Pandemics were top of mind for Jim Collins years before the new coronavirus emerged.
In 2014, his bioengineering laboratory at MIT began developing sensors that could detect the Ebola virus when it was freeze-dried onto a piece of paper. The small team of scientists from MIT and Harvard first published their research in 2016; by then, they’d tailored the technology to address the growing Zika virus threat. Now, they’re adjusting their tool again to identify coronavirus cases.
The team is developing a face mask that produces a fluorescent signal when a person with the coronavirus breathes, coughs, or sneezes. If the technology proves successful, it could address flaws associated with other screening methods like temperature checks.
“As we open up our transit system, you could envision it being used in airports as we go through security, as we wait to get on a plane,” Collins said. “You or I could use it on the way to and from work. Hospitals could use it for patients as they come in or wait in the waiting room as a pre-screen of who’s infected.”
Doctors could even use them to diagnose patients on the spot, without having to send samples to a laboratory. At a time when testing snafus and delays have hampered many countries’ ability to control outbreaks, tools that quickly identify patients are critical.
Collins said his lab’s current project is in the “very early stages”, but the results have been promising. For the last few weeks, his team has been testing the sensors’ ability to detect coronavirus in a small saliva sample.
They’re also experimenting with design: right now, the lab is debating whether to embed sensors on the inside of a mask or develop a module that can be attached to any over-the-counter mask.
The team hopes to demonstrate that the concept actually works within the next few weeks.
“Once we’re in that stage, then it would be a matter setting up trials with individuals expected to be infected to see if it would work in a real-world setting,” Collins said.
The virus-identifying technology more generally, however, has already been proven. By 2018, the lab’s sensors could detect Sars, measles, influenza, hepatitis C, West Nile, and other viruses.
“We initially did this on paper to create inexpensive paper-based diagnostics,” Collins said. “We’ve shown it can work on plastic, quartz, as well as cloth.”
Collins’ sensors consist of genetic material – DNA and RNA – that binds to a virus. That material is freeze-dried onto fabric using a machine called a lyophiliser, which sucks moisture out of the genetic material without killing it. It can remain stable at room temperature for several months, giving the masks a relatively long shelf life.
The sensors need two things to be activated. The first is moisture, which our bodies give off through respiratory particles like mucus or saliva. Second, they need to detect a virus’ genetic sequence.
A Shanghai laboratory sequenced the coronavirus genome in January. Collins said his sensors only need to identify a small segment of that sequence to spot the virus. Once they do, they give off a fluorescent signal within one to three hours.
That signal isn’t visible to the naked eye, so Collins’ lab uses a device called a flourimetre to measure the fluorescent light. Outside the lab, he said, public officials could use handheld flourimetre – which Collins said “cost about a dollar” – to scan people’s masks.
His team has also previously developed sensors that change from yellow to purple when a virus is present, so colour-changing sensors are a possibility too, he said, though the group has tabled that idea for now.
Collins is considered a pioneer of synthetic biology, a field that uses engineering to redesign systems found in nature. He won a MacArthur genius grant in 2003. In 2018, his lab got a US$50,000 grant from Johnson & Johnson to develop embeddable virus-detecting sensors for lab coats.
The sensors might offer a cheaper, quicker, and more sensitive form of detection than traditional diagnostic tests. The lab’s sensors for Zika, for example, can diagnose patients within two to three hours. The team estimated in 2016 that the sensors cost around US$20 each, while the test itself was US$1 or less to manufacture.
Coronavirus tests, by contrast, currently take about 24 hours to run, and patients often don’t receive results for several days. That could change, however, now that the FDA has authorised an at-home diagnostic test (it’s currently being distributed to health care workers and first responders).
The test developed by the Centres for Disease Control and Prevention costs around US$36, according to a document released by Medicare in March. For commercial labs, the price is US$51.
Because Collins’ sensors are highly specific, they’re even able to detect different strains of a virus. In the case of Zika, the sensors picked up two strains from Africa, one from Asia, and another from America.
Scientists have traced coronavirus strains back to two main lineages: one that originated in Asia and another that has become more common in Europe, North America, and Australia. Though MIT lab is still testing coronavirus segments, there’s a good chance that its technology will be able to detect these differences: The team previously found that their test had a 48 per cent probability of identifying a single point mutation.
Airport screeners often rely on temperature checks to flag potential coronavirus cases among travellers. The method is also being used to spot potential infections in countries that have relaxed lockdown restrictions.
But temperature checks miss a large swathe of infections, including patients who are asymptomatic, pre-symptomatic, or experiencing symptoms other than a fever. Collins thinks his sensors could identify more cases by detecting the virus itself, rather than its symptoms.
The lab’s aspirational goal, he said, is to begin manufacturing masks for public distribution by the end of summer.
“Right now we’re time-constrained and talent-constrained in that we’ve got a relatively small team,” he said. “We’re limited in how many we can have in the lab working and they’re all working as hard as they can.”