisition of the company will enable Sharklet Technologies to accelerate the development of Sharklet for medical devices where chemical-free bacterial inhibition is desired as well as high-touch surfaces prone to bacterial contamination. The company also will accelerate development of a newly enhanced wound dressing technology to encourage healing.

Joe Bagan and Mark Spiecker led the transaction structure. “This is an important day for the company and investors,” said Joe Bagan, former board chair, and Mark Spiecker, former CEO. “Our investors will realize a significant transaction while enabling the company to accelerate growth.”

In concert with the investment, Sharklet Technologies founding member, chief technology officer, and Sharklet inventor Dr. Anthony Brennan, will become chairman of the board assuming duties from chairman Joe Bagan and CEO Mark Spiecker.

Interestingly, Bagan and Spiecker are Chief Executive Officer (CEO) and President, respectively at STAQ Pharma. I wonder if there are plans to sell this company too.

Getting back to Sharklet, I found two items of recent origin about business but I cannot speak to the accuracy or trustworthiness of either item. That said, you will find they provide some detail about Sharklet’s new business directions and new business ties.

While Sharklet’s current business associations have a sketchy quality, it seems that’s not unusual in business, especially where new technologies are concerned. For example, the introduction of electricity into homes and businesses was a tumultuous affair as the 2008 book, ‘Power Struggles; Scientific Authority and the Creation of Practical Electricity Before Edison’ by Michael Brian Schiffer makes clear, from the MIT [Massachusetts Institute of Technology] Press ‘Power Struggles’ webpage,

In 1882, Thomas Edison and his Edison Electric Light Company unveiled the first large-scale electrical system in the world to light a stretch of offices in a city. … After laying out a unified theoretical framework for understanding technological change, Schiffer presents a series of fascinating case studies of pre-Edison electrical technologies, including Volta’s electrochemical battery, the blacksmith’s electric motor, the first mechanical generators, Morse’s telegraph, the Atlantic cable, and the lighting of the Capitol dome. Schiffer discusses claims of “practicality” and “impracticality” (sometimes hotly contested) made for these technologies, and examines the central role of the scientific authority—in particular, the activities of Joseph Henry, mid-nineteenth-century America’s foremost scientist—in determining the fate of particular technologies. These emerging electrical technologies formed the foundation of the modern industrial world. Schiffer shows how and why they became commercial products in the context of an evolving corporate capitalism in which conflicting judgments of practicality sometimes turned into power struggles. [emphases mine]

Even given that the book’s focus is pre-Edison electricity, how do you mention Edison himself without even casually mentioning Nikola Tesla and George Westinghouse in the book’s overview? Getting back to my point, emerging technologies do not emerge easily.

Tiny sponges lure coronavirus away from lung cells

This research approach looks promising as three news releases trumpeting the possibilities indicate. First, there’s the June 17, 2020 American Chemical Society (ACS) news release,

Scientists are working overtime to find an effective treatment for COVID-19, the illness caused by the new coronavirus, SARS-CoV-2. Many of these efforts target a specific part of the virus, such as the spike protein. Now, researchers reporting in Nano Letters have taken a different approach, using nanosponges coated with human cell membranes –– the natural targets of the virus –– to soak up SARS-CoV-2 and keep it from infecting cells in a petri dish.

To gain entry, SARS-CoV-2 uses its spike protein to bind to two known proteins on human cells, called ACE2 and CD147. Blocking these interactions would keep the virus from infecting cells, so many researchers are trying to identify drugs directed against the spike protein. Anthony Griffiths, Liangfang Zhang and colleagues had a different idea: making a nanoparticle decoy with the virus’ natural targets, including ACE2 and CD147, to lure SARS-CoV-2 away from cells. And to test this idea, they conducted experiments with the actual SARS-CoV-2 virus in a biosafety level 4 lab.

The researchers coated a nanoparticle polymer core with cell membranes from either human lung epithelial cells or macrophages –– two cell types infected by SARS-CoV-2. They showed that the nanosponges had ACE2 and CD147, as well as other cell membrane proteins, projecting outward from the polymer core. When administered to mice, the nanosponges did not show any short-term toxicity. Then, the researchers treated cells in a dish with SARS-CoV-2 and the lung epithelial or macrophage nanosponges. Both decoys neutralized SARS-CoV-2 and prevented it from infecting cells to a similar extent. The researchers plan to next test the nanosponges in animals before moving to human clinical trials. In theory, the nanosponge approach would work even if SARS-CoV-2 mutates to resist other therapies, and it could be used against other viruses, as well, the researchers say.

In this illustration, a nanosponge coated with a human cell membrane acts as a decoy to prevent a virus from entering cells. Credit: Adapted from Nano Letters 2020, DOI: 10.1021/acs.nanolett.0c02278

There are two research teams involved, one at Boston University and the other at the University of California at San Diego (UC San Diego or UCSD). The June 18, 2020 Boston University news release (also on EurekAlert) by Kat J. McAlpine adds more details about the research, provides some insights from the researchers, and is a little redundant if you’ve already seen the ACS news release,

Imagine if scientists could stop the coronavirus infection in its tracks simply by diverting its attention away from living lung cells? A new therapeutic countermeasure, announced in a Nano Letters study by researchers from Boston University’s National Emerging Infectious Diseases Laboratories (NEIDL) and the University of California San Diego, appears to do just that in experiments that were carried out at the NEIDL in Boston.

The breakthrough technology could have major implications for fighting the SARS-CoV-2 virus responsible for the global pandemic that’s already claimed nearly 450,000 lives and infected more than 8 million people. But, perhaps even more significantly, it has the potential to be adapted to combat virtually any virus, such as influenza or even Ebola.

“I was skeptical at the beginning because it seemed too good to be true,” says NEIDL microbiologist Anna Honko, one of the co-first authors on the study. “But when I saw the first set of results in the lab, I was just astonished.”

The technology consists of very small, nanosized drops of polymers–essentially, soft biofriendly plastics–covered in fragments of living lung cell and immune cell membranes.

“It looks like a nanoparticle coated in pieces of cell membrane,” Honko says. “The small polymer [droplet] mimics a cell having a membrane around it.”

