Clothing & facemask to detect pathogens and toxins and alert the wearer. Researchers from Harvard University’s Wyss Institute for Biologically Inspired Engineering and the Massachusetts Institute of Technology(MIT) have discovered a way to embed synthetic biology reactions into fabrics, resulting in wearable biosensors that can detect pathogens and toxins and alert the wearer.
The phrase “wearable” is usually associated with a fitness tracker, wristwatch, or wireless earbuds. But what if cutting-edge biotechnology was built into your clothing and could alert you when you were in danger? To identify the presence of the SARS-CoV-2 virus in a patient’s breath, the team has integrated this technology into ordinary face masks. The button-activated mask provides results in 90 minutes with accuracy comparable to traditional nucleic acid-based diagnostic techniques such as polymerase chain reactions (PCR). Nature Biotechnology published an article about the accomplishment.
“We have essentially shrunk an entire diagnostic laboratory down into a small, synthetic biology-based sensor that works with any face mask, and combines the high accuracy of PCR tests with the speed and low cost of antigen tests,” said co-first author Peter Nguyen, Ph.D., a Research Scientist at the Wyss Institute. “In addition to face masks, our programmable biosensors can be integrated into other garments to provide on-the-go detection of dangerous substances including viruses, bacteria, toxins, and chemical agents.”
“Our programmable biosensors can be integrated into other garments to provide on-the-go detection of dangerous substances including viruses, bacteria, toxins, and chemical agents” he added.
The SARS-CoV-2 biosensor is the result of three years of development on the team’s wearable freeze-dried cell-free (wFDCF) technology, which is based on previous iterations developed in Wyss Core Faculty member and senior author Jim Collins’ lab. The molecular machinery that cells utilize to read DNA and create RNA and proteins is extracted and freeze-dried in this procedure. These biological ingredients can be stored for a long time and are easy to activate by simply adding water. Biosensors with synthetic genetic circuits can generate a detectable signal in response to the presence of a target molecule.
The incorporation of synthetic biology into wearables could open up new possibilities for noninvasive monitoring of physiological status, disease states, and pathogen or toxin exposure. Synthetic circuits, on the other hand, require the presence of the living, created bacteria to function, which has limited their use in wearables.
The study describes lightweight, flexible substrates and fabrics that have been functionalized using freeze-dried, cell-free synthetic circuits that detect metabolites, chemicals, and pathogen nucleic acid signatures, as well as CRISPR-based tools. The wearable devices detect the presence of certain molecular targets via colorimetric changes or an optical fiber network that monitors fluorescent and luminescent outputs after rehydration from aqueous exposure events. Nucleic acid detection limits are comparable to those of modern laboratory procedures such as quantitative PCR. The findings show the development of a face mask with a lyophilized CRISPR sensor for wearable, noninvasive detection of SARS-CoV-2 at room temperature in 90 minutes with no human interaction other than a button click.
“Other groups have created wearables that can sense biomolecules, but those techniques have all required putting living cells into the wearable itself as if the user were wearing a tiny aquarium. If that aquarium ever broke, then the engineered bugs could leak out onto the wearer, and nobody likes that idea,” said Nguyen.
“We wanted to contribute to the global effort to fight the virus, and we came up with the idea of integrating wFDCF into face masks to detect SARS-CoV-2. The entire project was done under quarantine or strict social distancing starting in May 2020. We worked hard, sometimes bringing non-biological equipment home and assembling devices manually. It was definitely different from the usual lab infrastructure we’re used to working under, but everything we did has helped us ensure that the sensors would work in real-world pandemic conditions,” said co-first author Luis Soenksen, Ph.D., a Postdoctoral Fellow at the Wyss Institute.
“This work shows that our freeze-dried, cell-free synthetic biology technology can be extended to wearables and harnessed for novel diagnostic applications, including the development of a face mask diagnostic. I am particularly proud of how our team came together during the pandemic to create deployable solutions for addressing some of the world’s testing challenges,” said Collins, Ph.D., who is also the Termeer Professor of Medical Engineering & Science at MIT.
The wFDCF face mask is the first SARS-CoV-2 nucleic acid test that achieves high accuracy rates comparable to existing gold standard RT-PCR tests while working at room temperature, removing the requirement for heating or cooling instruments and allowing quick screening of patient samples outside of labs.
The face mask diagnostic is the icing on the cake for the researchers, who had to overcome various obstacles to make their technology genuinely wearable, including trapping liquid droplets within a flexible, unobtrusive device and preventing evaporation. Electronic components are absent from the face mask diagnostic for ease of manufacture and low cost, but incorporating more permanent parts into the system opens up a wide range of other prospective applications.
The researchers show in their paper that a network of fiber optic cables can be linked into their wFCDF technology to detect fluorescent light created by biological reactions, suggesting a high level of accuracy in detecting the target molecule. This digital signal can be supplied to a smartphone app, which allows the wearer to track their exposure to a wide range of chemicals.
“This technology could be incorporated into lab coats for scientists working with hazardous materials or pathogens, scrubs for doctors and nurses, or the uniforms of first responders and military personnel who could be exposed to dangerous pathogens or toxins, such as nerve gas,” said co-author Nina Donghia, a Staff Scientist at the Wyss Institute.
The team is actively seeking manufacturing partners that are interested in assisting in the mass manufacture of the COVID-19 face mask diagnostic, as well as for detecting additional biological and environmental threats.
“This team’s ingenuity and dedication to creating a useful tool to combat a deadly pandemic while working under unprecedented conditions is impressive in and of itself. But even more impressive is that these wearable biosensors can be applied to a wide variety of health threats beyond SARS-CoV-2, and we at the Wyss Institute are eager to collaborate with commercial manufacturers to realize that potential,” said Don Ingber, M.D., Ph.D., the Wyss Institute’s Founding Director.
This research was supported by the Defense Threat Reduction Agency under grant HDTRA1-14-1-0006, the Paul G. Allen Frontiers Group, the Wyss Institute for Biologically Inspired Engineering, Harvard University, Johnson & Johnson through the J&J Lab Coat of the Future QuickFire Challenge award, CONACyT grant 342369 / 408970, and MIT-692 TATA Center fellowship 2748460.