Study shows clinical laboratories may one day use nanorobotic tests to help prevent spread of viral infections, cancer, and other diseases
Scientists from the University of Illinois Urbana-Champaign (U of I) have developed a tiny robotic “hand” made from structural DNA that “grabs” viruses—including the COVID-19 coronavirus—potentially preventing them from infecting cells. Such a nano-robotic antiviral technology could be used by anatomic pathologists and clinical laboratory managers in the future as a point-of-care type of test.
This is yet another example of out-of-the-box thinking by developers of diagnostic technology. Led by Xing Wang, PhD, professor of bioengineering and of chemistry at the U of I, the scientists dubbed their DNA device the NanoGripper.
Similar to a piece of origami (Japanese art of folded paper), the so-called hand has “four bendable fingers and a palm, all in one nanostructure folded from a single piece of DNA,” according to a U of I news release. The scientists found in their study that the hand was capable of doing a rapid test to identify the (COVID-19) virus and “prevented the viral spike proteins from infecting the cells,” Gizmodo reported.
“We are using DNA for its structural properties. It is strong, flexible, and programmable. Yet even in the DNA origami field, this is novel in terms of the design principle. We fold one long strand of DNA back and forth to make all of the elements, both the static and moving pieces, in one step,” said Wang in the news release.
“It would be very difficult to apply it after a person is infected, but there’s a way we could use it as a preventive therapeutic,” said Xing Wang, PhD (above), associate professor, bioengineering and chemistry, University of Illinois Urbana-Champaign, in a news release. “We could make an anti-viral nasal spray compound. The nose is the hot spot for respiratory viruses, like COVID or influenza. A nasal spray with the NanoGripper could prevent inhaled viruses from interacting with the cells in the nose.” Clinical laboratories may one day perform antiviral testing that uses U of I’s NanoGripper technology. (Photo copyright: University of Illinois.)
How a DNA Nanorobot Grabs a Virus
The U of I researchers wanted to leverage what has been discovered about DNA as a “material for constructing versatile nanorobots for biomedical applications,” they wrote in Science Robotics. However, previous studies had not achieved the current origami design of a nanoscale mechanism, the authors added.
With robotic precision and its DNA structure, the researchers’ NanoGripper moves and enables fingers to bend for “customized interactions with target molecules,” Interesting Engineering reported, adding that the technology also:
Employed DNA aptamers on the fingers which act as “molecular locks” to find and bind to specific targets.
In a demonstration, wrapped its fingers around the target spike protein of the COVID-19 coronavirus, essentially “disabling its ability to infect cells.”
“The aptamers are arranged into a spatial pattern that specifically matches that of the trimeric spike protein on the virus outer surface. Such pattern recognition-enabled multivalent interaction—a principle developed by my group—has induced ultrahigh NanoGripper virus-binding avidity, resulting in enhanced virus diagnosis sensitivity,” Wang said.
Taken from the U of I news release, the image above shows how “Inspired by the gripping power of the human hand and bird claws, the researchers designed the NanoGripper with four bendable fingers and a palm, all in one nanostructure folded from a single piece of DNA. Each finger has three joints, like a human finger, and the angle and degree of bending are determined by the design on the DNA scaffold.” Such nano-robotic technology could become a new clinical laboratory test for diagnosing viral infections, or even a preventative treatment if caught prior to infection. (Photo and caption copyright: University of Illinois.)
Developing a Test for COVID-19
The scientists discovered that when equipped with a photonic crystal sensor, NanoGripper detected the SARS-CoV-2 coronavirus in 30 minutes with sensitivity equal to RTqPCR tests, Gizmodo reported.
“The NanoGripper functions as a highly sensitive biosensor that selectively detects intact SARS-CoV-2 virions in human saliva with a limit of detection of 100 copies per milliliter, providing a sensitivity equal to that of reverse transcription quantitative polymerase chain reaction [RTqPCR],” the authors wrote in Science Robotics.
In fact, the NanoGripper test is reportedly faster and easier than RTqPCR testing, which requires sophisticated instruments.
“Our test is very fast and simple since we detect the intact virus directly,” said study collaborator Brian Cunningham, PhD, professor, electrical and computer engineering and bioengineering at U of I, in the news release.