The SARS-CoV-2 virus seeks out unique signatures of lung cell membranes and latches onto them. When that happens inside the human body, the coronavirus infection takes hold, with the SARS-CoV-2 viruses hijacking lung cells to replicate their own genetic material. But in experiments at the NEIDL, BU researchers observed that polymer droplets laden with pieces of lung cell membrane did a better job of attracting the SARS-CoV-2 virus than living lung cells. [emphasis mine]

By fusing with the SARS-CoV-2 virus better than living cells can, the nanotechnology appears to be an effective countermeasure to coronavirus infection, preventing SARS-CoV-2 from attacking cells.

“Our guess is that it acts like a decoy, it competes with cells for the virus,” says NEIDL microbiologist Anthony Griffiths, co-corresponding author on the study. “They are little bits of plastic, just containing the outer pieces of cells with none of the internal cellular machinery contained inside living cells. Conceptually, it’s such a simple idea. It mops up the virus like a sponge.”

That attribute is why the UC San Diego and BU research team call the technology “nanosponges.” Once SARS-CoV-2 binds with the cell fragments inside a nanosponge droplet–each one a thousand times smaller than the width of a human hair–the coronavirus dies. Although the initial results are based on experiments conducted in cell culture dishes, the researchers believe that inside a human body, the biodegradable nanosponges and the SARS-CoV-2 virus trapped inside them could then be disposed of by the body’s immune system. The immune system routinely breaks down and gets rid of dead cell fragments caused by infection or normal cell life cycles.

There is also another important effect that the nanosponges have in the context of coronavirus infection. Honko says nanosponges containing fragments of immune cells can soak up cellular signals that increase inflammation [emphases mine]. Acute respiratory distress, caused by an inflammatory cascade inside the lungs, is the most deadly aspect of the coronavirus infection, sending patients into the intensive care unit for oxygen or ventilator support to help them breathe.

But the nanosponges, which can attract the inflammatory molecules that send the immune system into dangerous overdrive, can help tamp down that response, Honko says. By using both kinds of nanosponges, some containing lung cell fragments and some containing pieces of immune cells, she says it’s possible to “attack the coronavirus and the [body’s] response” responsible for disease and eventual lung failure.

At the NEIDL, Honko and Griffiths are now planning additional experiments to see how well the nanosponges can prevent coronavirus infection in animal models of the disease. They plan to work closely with the team of engineers at UC San Diego, who first developed the nanosponges more than a decade ago, to tailor the technology for eventual safe and effective use in humans.

“Traditionally, drug developers for infectious diseases dive deep on the details of the pathogen in order to find druggable targets,” said Liangfang Zhang, a UC San Diego nanoengineer and leader of the California-based team, according to a UC San Diego press release. “Our approach is different. We only need to know what the target cells are. And then we aim to protect the targets by creating biomimetic decoys.”

When the novel coronavirus first appeared, the idea of using the nanosponges to combat the infection came to Zhang almost immediately. He reached out to the NEIDL for help. Looking ahead, the BU and UC San Diego collaborators believe the nanosponges can easily be converted into a noninvasive treatment.

“We should be able to drop it right into the nose,” Griffiths says. “In humans, it could be something like a nasal spray.”

Honko agrees: “That would be an easy and safe administration method that should target the appropriate [respiratory] tissues. And if you wanted to treat patients that are already intubated, you could deliver it straight into the lung.”

Griffiths and Honko are especially intrigued by the nanosponges as a new platform for treating all types of viral infections. “The broad spectrum aspect of this is exceptionally appealing,” Griffiths says. The researchers say the nanosponge could be easily adapted to house other types of cell membranes preferred by other viruses, creating many new opportunities to use the technology against other tough-to-treat infections like the flu and even deadly hemorrhagic fevers caused by Ebola, Marburg, or Lassa viruses.

“I’m interested in seeing how far we can push this technology,” Honko says.

The University of California as San Diego has released a video illustrating the nanosponges work,

There’s also this June 17, 2020 University of California at San Diego (UC San Diego) news release (also on EurekAlert) by Ioana Patringenaru, which offers extensive new detail along with, if you’ve read one or both of the news releases in the above, a few redundant bits,

Nanoparticles cloaked in human lung cell membranes and human immune cell membranes can attract and neutralize the SARS-CoV-2 virus in cell culture, causing the virus to lose its ability to hijack host cells and reproduce.

The first data describing this new direction for fighting COVID-19 were published on June 17 in the journal Nano Letters. The “nanosponges” were developed by engineers at the University of California San Diego and tested by researchers at Boston University.

The UC San Diego researchers call their nano-scale particles “nanosponges” because they soak up harmful pathogens and toxins.

In lab experiments, both the lung cell and immune cell types of nanosponges caused the SARS-CoV-2 virus to lose nearly 90% of its “viral infectivity” in a dose-dependent manner. Viral infectivity is a measure of the ability of the virus to enter the host cell and exploit its resources to replicate and produce additional infectious viral particles.

Instead of targeting the virus itself, these nanosponges are designed to protect the healthy cells the virus invades.

“Traditionally, drug developers for infectious diseases dive deep on the details of the pathogen in order to find druggable targets. Our approach is different. We only need to know what the target cells are. And then we aim to protect the targets by creating biomimetic decoys,” said Liangfang Zhang, a nanoengineering professor at the UC San Diego Jacobs School of Engineering.

His lab first created this biomimetic nanosponge platform more than a decade ago and has been developing it for a wide range of applications ever since [emphasis mine]. When the novel coronavirus appeared, the idea of using the nanosponge platform to fight it came to Zhang “almost immediately,” he said.

In addition to the encouraging data on neutralizing the virus in cell culture, the researchers note that nanosponges cloaked with fragments of the outer membranes of macrophages could have an added benefit: soaking up inflammatory cytokine proteins, which are implicated in some of the most dangerous aspects of COVID-19 and are driven by immune response to the infection.

Making and testing COVID-19 nanosponges

Each COVID-19 nanosponge–a thousand times smaller than the width of a human hair–consists of a polymer core coated in cell membranes extracted from either lung epithelial type II cells or macrophage cells. The membranes cover the sponges with all the same protein receptors as the cells they impersonate–and this inherently includes whatever receptors SARS-CoV-2 uses to enter cells in the body.

The researchers prepared several different concentrations of nanosponges in solution to test against the novel coronavirus. To test the ability of the nanosponges to block SARS-CoV-2 infectivity, the UC San Diego researchers turned to a team at Boston University’s National Emerging Infectious Diseases Laboratories (NEIDL) to perform independent tests. In this BSL-4 lab–the highest biosafety level for a research facility–the researchers, led by Anthony Griffiths, associate professor of microbiology at Boston University School of Medicine, tested the ability of various concentrations of each nanosponge type to reduce the infectivity of live SARS-CoV-2 virus–the same strains that are being tested in other COVID-19 therapeutic and vaccine research.

