Concern over the spread of infections and diseases has seen increased public awareness in recent years, thanks largely to the coronavirus pandemic. In many instances, people’s fears are completely justified, as they have experienced relatives and loved ones placed on ventilators, or recieving other serious treatments.
While respiratory illnesses can be painful, scary, and even life-threatening, new research has found a positive side to people’s increased concerns. Specifically researchers from Harvard University have found that, using lungs-on-a-chip, the act of breathing can actually help to fight diseases, showcasing the unique disease-battling capabilities of the human body.
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Background: How Your Lungs Work
Lungs have a unique design that allows them to do their job rather efficiently. Inside the lungs are millions of alveoli, tiny air sacs full of capillaries that perform gas exchange. When an individual breathes, their inhaled gasses are exchanged with exhaled gasses using a thin blood-air barrier. This is why we exhale carbon dioxide and inhale oxygen. According to some studies, an average person takes approximately 600 million breaths over the course of their life. For the researchers at Harvard University, they hoped to unlock something new in studying the process of breathing.
Analysis: Breathing Biotechnology
The researchers first developed a lungs-on-a-chip system to further study breathing. Lungs-on-a-chip is a part of the overall field of biotechnology known as organs-on-chips. Whether it be a brain, heart, ear, eye, or something else, an organ-on-a-chip combines biology with technology, as cell cultures are grown into mini-organs no bigger than a USB memory stick in many cases. Organs-on-a-chip allows for scientists to better study biological responses without needing human test subjects, saving significant time and money for many biotechnology companies.
For the Harvard scientists, they simulated human lung cells by using two different chip systems. The upper chip represented the alveolar cells while the lower chip represented lung blood vessel cells. This two-chip system allowed the researchers to track the movement of gasses from alveoli to blood vessels. To test these chips, the researchers infected the “lungs” with the H3N2 influenza virus. After infection, the researchers saw the breakdown of connections between cells as well as the activation of cell repair processes. The “lungs” also expressed higher levels of immune cells. From their findings, the scientists saw that the lungs were working to fight the infection. In comparing chip systems that performed breathing motions versus those that didn’t, those that “breathed” showed 50% less viral mRNA in the lung channels and significantly less inflammation. According to co-first author Professor Longlong Si: “This was our most unexpected finding-that mechanical stresses alone can generate an innate response in the lung.”
Outlook: Modeling Lung Infections
With attention still on the coronavirus, understanding the mechanics of lung infections is important. “This research demonstrates the importance of breathing motions for human lung function, including immune responses to infection,” explained co-first author Dr. Haiqing Bai of Harvard University. “It shows our Human Alveolus Chip can be used to model these responses in the deep portions to the lung, where infections are often more severe and lead to hospitalization and death.” Having a lung-on-a-chip model system can not only track infections but also help drug companies test their drugs to ensure they actually help to reduce infection and inflammation.
Kenna Castleberry is a staff writer at the Debrief and the Science Communicator at JILA (a partnership between the University of Colorado Boulder and NIST). She focuses on deep tech, the metaverse, and quantum technology. You can find more of her work at her website: kennacastleberry.com/