“When the virus is held in the NanoGripper’s hand, a fluorescent molecule is triggered to release light when illuminated by an LED or laser,” he said, adding, “When a large number of fluorescent molecules are concentrated upon a single virus, it becomes bright enough in our detection system to count each virus individually.”
More Research and Applications
Gizmodo compared the NanoGripper to a “true Swiss army knife,” able to change and detect other viruses such as HIV and influenza (Flu).
The U of I researchers have already studied the NanoGripper’s ability to detect hepatitis B and plan to publish findings soon, Wang told The Pathologist. He also noted it’s possible the NanoGripper “can be integrated with a lateral flow assay paper strip platform for development of a rapid, sensitive, and inexpensive at home or point-of-care virus detection.”
There is “power in soft nanorobotics,” said Wang, who envisions potential for the NanoGripper beyond viruses to include programming the fingers to detect cancer markers and enabling the grippers to deliver treatment to target cells.
Clinical pathologists and laboratory managers may want to follow this research coming out of the University of Illinois Urbana-Champaign. Once put through additional clinical studies, such nanorobotic diagnostic technology might eventually be used at the point-of-care to help prevent viral infection and spread of disease.
Study of the 50 Omicron variants could lead to new approaches to clinical laboratory testing and medical treatments for long COVID
Patients infected with SARS-CoV-2 can usually expect the COVID-19 illness to subside within a couple of weeks. However, one Dutch patient remained infected with the coronavirus for 612 days and fought more than 50 mutations (aka, variants) before dying late last year of complications due to pre-existing conditions. This extreme case has given doctors, virologists, microbiologists, and clinical laboratories new insights into how the SARS-CoV-2 virus mutates and may lead to new treatments for long COVID.
The medication the patient was taking for his pre-existing conditions may have contributed to his body being unable to produce antibodies in response to three shots of the Moderna mRNA COVID vaccine he received.
Magda Vergouwe, MD, PhD candidate at the Center for Experimental and Molecular Medicine (CEMM), Amsterdam UMC, who lead a study into the patient, theorized that some of the medications the patient was on for his pre-existing conditions could have destroyed healthy cells alongside the abnormal cancer-causing B cells the drugs were meant to target.
“This case underscores the risk of persistent SARS-CoV-2 infections in immunocompromised individuals,” the researchers said prior to presenting their report about the case at a meeting of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) in Barcelona, Spain, Time reported. “We emphasize the importance of continuing genomic surveillance of SARS-CoV-2 evolution in immunocompromised individuals with persistent infections.”
“Chronic infections and viral evolution [are] commonly described in [the] literature, and there are other cases of immunocompromised patients who have had [COVID] infections for hundreds of days,” Magda Vergouwe, MD, PhD candidate (above), Center for Experimental and Molecular Medicine at Amsterdam UMC, told Scientific American. “But this is unique due to the extreme length of the infection … and with the virus staying in his body for so long, it was possible for mutations to just develop and develop and develop.” Microbiologists, virologists, and clinical laboratories involved in testing patients with long COVID may want to follow this story. (Photo copyright: LinkedIn.)
Risks to Immunocompromised Patients
Pre-existing conditions increase the risk factor for COVID-19 infections. A 2021 study published in the Journal of the American Board of Family Medicine (JABFM) titled, “Prevalence of Pre-existing Conditions among Community Health Center Patients with COVID-19,” found that about 61% of that study’s test group had a pre-existing condition prior to the outbreak of the COVID-19 pandemic.
When the Dutch man was admitted to Amsterdam UMC with common and serious COVID-19 symptoms, such as shortness of breath, a cough, and low blood oxygen levels, he was prescribed sotrovimab (a monoclonal antibody) along with other COVID treatments.
About a month after being admitted his COVID-19 symptoms decreased, so he was first discharged to a rehab facility and then finally to his home. However, he continued to test positive for the coronavirus and developed other infections that may have been complicated by the persistent case of COVID-19.
The Amsterdam UMC doctors emphasized that the man ultimately succumbed to his pre-existing conditions and not necessarily COVID-19.
“It’s important to note that in the end he did not die from his COVID-19,” Vergouwe told Scientific American. “But he did keep it with him for a very long period of time until then, and this is why we made sure to sample [the virus in his body] as much as we could.”