At a concentration of 5 milligrams per milliliter, the lung cell membrane-cloaked sponges inhibited 93% of the viral infectivity of SARS-CoV-2. The macrophage-cloaked sponges inhibited 88% of the viral infectivity of SARS-CoV-2. Viral infectivity is a measure of the ability of the virus to enter the host cell and exploit its resources to replicate and produce additional infectious viral particles.

“From the perspective of an immunologist and virologist, the nanosponge platform was immediately appealing as a potential antiviral because of its ability to work against viruses of any kind. This means that as opposed to a drug or antibody that might very specifically block SARS-CoV-2 infection or replication, these cell membrane nanosponges might function in a more holistic manner in treating a broad spectrum of viral infectious diseases. I was optimistically skeptical initially that it would work, and then thrilled once I saw the results and it sunk in what this could mean for therapeutic development as a whole,” said Anna Honko, a co-first author on the paper and a Research Associate Professor, Microbiology at Boston University’s National Emerging Infectious Diseases Laboratories (NEIDL).

In the next few months, the UC San Diego researchers and collaborators will evaluate the nanosponges’ efficacy in animal models. The UC San Diego team has already shown short-term safety in the respiratory tracts and lungs of mice. If and when these COVID-19 nanosponges will be tested in humans depends on a variety of factors, but the researchers are moving as fast as possible.

“Another interesting aspect of our approach is that even as SARS-CoV-2 mutates, as long as the virus can still invade the cells we are mimicking, our nanosponge approach should still work. I’m not sure this can be said for some of the vaccines and therapeutics that are currently being developed,” said Zhang.

The researchers also expect these nanosponges would work against any new coronavirus or even other respiratory viruses, including whatever virus might trigger the next respiratory pandemic.

Mimicking lung epithelial cells and immune cells

Since the novel coronavirus often infects lung epithelial cells as the first step in COVID-19 infection, Zhang and his colleagues reasoned that it would make sense to cloak a nanoparticle in fragments of the outer membranes of lung epithelial cells to see if the virus could be tricked into latching on it instead of a lung cell.

Macrophages, which are white blood cells that play a major role in inflammation, also are very active in the lung during the course of a COVID-19 illness, so Zhang and colleagues created a second sponge cloaked in macrophage membrane.

The research team plans to study whether the macrophage sponges also have the ability to quiet cytokine storms in COVID-19 patients.

“We will see if the macrophage nanosponges can neutralize the excessive amount of these cytokines as well as neutralize the virus,” said Zhang.

Using macrophage cell fragments as cloaks builds on years of work to develop therapies for sepsis using macrophage nanosponges.

In a paper published in 2017 in Proceedings of the National Academy of Sciences, Zhang and a team of researchers at UC San Diego showed that macrophage nanosponges can safely neutralize both endotoxins and pro-inflammatory cytokines in the bloodstream of mice. A San Diego biotechnology company co-founded by Zhang called Cellics Therapeutics is working to translate this macrophage nanosponge work into the clinic.

A potential COVID-19 therapeutic The COVID-19 nanosponge platform has significant testing ahead of it before scientists know whether it would be a safe and effective therapy against the virus in humans, Zhang cautioned [emphasis mine]. But if the sponges reach the clinical trial stage, there are multiple potential ways of delivering the therapy that include direct delivery into the lung for intubated patients, via an inhaler like for asthmatic patients, or intravenously, especially to treat the complication of cytokine storm.

A therapeutic dose of nanosponges might flood the lung with a trillion or more tiny nanosponges that could draw the virus away from healthy cells. Once the virus binds with a sponge, “it loses its viability and is not infective anymore, and will be taken up by our own immune cells and digested,” said Zhang.

“I see potential for a preventive treatment, for a therapeutic that could be given early because once the nanosponges get in the lung, they can stay in the lung for some time,” Zhang said. “If a virus comes, it could be blocked if there are nanosponges waiting for it.”

Growing momentum for nanosponges

Zhang’s lab at UC San Diego created the first membrane-cloaked nanoparticles over a decade ago. The first of these nanosponges were cloaked with fragments of red blood cell membranes. These nanosponges are being developed to treat bacterial pneumonia and have undergone all stages of pre-clinical testing by Cellics Therapeutics, the San Diego startup cofounded by Zhang. The company is currently in the process of submitting the investigational new drug (IND) application to the FDA for their lead candidate: red blood cell nanosponges for the treatment of methicillin-resistant staphylococcus aureus (MRSA) pneumonia. The company estimates the first patients in a clinical trial will be dosed next year.

The UC San Diego researchers have also shown that nanosponges can deliver drugs to a wound site; sop up bacterial toxins that trigger sepsis; and intercept HIV before it can infect human T cells.

The basic construction for each of these nanosponges is the same: a biodegradable, FDA-approved polymer core is coated in a specific type of cell membrane, so that it might be disguised as a red blood cell, or an immune T cell or a platelet cell. The cloaking keeps the immune system from spotting and attacking the particles as dangerous invaders.

“I think of the cell membrane fragments as the active ingredients. This is a different way of looking at drug development,” said Zhang. “For COVID-19, I hope other teams come up with safe and effective therapies and vaccines as soon as possible. At the same time, we are working and planning as if the world is counting on us.”

I wish the researchers good luck. For the curious, here’s a link to and a citation for the paper,

Cellular Nanosponges Inhibit SARS-CoV-2 Infectivity by Qiangzhe Zhang, Anna Honko, Jiarong Zhou, Hua Gong, Sierra N. Downs, Jhonatan Henao Vasquez, Ronnie H. Fang, Weiwei Gao, Anthony Griffiths, and Liangfang Zhang. Nano Lett. 2020, XXXX, XXX, XXX-XXX DOI: https://doi.org/10.1021/acs.nanolett.0c02278 Publication Date:June 17, 2020 Copyright © 2020 American Chemical Society

This paper appears to be open access.

Here, too, is the Cellics Therapeutics website.

