New CRISPR face mask could help us fight Covid-19 variants

Even as the U.S. surges into a mask-free summer, for many of us the experience of the Covid-19 pandemic has irrevocably changed how we view the spread of pathogens and viruses.

Getting a cold or even the flu used to just be a, largely inevitable, part of life. But now we’re painfully aware that each sniffling person we pass or squeeze next to on the subway could be harboring invisible pathogens on the hunt for their next host.

But what if those pathogens were no longer invisible? In research published Monday in Nature Biotechnology, a team of researchers from Harvard and MIT designed a face mask — as well as a slew of other wearables — that can detect pathogens in just a matter of minutes. No wires required.

Thanks to CRISPR technology baked inside, Peter Nguyen, a research scientist at Harvard and co-author on the study, tells Inverse these wearables go far beyond what your FitBit could ever hope to achieve.

“Current commercially available wearables (e.g., FitBit or Apple Watch) detect physiological signals electronically,” explains Nguyen, such as heart rate. “However, they cannot detect exposure to a pathogen or a toxin. That is something that currently requires an entire laboratory to process samples.”

“Our sensors can now bring that same testing power to wearables to detect and identify pathogens (any bacteria or virus) as well as toxins,” he says. “In essence, our technology miniaturizes an entire laboratory onto a wearable garment!”

What’s new — There are all kinds of wearables being developed in scientific labs that can detect more than just heart rate, including slurping sweat to evaluate your body’s health, but Luis Soenksen, a co-author on the study and venture builder for AI+Health at MIT, tells Inverse that so-called “cell-free” technology used in their wearables is much trickier to produce.

In these reactions, sensors are built to replicate the proteins used by cells to detect invading pathogens. You can think of these sensors kind of like the canary in the coal mine that gives scientists an alert (via color-changing or luminance) when a pathogen is found. Keeping these sensors “alive” and happy in order to make the detection though can be challenging, which is why the team decided to freeze-dry theirs instead and only “wake” them when ready for detection.

“To our knowledge, these are the first demonstration of wearable materials such as fabrics that have been engineered to harness the sensing mechanisms of biological systems in a user-safe and programmable format... with sensitivities that can rival state-of-the-art laboratory-based quantitative methods,” Soenksen says. “No wearable in the market can do this level of molecular sensing.”

Why it matters — Because their device can be programmed to detect “virtually any pathogen,” says Nguyen, the sky’s the limit when it comes to how these devices could be used to transform the detection and monitoring of hyper-local viruses or virus variants.

In addition to testing their wearables, which include clothing as well as masks, the team also demonstrated that pathogens like Ebola, MRSA, and even deadly nerve agents could also be quickly detected.

In rural areas with little to no access to laboratories to process disease samples, these power-free masks could play a huge role in detecting and minimizing the spread of disease early.

What they did — To train their wearables to detect different pathogens or viruses, the team had to first train CRISPR enzymes to recognize those diseases as well.

“CRISPR enzymes can be easily programmed to very specifically target and cut any desired nucleic acid,” explains Nguyen. “Some CRISPR enzymes, once they find the matching target and cut it, then switch into a form where they indiscriminately chew up all nucleic acids.” — a crucial component of DNA and RNA — “We use this unique property to develop it into a sensor, where we add in artificial nucleic acids that emit light when they are cut.”

These biological circuits were then freeze-dried and woven into various wearables, including a mask and jacket.

Using a human-like aspiration model, the team tested how quickly their SARS-CoV-2 — the virus that causes Covid-19 — could detect and alert wearers to illness.

“After about 5 to 30 minutes, a simple button in the mask gets pressed, which then triggers a capillary mechanism that runs the full analysis to produce a visible colorimetric signal that confirms the status of the patient,” says Soenksen. In other words, pressing the button triggers the CRISPR enzymes to chew up the sample for evaluation.

Nguyen adds that their mask sensors “combine the speed and convenience of rapid antigen tests with the sensitivity of RT-PCR tests” and could be effective at distinguishing between newly emerging Covid variants.

What’s next — These Covid-19 detecting masks aren’t quite ready to hit a CVS near you, but Soenksen says they’re actively looking for commercial partners to help them manufacture the masks for roughly $5 each.

“The Covid-19 face masks are inexpensive enough that they could be used anywhere by anyone,” says Nguyen.

“They would especially be useful in situations where local variant outbreaks occur, allowing a population to conveniently test themselves at home multiple times a day. The results would be produced at home without the need to visit or mail a sample to a laboratory.”

Abstract: Integrating synthetic biology into wearables could expand opportunities for noninvasive monitoring of physiological status, disease states and exposure to pathogens or toxins. However, the operation of synthetic circuits generally requires the presence of living, engineered bacteria, which has limited their application in wearables. Here we report lightweight, flexible substrates and textiles functionalized with freeze-dried, cell-free synthetic circuits, including CRISPR-based tools, that detect metabolites, chemicals and pathogen nucleic acid signatures. The wearable devices are activated upon rehydration from aqueous exposure events and report the presence of specific molecular targets by colorimetric changes or via an optical fiber network that detects fluorescent and luminescent outputs. The detection limits for nucleic acids rival current laboratory methods such as quantitative PCR. We demonstrate the development of a face mask with a lyophilized CRISPR sensor for wearable, noninvasive detection of SARS-CoV-2 at room temperature within 90 min, requiring no user intervention other than the press of a button.