One in Five Adults Develop Long COVID
Long COVID does not necessarily indicate an active infection. However, in as many as one in five US adults COVID symptoms persist after the acute phase of the infection is over, according to a study published recently in JAMA Network Open titled, “Epidemiologic Features of Recovery from SARS-CoV-2 Infection.”
“In this cohort study, more than one in five adults did not recover within three months of SARS-CoV-2 infection. Recovery within three months was less likely in women and those with pre-existing cardiovascular disease and more likely in those with COVID-19 vaccination or infection during the Omicron variant wave,” the JAMA authors wrote.
The origins of long COVID are not entirely clear, but according to the National Institutes of Health (NIH) it can develop when a patient is unable to sufficiently rest while battling off the initial virus. According to Vergouwe, the SARS-CoV-2 genome will always grow quicker when found in a patient with a compromised immune system.
Unique COVID-19 Mutations
More than 50 new mutations of the original Omicron variant were identified in the Dutch patient. According to Vergouwe, “while that number can sound shocking, mutations to the SARS-CoV-2 genome are expected to evolve more quickly in those who are immunocompromised (the average mutation rate of the virus is estimated to be two mutations per person per month),” Scientific American reported. “What does make these mutations unusual, she noted, is how their features differed vastly from mutations observed in other people with COVID. [Vergouwe] hypothesizes that the exceptional length of the individual’s infection, and his pre-existing conditions, allowed the virus to evolve extensively and uniquely.”
COVID-19 appears to be here to stay, and most clinical laboratory managers and pathologists understand why. As physicians continue to learn about the SARS-CoV-2 coronavirus, this is another example of how the knowledge about SARS-CoV-2 is growing as different individuals are infected with different variants of the virus.
HHS Office of Inspector General was the latest to examine the quality control problems that led to distribution of inaccurate test to clinical laboratories nationwide
Failure on the part of the Centers for Disease Control and Prevention (CDC) to produce accurate, dependable SARS-CoV-2 clinical laboratory test kits at the start of the COVID-19 pandemic continues to draw scrutiny and criticism of the actions taken by the federal agency.
In the early weeks of the COVID-19 pandemic, the CDC distributed faulty SARS-CoV-2 test kits to public health laboratories (PHLs), delaying the response to the outbreak at a critical juncture. That failure was widely publicized at the time. But within the past year, two reports have provided a more detailed look at the shortcomings that led to the snafu.
“We identified weaknesses in CDC’s COVID-19 test kit development processes and the agencywide laboratory quality processes that may have contributed to the failure of the initial COVID-19 test kits,” the OIG stated in its report.
Prior to the outbreak, the agency had internal documents that were supposed to provide guidance for how to respond to public health emergencies. However, “these documents do not address the development of a test kit,” the OIG stated.
“If the CDC can’t change, [its] importance in health in the nation will decline,” said microbiologist Jill Taylor, PhD (above), Senior Adviser for the Association of Public Health Laboratories in Washington, DC. “The coordination of public health emergency responses in the nation will be worse off.” Clinical laboratories that were blocked from developing their own SARS-CoV-2 test during the pandemic would certainly agree. (Photo copyright: Columbia University.)
Problems at the CDC’s RVD Lab
Much of the OIG’s report focused on the CDC’s Respiratory Virus Diagnostic (RVD) lab which was part of the CDC’s National Center for Immunization and Respiratory Diseases (NCIRD). The RVD lab had primary responsibility for developing, producing, and distributing the test kits. Because it was focused on research, it “was not set up to develop and manufacture test kits and therefore had no policies and procedures for developing and manufacturing test kits,” the report stated.
The RVD lab also lacked the staff and funding to handle test kit development in a public health emergency, the report stated. As a result, “the lead scientist not only managed but also participated in all test kit development processes,” the report stated. “In addition, when the initial test kit failed at some PHLs, the lead scientist was also responsible for troubleshooting and correcting the problem.”
To verify the test kit, the RVD lab needed samples of viral material from the agency’s Biotechnology Core Facility Branch (BCFB) CORE Lab, which also manufactured reagents for the kit.
“RVD Lab, which was under pressure to quickly create a test kit for the emerging health threat, insisted that CORE Lab deviate from its usual practices of segregating these two activities and fulfill orders for both reagents and viral material,” the report stated.