Brain scan variations

The Scientist is a magazine I do not feature here often enough. The latest issue (June 2020) features a May 20, 2020 opinion piece by Ruth Williams on a recent study about interpretating brain scans—70 different teams of neuroimaging experts were involved (Note: Links have been removed),

In a test of scientific reproducibility, multiple teams of neuroimaging experts from across the globe were asked to independently analyze and interpret the same functional magnetic resonance imaging dataset. The results of the test, published in Nature today (May 20), show that each team performed the analysis in a subtly different manner and that their conclusions varied as a result. While highlighting the cause of the irreproducibility—human methodological decisions—the paper also reveals ways to safeguard future studies against it.

Problems with reproducibility plague all areas of science, and have been particularly highlighted in the fields of psychology and cancer through projects run in part by the Center for Open Science. Now, neuroimaging has come under the spotlight thanks to a collaborative project by neuroimaging experts around the world called the Neuroimaging Analysis Replication and Prediction Study (NARPS).

Neuroimaging, specifically functional magnetic resonance imaging (fMRI), which produces pictures of blood flow patterns in the brain that are thought to relate to neuronal activity, has been criticized in the past for problems such as poor study design and statistical methods, and specifying hypotheses after results are known (SHARKing), says neurologist Alain Dagher of McGill University who was not involved in the study. A particularly memorable criticism of the technique was a paper demonstrating that, without needed statistical corrections, it could identify apparent brain activity in a dead fish.

Perhaps because of such criticisms, nowadays fMRI “is a field that is known to have a lot of cautiousness about statistics and . . . about the sample sizes,” says neuroscientist Tom Schonberg of Tel Aviv University, an author of the paper and co-coordinator of NARPS. Also, unlike in many areas of biology, he adds, the image analysis is computational, not manual, so fewer biases might be expected to creep in.

Schonberg was therefore a little surprised to see the NARPS results, admitting, “it wasn’t easy seeing this variability, but it was what it was.”

The study, led by Schonberg together with psychologist Russell Poldrack of Stanford University and neuroimaging statistician Thomas Nichols of the University of Oxford, recruited independent teams of researchers around the globe to analyze and interpret the same raw neuroimaging data—brain scans of 108 healthy adults taken while the subjects were at rest and while they performed a simple decision-making task about whether to gamble a sum of money.

Each of the 70 research teams taking part used one of three different image analysis software packages. But variations in the final results didn’t depend on these software choices, says Nichols. Instead, they came down to numerous steps in the analysis that each require a human’s decision, such as how to correct for motion of the subjects’ heads, how signal-to-noise ratios are enhanced, how much image smoothing to apply—that is, how strictly the anatomical regions of the brain are defined—and which statistical approaches and thresholds to use.

If this topic interests you, I strongly suggest you read Williams’ article in its entirety.

Here are two links to the paper,

Variability in the analysis of a single neuroimaging dataset by many teams. Nature DOI: https://doi.org/10.1038/s41586-020-2314-9 Published online: 20 May 2020 Check for updates

This first one seems to be a free version of the paper.

Variability in the analysis of a single neuroimaging dataset by many teams by R. Botvinik-Nezer, F. Holzmeister, C. F. Camerer, et al. (at least 70 authors in total) Nature 582, 84–88 (2020). DOI: https://doi.org/10.1038/s41586-020-2314-9 Published 20 May 2020 Issue Date 04 June 2020

This version is behind a paywall.

Gold nanoparticles could help detect the presence of COVID-19 in ten minutes

If this works out, it would make testing for COVID-19 an infinitely easier task. From a May 29, 2020 news item on phys.org,

Scientists from the University of Maryland School of Medicine (UMSOM) developed an experimental diagnostic test for COVID-19 that can visually detect the presence of the virus in 10 minutes. It uses a simple assay containing plasmonic gold nanoparticles to detect a color change when the virus is present. The test does not require the use of any advanced laboratory techniques, such as those commonly used to amplify DNA, for analysis. The authors published their work last week [May 21, 2020] in the American Chemical Society’s nanotechnology journal ACS Nano.

“Based on our preliminary results, we believe this promising new test may detect RNA [ribonucleic acid] material from the virus as early as the first day of infection. Additional studies are needed, however, to confirm whether this is indeed the case,” said study leader Dipanjan Pan, PhD, Professor of Diagnostic Radiology and Nuclear Medicine and Pediatrics at the UMSOM.

Caption: A nasal swab containing a test sample is mixed with a simple lab test. It contains a liquid mixed with gold nanoparticles attached to a molecule that binds to the novel coronavirus. If the virus is present, the gold nanoparticles turns the solution a deep blue color (bottom of the tube) and a precipitation is noticed. If it is not present, the solution retains its original purple color. Credit: University of Maryland School of Medicine

A May 28, 2020 University of Maryland news release (also on EurekAlert), which originated the news item, provides more detail,

Once a nasal swab or saliva sample is obtained from a patient, the RNA is extracted from the sample via a simple process that takes about 10 minutes. The test uses a highly specific molecule attached to the gold nanoparticles to detect a particular protein. This protein is part of the genetic sequence that is unique to the novel coronavirus. When the biosensor binds to the virus’s gene sequence, the gold nanoparticles respond by turning the liquid reagent from purple to blue.

“The accuracy of any COVID-19 test is based on being able to reliably detect any virus. This means it does not give a false negative result if the virus actually is present, nor a false positive result if the virus is not present,” said Dr. Pan. “Many of the diagnostic tests currently on the market cannot detect the virus until several days after infection. For this reason, they have a significant rate of false negative results.”

Dr. Pan created a company called VitruVian Bio to develop the test for commercial application. He plans to have a pre-submission meeting with the U.S. Food and Drug Administration (FDA) within the next month to discuss requirements for getting an emergency use authorization for the test. New FDA policy allows for the marketing of COVID-19 tests without requiring them to go through the usual approval or clearance process. These tests do, however, need to meet certain validation testing requirements to ensure that they provide reliable results.

“This RNA-based test appears to be very promising in terms of detecting the virus. The innovative approach provides results without the need for a sophisticated laboratory facility,” said study co-author Matthew Frieman, PhD, Associate Professor of Microbiology and Immunology at UMSOM.

Although more clinical studies are warranted, this test could be far less expensive to produce and process than a standard COVID-19 lab test; it does not require laboratory equipment or trained personnel to run the test and analyze the results. If this new test meets FDA expectations, it could potentially be used in daycare centers, nursing homes, college campuses, and work places as a surveillance technique to monitor any resurgence of infections.