This increased the risk of contamination, the report said. An analysis by CDC scientists “did not determine whether a process error or contamination was at fault for the test kit failure; however, based on our interviews with CDC personnel, contamination could not be ruled out,” the report stated.
The report also cited the CDC’s lack of standardized systems for quality control and management of laboratory documents. Labs involved in test kit development used two different incompatible systems for tracking and managing documents, “resulting in staff being unable to distinguish between draft, obsolete, and current versions of laboratory procedures and forms.”
Outside Experts Weigh In
The OIG report followed an earlier review by the CDC’s Laboratory Workgroup (LW), which consists of 12 outside experts, including academics, clinical laboratory directors, state public health laboratory directors, and a science advisor from the Association of Public Health Laboratories. Members were appointed by the CDC Advisory Committee to the Director.
This group cited four major issues:
Lack of adequate planning: For the “rapid development, validation, manufacture, and distribution of a test for a novel pathogen.”
Ineffective governance: Three labs—the RVD Lab, CORE Lab, and Reagent and Diagnostic Services Branch—were involved in test kit development and manufacturing. “At no point, however, were these three laboratories brought together under unified leadership to develop the SARS-CoV-2 test,” the report stated.
Poor quality control and oversight: “Essentially, at the start of the pandemic, infectious disease clinical laboratories at CDC were not held to the same quality and regulatory standards that equivalent high-complexity public health, clinical and commercial reference laboratories in the United States are held,” the report stated.
Poor test design processes: The report noted that the test kit had three probes designed to bind to different parts of the SARS-CoV-2 nucleocapsid gene. The first two—N1 (topology) and N2 (intracellular localization)—were designed to match SARS-CoV-2 specifically, whereas the third—N3 (functions of the protein)—was designed to match all Sarbecoviruses, the family that includes SARS-CoV-2 as well as the coronavirus responsible for the 2002-2004 SARS outbreak.
The N1 probe was found to be contaminated, the group’s report stated, while the N3 probe was poorly designed. The report questioned the decision to include the N3 probe, which was not included in European tests.
Also lacking were “clearly defined pass/fail threshold criteria for test validation,” the report stated.
Advice to the CDC
Both reports made recommendations for changes at the CDC, but the LW’s were more far-reaching. For example, it advised the agency to establish a senior leader position “with major responsibility and authority for laboratories at the agency.” This individual would oversee a new Center that would “focus on clinical laboratory quality, laboratory safety, workforce training, readiness and response, and manufacturing.”
In addition, the CDC should consolidate its clinical diagnostic laboratories, the report advised, and “laboratories that follow a clinical quality management system should have separate technical staff and space from those that do not follow such a system, such as certain research laboratories.”
The report also called for collaboration with “high functioning public health laboratories, hospital and academic laboratories, and commercial reference laboratories.” For example, collaborating on test design and development “should eliminate the risk of a single point of failure for test design and validation,” the LW suggested.
CBS News reported in August that the CDC had already begun implementing some of the group’s suggestions, including agencywide quality standards and better coordination with state labs.
However, “recommendations for the agency to physically separate its clinical laboratories from its research laboratories, or to train researchers to uphold new quality standards, will be heavy lifts because they require continuous funding,” CBS News reported, citing an interview with Jim Pirkle, MD, PhD, Director, Division of Laboratory Sciences, National Center for Environmental Health, at the CDC.
Doctors report difficulty differentiating COVID-19 from other viral infections, impacting clinical laboratory test orders
Because the SARS-CoV-2 coronavirus is in the same family of viruses that cause the common cold and influenza, virologists expected this virus—which caused the global COVID-19 pandemic—would evolve and mutate into a milder form of infection. Early evidence from this influenza season seems consistent with these expectations in ways that will influence how clinical laboratories offer tests for different respiratory viruses.
While new variants of the SARS-CoV-2 virus continue to appear, indications are that early in this flu season individuals infected with the more recent variants are experiencing milder symptoms when compared to the last few years. Doctors report they find it increasingly difficult to distinguish COVID-19 infections from allergies or the common cold because patients’ symptoms are less severe, according to NBC News.
This, of course, makes it challenging for doctors to know the most appropriate clinical laboratory tests to order to help them make accurate diagnoses.