In Dr. Pan’s laboratory, research scientist Parikshit Moitra, PhD, and UMSOM research fellow Maha Alafeef conducted the studies along with research fellow Ketan Dighe from UMBC.

Dr. Pan holds a joint appointment with the College of Engineering at the University of Maryland Baltimore County and is also a faculty member of the Center for Blood Oxygen Transport and Hemostasis (CBOTH).

“This is another example of how our faculty is driving innovation to fulfill a vital need to expand the capacity of COVID-19 testing,” said Dean E. Albert Reece, MD, PhD, MBA, who is also Executive Vice President for Medical Affairs, UM Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor, University of Maryland School of Medicine. “Our nation will be relying on inexpensive, rapid tests that can be dispersed widely and used often until we have effective vaccines against this pandemic.”

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

Selective Naked-Eye Detection of SARS-CoV-2 Mediated by N Gene Targeted Antisense Oligonucleotide Capped Plasmonic Nanoparticles by Parikshit Moitra, Maha Alafeef, Ketan Dighe, Matthew B. Frieman, and Dipanjan Pan. ACS Nano 2020, XXXX, XXX, XXX-XXX DOI: https://doi.org/10.1021/acsnano.0c03822 Publication Date:May 21, 2020 Copyright © 2020 American Chemical Society

This paper appears to be open access.

I tried to find Dr. Pan’s company, VitruVian Bio and found a business with an almost identical name, Vitruvian Biomedical, which does not include Dr. Pan on its management team list and this company’s focus is on Alzheimer’s Disease. Finally, there is no mention of the COVID-19 test anywhere on the Vitruvian Biomedical website.

Nanodevices show (from the inside) how cells change

Embryo cells + nanodevices from University of Bath on Vimeo.

Caption: Five mouse embryos, each containing a nanodevice that is 22-millionths of a metre long. The film begins when the embryos are 2-hours old and continues for 5 hours. Each embryo is about 100-millionths of a metre in diameter. Credit: Professor Tony Perry

Fascinating, yes? As I often watch before reading the caption, these were mysterious grey blobs moving around was my first impression. Given the headline for the May 26, 2020 news item on ScienceDaily, I was expecting the squarish-shaped devices inside,

For the first time, scientists have introduced minuscule tracking devices directly into the interior of mammalian cells, giving an unprecedented peek into the processes that govern the beginning of development.

This work on one-cell embryos is set to shift our understanding of the mechanisms that underpin cellular behaviour in general, and may ultimately provide insights into what goes wrong in ageing and disease.

The research, led by Professor Tony Perry from the Department of Biology and Biochemistry at the University of Bath [UK], involved injecting a silicon-based nanodevice together with sperm into the egg cell of a mouse. The result was a healthy, fertilised egg containing a tracking device.

This image looks to have been enhanced with colour,

Fluorescence of an embryo containing a nanodevice. Courtesy: University of Bath

A May 25, 2020 University of Bath press release (also on EurekAlert but published May 26, 2020)

The tiny devices are a little like spiders, complete with eight highly flexible ‘legs’. The legs measure the ‘pulling and pushing’ forces exerted in the cell interior to a very high level of precision, thereby revealing the cellular forces at play and showing how intracellular matter rearranged itself over time.

The nanodevices are incredibly thin – similar to some of the cell’s structural components, and measuring 22 nanometres, making them approximately 100,000 times thinner than a pound coin. This means they have the flexibility to register the movement of the cell’s cytoplasm as the one-cell embryo embarks on its voyage towards becoming a two-cell embryo.

“This is the first glimpse of the physics of any cell on this scale from within,” said Professor Perry. “It’s the first time anyone has seen from the inside how cell material moves around and organises itself.”

WHY PROBE A CELL’S MECHANICAL BEHAVIOUR?

The activity within a cell determines how that cell functions, explains Professor Perry. “The behaviour of intracellular matter is probably as influential to cell behaviour as gene expression,” he said. Until now, however, this complex dance of cellular material has remained largely unstudied. As a result, scientists have been able to identify the elements that make up a cell, but not how the cell interior behaves as a whole.

“From studies in biology and embryology, we know about certain molecules and cellular phenomena, and we have woven this information into a reductionist narrative of how things work, but now this narrative is changing,” said Professor Perry. The narrative was written largely by biologists, who brought with them the questions and tools of biology. What was missing was physics. Physics asks about the forces driving a cell’s behaviour, and provides a top-down approach to finding the answer.

“We can now look at the cell as a whole, not just the nuts and bolts that make it.”

Mouse embryos were chosen for the study because of their relatively large size (they measure 100 microns, or 100-millionths of a metre, in diameter, compared to a regular cell which is only 10 microns [10-millionths of a metre] in diameter). This meant that inside each embryo, there was space for a tracking device.

The researchers made their measurements by examining video recordings taken through a microscope as the embryo developed. “Sometimes the devices were pitched and twisted by forces that were even greater than those inside muscle cells,” said Professor Perry. “At other times, the devices moved very little, showing the cell interior had become calm. There was nothing random about these processes – from the moment you have a one-cell embryo, everything is done in a predictable way. The physics is programmed.”

The results add to an emerging picture of biology that suggests material inside a living cell is not static, but instead changes its properties in a pre-ordained way as the cell performs its function or responds to the environment. The work may one day have implications for our understanding of how cells age or stop working as they should, which is what happens in disease.

The study is published this week in Nature Materials and involved a trans-disciplinary partnership between biologists, materials scientists and physicists based in the UK, Spain and the USA.

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

Tracking intracellular forces and mechanical property changes in mouse one-cell embryo development by Marta Duch, Núria Torras, Maki Asami, Toru Suzuki, María Isabel Arjona, Rodrigo Gómez-Martínez, Matthew D. VerMilyea, Robert Castilla, José Antonio Plaza & Anthony C. F. Perry. Nature Materials (2020) DOI: https://doi.org/10.1038/s41563-020-0685-9 Published 25 May 2020

This paper is behind a paywall.

Implanted biosensors could help sports professionals spy on themselves

A May 21, 2020 news item on Nanowerk describes the latest in sports self-monitoring research (or as I like to think of it, spying on yourself),

Researchers from the University of Surrey have revealed their new biodegradable motion sensor – paving the way for implanted nanotechnology that could help future sports professionals better monitor their movements to aid rapid improvements, or help caregivers remotely monitor people living with dementia.

A May 21, 12020 University of Surrey press release (also on EurekAlert), which originated the news item, mentioned the collaboration with a South Korean University and provides a few details about this work,

In a paper published by Nano Energy, a team from Surrey’s Advanced Technology Institute (ATI), in partnership with Kyung Hee University in South Korea, detail how they developed a nano-biomedical motion sensor which can be paired with AI systems to recognise movements of distinct body parts.

The ATI’s technology builds on its previous work around triboelectric nanogenerators (TENG), where researchers used the technology to harness human movements and generate small amounts of electrical energy. Combining the two means self-powered sensors are possible without the need for chemical or wired power sources.

In their new research, the team from the ATI developed a flexible, biodegradable and long-lasting TENG from silk cocoon waste. They used a new alcohol treatment technique, which leads to greater durability for the device, even under harsh or humid environments.

Dr. Bhaskar Dudem, project lead and Research Fellow at the ATI, said: “We are excited to show the world the immense potential of our durable, silk film based nanogenerator. It’s ability to work in severe environments while being able to generate electricity and monitor human movements positions our TENG in a class of its own when it comes to the technology.”

Professor Ravi Silva, Director of the ATI, said: “We are proud of Dr Dudem’s work which is helping the ATI lead the way in developing wearable, flexible, and biocompatible TENGs that efficiently harvest environmental energies. If we are to live in a future where autonomous sensing and detecting of pathogens is important, the ability to create both self-powered and wireless biosensors linked to AI is a significant boost.”

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

Exploring theoretical and experimental optimization towards high-performance triboelectric nanogenerators using microarchitecture silk cocoon films by Bhaskar Dudem, R.D. Ishara G. Dharmasena, Sontyana Adonijah Graham, Jung Woo Leem, Harishkumarreddy Patnam, Anki Reddy Mule, S. Ravi P. Silva, Jae Su Yu. Nano Energy DOI: https://doi.org/10.1016/j.nanoen.2020.104882 Available online 11 May 2020, 104882

This paper is behind a paywall.

US Food and Drug Administration (FDA) gives first authorization for CRISPR (clustered regularly interspersed short palindromic repeats) use in COVID-19 crisis

Clustered regularly interspersed short palindromic repeats (CRISPR) gene editing has been largely confined to laboratory use or tested in agricultural trials. I believe that is true worldwide excepting the CRISPR twin scandal. (There are numerous postings about the CRISPR twins here including a Nov. 28, 2018 post, a May 17, 2019 post, and a June 20, 2019 post. Update: It was reported (3rd. para.) in December 2019 that He had been sentenced to three years jail time.)

Connie Lin in a May 7, 2020 article for Fast Company reports on this surprising decision by the US Food and Drug Administration (FDA), Note: A link has been removed),

The U.S. Food and Drug Administration has granted Emergency Use Authorization to a COVID-19 test that uses controversial gene-editing technology CRISPR.

This marks the first time CRISPR has been authorized by the FDA, although only for the purpose of detecting the coronavirus, and not for its far more contentious applications. The new test kit, developed by Cambridge, Massachusetts-based Sherlock Biosciences, will be deployed in laboratories certified to carry out high-complexity procedures and is “rapid,” returning results in about an hour as opposed to those that rely on the standard polymerase chain reaction method, which typically requires six hours.

The announcement was made in the FDA’s Coronavirus (COVID-19) Update: May 7, 2020 Daily Roundup (4th item in the bulleted list), Or, you can read the May 6, 2020 letter (PDF) sent to John Vozella of Sherlock Biosciences by the FDA.

As well, there’s the May 7, 2020 Sherlock BioSciences news release (the most informative of the lot),

Sherlock Biosciences, an Engineering Biology company dedicated to making diagnostic testing better, faster and more affordable, today announced the company has received Emergency Use Authorization (EUA) from the U.S. Food and Drug Administration (FDA) for its Sherlock™ CRISPR SARS-CoV-2 kit for the detection of the virus that causes COVID-19, providing results in approximately one hour.

“While it has only been a little over a year since the launch of Sherlock Biosciences, today we have made history with the very first FDA-authorized use of CRISPR technology, which will be used to rapidly identify the virus that causes COVID-19,” said Rahul Dhanda, co-founder, president and CEO of Sherlock Biosciences. “We are committed to providing this initial wave of testing kits to physicians, laboratory experts and researchers worldwide to enable them to assist frontline workers leading the charge against this pandemic.”

The Sherlock™ CRISPR SARS-CoV-2 test kit is designed for use in laboratories certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA), 42 U.S.C. §263a, to perform high complexity tests. Based on the SHERLOCK method, which stands for Specific High-sensitivity Enzymatic Reporter unLOCKing, the kit works by programming a CRISPR molecule to detect the presence of a specific genetic signature – in this case, the genetic signature for SARS-CoV-2 – in a nasal swab, nasopharyngeal swab, oropharyngeal swab or bronchoalveolar lavage (BAL) specimen. When the signature is found, the CRISPR enzyme is activated and releases a detectable signal. In addition to SHERLOCK, the company is also developing its INSPECTR™ platform to create an instrument-free, handheld test – similar to that of an at-home pregnancy test – that utilizes Sherlock Biosciences’ Synthetic Biology platform to provide rapid detection of a genetic match of the SARS-CoV-2 virus.

“When our lab collaborated with Dr. Feng Zhang’s team to develop SHERLOCK, we believed that this CRISPR-based diagnostic method would have a significant impact on global health,” said James J. Collins, co-founder and board member of Sherlock Biosciences and Termeer Professor of Medical Engineering and Science for MIT’s Institute for Medical Engineering and Science (IMES) and Department of Biological Engineering. “During what is a major healthcare crisis across the globe, we are heartened that the first FDA-authorized use of CRISPR will aid in the fight against this global COVID-19 pandemic.”

Access to rapid diagnostics is critical for combating this pandemic and is a primary focus for Sherlock Biosciences co-founder and board member, David R. Walt, Ph.D., who co-leads the Mass [Massachusetts] General Brigham Center for COVID Innovation.

“SHERLOCK enables rapid identification of a single alteration in a DNA or RNA sequence in a single molecule,” said Dr. Walt. “That precision, coupled with its capability to be deployed to multiplex over 100 targets or as a simple point-of-care system, will make it a critical addition to the arsenal of rapid diagnostics already being used to detect COVID-19.”