“It isn’t the same typical symptoms that we were seeing before. It’s a lot of congestion, sometimes sneezing, usually a mild sore throat,” Erick Eiting, MD, Vice Chair of Operations for Emergency Medicine at Mount Sinai Hospital in New York City, told NBC News. “Just about everyone who I’ve seen has had really mild symptoms. The only way that we knew that it was COVID was because we happened to be testing them.” Knowing which tests for respiratory viruses that clinical laboratories need to perform may soon be the challenge for doctors. (Photo copyright: Mt. Sinai.)
Milder COVID-19 Symptoms Follow a Pattern
Previous hallmarks of a COVID-19 infection included:
Loss of taste,
loss of smell,
dry cough,
fever,
sore throat,
diarrhea,
body aches,
headaches.
However, physicians now observe milder symptoms of the infection that follow a distinct pattern and which are mostly concentrated in the upper respiratory tract.
Grace McComsey, MD, Vice President of Research and Associate Chief Scientific Officer at University Hospitals Health System (UH) in Cleveland, Ohio, told NBC News that some patients have described their throat pain as “a burning sensation like they never had, even with Strep in the past.”
“Then, as soon as the congestion happens, it seems like the throat gets better,” she added.
In addition to the congestion, some patients are experiencing:
headache,
fever,
chills,
fatigue,
muscle aches,
post-nasal drip.
McComsey noted that fatigue and muscle aches usually only last a couple of days, but that the congestion can sometimes last a few weeks. She also estimated that only around 10-20% of her newest COVID patients are losing their sense of smell or taste, whereas early in the pandemic that number was closer to 60-70% of her patients.
Doctors also noted that fewer patients are requiring hospitalization and that many recover without the use of antivirals or other treatments.
“Especially since July, when this recent mini-surge started, younger people that have upper respiratory symptoms—cough, runny nose, sore throat, fever and chills—99% of the time they go home with supportive care,” said Michael Daignault, MD, an emergency physician at Providence Saint Joseph Medical Center in Burbank, California.
Milder SARS-CoV-2 Variants Should Still be Taken Seriously
Doctors have varying opinions regarding why the current COVID-19 variants are milder. Some believe the recent variants simply aren’t as good at infecting the lungs as previous variants.
“Overall, the severity of COVID-19 is much lower than it was a year ago and two years ago,” Dan Barouch, MD, PhD, Director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center, told NBC News. “That’s not because the variants are less robust. It’s because the immune responses are higher.”
McComsey added that she doesn’t think mild cases should be ignored as she is still seeing new cases of long COVID with rapid heart rate and exercise intolerance being among the most common lingering symptoms. Re-infections also add to the risks associated with long COVID.
“What we’re seeing in long COVID clinics is not just the older strains that continue to be symptomatic and not getting better—we’re adding to that number with the new strain as well,” McComsey said. “That’s why I’m not taking this new wave any less seriously.”
Clinical Laboratory COVID-19 Testing May Decrease
According to Andrew Read, PhD, Interim Senior Vice President for Research and Evan Pugh University Professor of Biology and Entomology at Pennsylvania State University, there is nothing unexpected or startling about the coronavirus acquiring new mutations.
“When a mutation confers an interesting new trick that’s got an advantage, it’s going to be popping up in many different places,” Read told the New York Times. “Everything we see is just consistent with how you imagine virus evolution proceeding in a situation where a new virus has jumped into a novel host population.”
Data from the Centers for Disease Control and Prevention’s COVID-19 Data Tracker—which reports weekly hospitalizations, deaths, emergency department (ED) visits, and COVID-19 test positivity results—shows infection trends fluctuating, but overall, they are decreasing.
For the week of October 21, 2023, there were 16,186 hospitalizations due to COVID-19 compared to the highest week recorded (January 15, 2022) with 150,674 hospitalizations nationwide.
The highest number of deaths reported in a single week were 25,974 for the week of January 8, 2021, while 637 patients perished from COVID-19 during the week of October 21, 2023.
In January of 2021, COVID accounted for 13.8% of all ED visits and in October 2023, COVID-19 was responsible for 1.3% of ED visits.
“What I think we’re seeing is the virus continuing to evolve, and then leading to waves of infection, hopefully mostly mild in severity,” Barouch told The New York Times.
As severity of COVID-19 infections continues to fall, so, presumably, will demand for COVID-19 testing which has been a source of revenue for clinical laboratories for several years.
Many clinical laboratory professionals are aware of the significant amount of waste going into landfills from spent COVID-19 rapid PCR tests that use biosensors to produce results. These biosensor systems “use printed circuit boards, or PCBs, the same materials used in computers. PCBs are difficult to recycle and slow to biodegrade, using large amounts of metal, plastic, and non-eco-friendly materials,” according to a Penn Engineering Today blog post.
UPenn’s new test does not use PCBs. Instead, its biosensor uses “bacterial cellulose (BC), an organic compound synthesized from several strains of bacteria,” the blog post noted.
“This new BC test is non-toxic, naturally biodegradable and both inexpensive and scalable to mass production, currently costing less than $4.00 per test to produce. Its cellulose fibers do not require the chemicals used to manufacture paper, and the test is almost entirely biodegradable,” the blog post continued.
“There is a need for biodegradable diagnostic testing,” said Cesar de la Fuente, PhD (above), Presidential Assistant Professor in the Psychiatry Department at the University of Pennsylvania’s Perelman School of Medicine. “We will be continuing to perfect this technology, which could hopefully help many people in the future, while also looking to expand it to other emerging pathogens in anticipation of future pandemics.” Clinical laboratories engaged in SARS-CoV-2 testing during the COVID-19 pandemic can attest to the massive amounts of waste generated by traditional PCR testing. (Photo copyright: University of Pennsylvania.)
Evolution of Improvement for SARS-CoV-2 Diagnostic Assays
Cesar de la Fuente, PhD, is Presidential Assistant Professor in the Psychiatry Department at the Perelman School of Medicine. His lab has been hard at work since the start of the pandemic to improve COVID-19 testing. The recent study was a collaboration between University of Pennsylvania’s de la Fuente Lab and William Reis de Araujo, Professor in Analytical Chemistry at the State University of Campinas (UNICAMP) in São Paulo, Brazil.
De Araujo leads the Portable Chemical Sensors Lab and has been pairing his electrochemistry expertise with de la Fuente’s lab for years, Penn Engineering Today noted.
The team wanted to combine the speed and cost-effectiveness of previous rapid tests with an eco-friendly biodegradable substrate material.
Bacterial cellulose (BC) was a great choice because it “naturally serves as a factory for the production of cellulose, a paper-like substance which can be used as the basis for biosensors,” Penn Engineering Today reported.
Additionally, BC has an excellent track record for a variety of uses, such as regenerative medicine, wound care, and point-of-care (POC) diagnostics, the blog post noted. UPenn’s test offers speed and accuracy without needing costly equipment making it desirable for clinical laboratories preparing to fight the next pandemic.
The test has shown to be capable of “correctly identifying multiple variants in under 10 minutes. This means that the tests won’t require ‘recalibration’ to accurately test for new variants,” Penn Engineering Today added.
Innovation Born from Inspiration
Though rapid tests are essential to help curb the spread of COVID-19, the negatives that come with these tests didn’t sit well with the UPenn team. This spurred them to strive for improvements.
PCR tests “are hampered by waste [metal, plastic, and the aforementioned PCBs]. They require significant time [results can take up to a day or more] as well as specialized equipment and labor, all of which increase costs,” Penn Engineering Today noted.
Additionally, “Sophistication of PCR tests makes them harder to tweak and therefore slower to respond to new variants,” the blog post concluded.
“There’s a tension between these two worlds of innovation and conservation,” de la Fuente told Penn Engineering Today. “When we create new technology, we have a responsibility to think through the consequences for the planet and to find ways to mitigate the environmental impact.”
Need for Biodegradable Diagnostic Tests
“COVID-19 has led to over 6.8 million deaths worldwide and continues to affect millions of people, primarily in low-income countries and communities with low vaccination coverage,” the Cell Reports Physical Science paper noted.
“There is a need for biodegradable diagnostic testing,” de la Fuentes told Penn Engineering Today. “We will be continuing to perfect this technology, which could hopefully help many people in the future, while also looking to expand it to other emerging pathogens in anticipation of future pandemics.”
While UPenn’s test will require clinical trials and FDA approval before it can become available to clinical laboratories and for point-of-care testing, it promises a bright, eco-friendly future for rapid viral testing.