This development is particularly interesting since there was a major intellectual property dispute over CRISPR between the Broad Institute (a Harvard University and Massachusetts Institute of Technology [MIT] joint initiative), and the University of California at Berkeley (UC Berkeley). The Broad Institute mostly won in the first round of the patent fight, as I noted in a March 15, 2017 post but, as far as I’m aware, UC Berkeley is still disputing that decision.

In the period before receiving authorization, it appears that Sherlock Biosciences was doing a little public relations and ‘consciousness raising’ work. Here’s a sample from a May 5, 2020 article by Sharon Begley for STAT (Note: Links have been removed),

The revolutionary genetic technique better known for its potential to cure thousands of inherited diseases could also solve the challenge of Covid-19 diagnostic testing, scientists announced on Tuesday. A team headed by biologist Feng Zhang of the McGovern Institute at MIT and the Broad Institute has repurposed the genome-editing tool CRISPR into a test able to quickly detect as few as 100 coronavirus particles in a swab or saliva sample.

Crucially, the technique, dubbed a “one pot” protocol, works in a single test tube and does not require the many specialty chemicals, or reagents, whose shortage has hampered the rollout of widespread Covid-19 testing in the U.S. It takes about an hour to get results, requires minimal handling, and in preliminary studies has been highly accurate, Zhang told STAT. He and his colleagues, led by the McGovern’s Jonathan Gootenberg and Omar Abudayyeh, released the protocol on their STOPCovid.science website.

Because the test has not been approved by the Food and Drug Administration, it is only for research purposes for now. But minutes before speaking to STAT on Monday, Zhang and his colleagues were on a conference call with FDA officials about what they needed to do to receive an “emergency use authorization” that would allow clinical use of the test. The FDA has used EUAs to fast-track Covid-19 diagnostics as well as experimental therapies, including remdesivir, after less extensive testing than usually required.

For an EUA, the agency will require the scientists to validate the test, which they call STOPCovid, on dozens to hundreds of samples. Although “it is still early in the process,” Zhang said, he and his colleagues are confident enough in its accuracy that they are conferring with potential commercial partners who could turn the test into a cartridge-like device, similar to a pregnancy test, enabling Covid-19 testing at doctor offices and other point-of-care sites.

“It could potentially even be used at home or at workplaces,” Zhang said. “It’s inexpensive, does not require a lab, and can return results within an hour using a paper strip, not unlike a pregnancy test. This helps address the urgent need for widespread, accurate, inexpensive, and accessible Covid-19 testing.” Public health experts say the availability of such a test is one of the keys to safely reopening society, which will require widespread testing, and then tracing and possibly isolating the contacts of those who test positive.

If you have time, do read Begley’s in full.

Point-of-care diagnostics made easier to read with silver nanocubes

Researchers have shown that plasmonics can enhance the fluorescent markers used to signal positive samples in certain types of tests for diseases. A polymer brush coating keeps unwanted biomolecules away while a capture antibody (red) catches biomarkers of disease (clear). A detection antibody (blue) then latches on to the biomarker and emits light from an attached fluorophore (sphere). All of this is sandwiched by a thin layer of gold and a silver nanocube that is attached by a third antibody (green), creating conditions for the fluorophore to emit brighter light. Courtesy: Duke University

A May 12, 2020 news item on Nanowerk announces new work from scientists at Duke University on making point-of-care diagnostics easier to use by making the readouts brighter,

Engineers at Duke University [North Carolina, US] have shown that nanosized silver cubes can make diagnostic tests that rely on fluorescence easier to read by making them more than 150 times brighter. Combined with an emerging point-of-care diagnostic platform already shown capable of detecting small traces of viruses and other biomarkers, the approach could allow such tests to become much cheaper and more widespread.

A May 12, 2020 Duke University news release (also on EurekAlert), which originated the news item, provides more detail about the work,

Plasmonics is a scientific field that traps energy in a feedback loop called a plasmon onto the surface of silver nanocubes. When fluorescent molecules are sandwiched between one of these nanocubes and a metal surface, the interaction between their electromagnetic fields causes the molecules to emit light much more vigorously. Maiken Mikkelsen, the James N. and Elizabeth H. Barton Associate Professor of Electrical and Computer Engineering at Duke, has been working with her laboratory at Duke to create new types of hyperspectral cameras and superfast optical signals using plasmonics for nearly a decade.

At the same time, researchers in the laboratory of Ashutosh Chilkoti, the Alan L. Kaganov Distinguished Professor of Biomedical Engineering, have been working on a self-contained, point-of-care diagnostic test that can pick out trace amounts of specific biomarkers from biomedical fluids such as blood. But because the tests rely on fluorescent markers to indicate the presence of the biomarkers, seeing the faint light of a barely positive test requires expensive and bulky equipment.

“Our research has already shown that plasmonics can enhance the brightness of fluorescent molecules tens of thousands of times over,” said Mikkelsen. “Using it to enhance diagnostic assays that are limited by their fluorescence was clearly a very exciting idea.”

“There are not a lot of examples of people using plasmon-enhanced fluorescence for point-of-care diagnostics, and the few that exist have not been yet implemented into clinical practice,” added Daria Semeniak, a graduate student in Chilkoti’s laboratory. “It’s taken us a couple of years, but we think we’ve developed a system that can work.”

In the new paper, researchers from the Chilkoti lab build their super-sensitive diagnostic platform called the D4 Assay onto a thin film of gold, the preferred yin to the plasmonic silver nanocube’s yang. The platform starts with a thin layer of polymer brush coating, which stops anything from sticking to the gold surface that the researchers don’t want to stick there. The researchers then use an ink-jet printer to attach two groups of molecules tailored to latch on to the biomarker that the test is trying to detect. One set is attached permanently to the gold surface and catches one part of the biomarker. The other is washed off of the surface once the test begins, attaches itself to another piece of the biomarker, and flashes light to indicate it’s found its target.

After several minutes pass to allow the reactions to occur, the rest of the sample is washed away, leaving behind only the molecules that have managed to find their biomarker matches, floating like fluorescent beacons tethered to a golden floor.

“The real significance of the assay is the polymer brush coating,” said Chilkoti. “The polymer brush allows us to store all of the tools we need on the chip while maintaining a simple design.”

While the D4 Assay is very good at grabbing small traces of specific biomarkers, if there are only trace amounts, the fluorescent beacons can be difficult to see. The challenge for Mikkelsen and her colleagues was to place their plasmonic silver nanocubes above the beacons in such a way that they supercharged the beacons’ fluorescence.

But as is usually the case, this was easier said than done.

“The distance between the silver nanocubes and the gold film dictates how much brighter the fluorescent molecule becomes,” said Daniela Cruz, a graduate student working in Mikkelsen’s laboratory. “Our challenge was to make the polymer brush coating thick enough to capture the biomarkers–and only the biomarkers of interest–but thin enough to still enhance the diagnostic lights.”

The researchers attempted two approaches to solve this Goldilocks riddle. They first added an electrostatic layer that binds to the detector molecules that carry the fluorescent proteins, creating a sort of “second floor” that the silver nanocubes could sit on top of. They also tried functionalizing the silver nanocubes so that they would stick directly to individual detector molecules on a one-on-one basis.

While both approaches succeeded in boosting the amount of light coming from the beacons, the former showed the best improvement, increasing its fluorescence by more than 150 times. However, this method also requires an extra step of creating a “second floor,” which adds another hurdle to engineering a way to make this work on a commercial point-of-care diagnostic rather than only in a laboratory. And while the fluorescence didn’t improve as much in the second approach, the test’s accuracy did.

“Building microfluidic lab-on-a-chip devices through either approach would take time and resources, but they’re both doable in theory,” said Cassio Fontes, a graduate student in the Chilkoti laboratory. “That’s what the D4 Assay is moving toward.”

And the project is moving forward. Earlier in the year, the researchers used preliminary results from this research to secure a five-year, $3.4 million R01 research award from the National Heart, Lung, and Blood Institute. The collaborators will be working to optimize these fluorescence enhancements while integrating wells, microfluidic channels and other low-cost solutions into a single-step diagnostic device that can run through all of these steps automatically and be read by a common smartphone camera in a low-cost device.

“One of the big challenges in point-of-care tests is the ability to read out results, which usually requires very expensive detectors,” said Mikkelsen. “That’s a major roadblock to having disposable tests to allow patients to monitor chronic diseases at home or for use in low-resource settings. We see this technology not only as a way to get around that bottleneck, but also as a way to enhance the accuracy and threshold of these diagnostic devices.”

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

Ultrabright Fluorescence Readout of an Ink-Jet Printed Immunoassay Using Plasmonic Nanogap Cavities by Daniela F. Cruz, Cassio M. Fontes, Daria Semeniak, Jiani Huang, Angus Hucknall, Ashutosh Chilkoti, Maiken H. Mikkelsen. Nano Lett. 2020, XXXX, XXX, XXX-XXX DOI: https://doi.org/10.1021/acs.nanolett.0c01051 Publication Date:May 6, 2020 Copyright © 2020 American Chemical Society

This paper is behind a paywall.

Gas nanomedicine

This study comes from China and it offers an overview of the state-of-the-art of gas nanomedicine and a roadmap for future research. A May 6, 2020 news item on Nanowerk announces the study,

Cancer is deadly, but available cancer treatment methods are quite limited. The use of therapeutic gas molecules such as H2 [hydrogen gas], NO [nitrogen oxide], CO [carbon monoxide] and H2S [hydrogn sulfide] for cancer treatment is promising owing to their unique properties for selectively killing cancer cells and protecting normal cells from damage from other traditional therapies.

However, these gases and most of their prodrugs lack the abilities of active intratumoral accumulation and controlled gas release, causing limited therapeutic efficacy and potential side effects. The development of precision and intelligent gas delivery nanomedicines can maximize the profits of gas therapy by enhancing the bio-availability and bio-safety of therapeutic gases.

More and more gas-releasing nanomedicines are being developed by virtue of multifunctional nanoplatforms, making it ever-increasingly expectable to make breakthrough in cancer treatment. Even so, there are still many gaps between gas therapy and nanomedicines, needing to be filled.

In a new overview published in the Beijing-based National Science Review, scientists at Shenzhen University, China propose a series of engineering strategies of advanced gas-releasing nanomedicines for augmented cancer therapy from four aspects, 1) stimuli-responsive strategies for controlled gas release, 2) catalytic strategies for controlled gas release, 3) tumor-targeted gas delivery strategies, 4) multi-model combination strategies based on gas therapy.

A May 6, 2020 China Science Press news release on EurekAlert, which originated the news item, provides a little more detail about the overview and about a future application as an assistive therapy in diseases such as coronovirus pneumonia,

“This review systematically dissects the roles of carrier and gas prodrug within nanomedicine for stimuli-responsive gas release, catalytic gas generation routes, tumor-targeted gas delivery approaches and gas therapy-based combination methods, and also provides an insight into their engineering principles and working mechanisms, and correspondingly proposed a series of superior engineering strategies of nanomedicines for gas therapy of cancer to guide the future research.” Dr. Yingshuai Wang said “We believe this review could provide inspiration for constructing advanced gas-releasing nanomedicines.”

Moreover, they have also pointed out current issues and gaps in knowledge, and have envisaged current trends and future prospects of advanced nanomedicines for gas therapy of cancer in this review.

“There are many gaps intriguing me, such as high tissue penetration stimuli-responsive gas release, the local, endless and prodrug-free generation of gases by catalysis, and the super ability of assisting other almost all therapies.” Prof. Qianjun He adds “It is noticeable, in the recent fight of novel coronavirus pneumonia, hydrogen therapy is playing an vitally important role in assisting large numbers of patients to improve oxygen inhalation, relieve hypoxia, and scavenge inflammation. I hope our hydrogen-producing medicines would make bigger contribution to human being in the near future.”

This illustration accompanies the news release,

Caption: Illustration of strategies for engineering advanced nanomedicines for augmented gas therapy of cancer. Credit: ©Science China Press

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

Strategies for engineering advanced nanomedicines for gas therapy of cancer by Yingshuai Wang, Tian Yang, Qianjun He. National Science Review, nwaa034, https://doi.org/10.1093/nsr/nwaa034 Published: 27 February 2020

This appears to be an open access paper in PDF only.

For anyone new to the term, a prodrug is (Note: Links have been removed),

A prodrug is a medication or compound that, after administration, is metabolized (i.e., converted within the body) into a pharmacologically active drug.[1][2] Inactive prodrugs are pharmacologically inactive medications that are metabolized into an active form within the body. Instead of administering a drug directly, a corresponding prodrug might be used instead to improve how a medicine is absorbed, distributed, metabolized, and excreted (ADME).[3][4]

You can find out more in the Prodrug Wikipedia entry.