For the good of humanity and medical research, Harvard scientists have invented a robot that smokes cigarettes.
Well, calling it a robot may be a bit of a stretch—it’s more of a lab instrument. But the device does puff on up to 10 cigarettes at a time, taking in the smoke and channeling it to a tiny chip lined with living cells from human lungs. This “lung-on-a-chip” can be used to study how lung cells react to smoke, in intimate detail and with a level of verisimilitude that animal studies can’t match.
The invention, announced yesterday by the Wyss Institute for Biologically Inspired Engineering, can be used for research on chronic obstructive pulmonary disease (COPD), the lung condition that includes both emphysema and chronic bronchitis. People with COPD find it harder and harder to breathe because the tiny airways in their lungs are damaged, typically from years of cigarette smoking. There’s no known cure, and doctors can’t repair the damage. More than 11 million people in the United States. have been diagnosed with COPD, and the worldwide toll is reckoned at 65 million.
Studying the effects of cigarette smoke on lung cells is a surprisingly tricky task. Culturing the cells in a Petri dish and wafting smoke over them doesn’t work well, because that setup can’t replicate the dynamic environment of a real lung where cells move with every breath. Testing in lab mice or rats is also problematic, because these rodents only breathe through their noses. That means researchers can fill a lab rat’s enclosure with smoke and let the animal passively take it in, but they can’t make the rat take a long deliberate drag.
The smoking machine lights its own cigarettes, then uses a “micro-respirator” to pull in and push out the smoky air in mimicry of the body’s rhythmic inhales and exhales. To represent different types of smoking behavior, researchers can program the machine to puff faster or slower, and to take deep drags or shallow breaths.
The smoke flows into the lung-on-chip [photo below], a small plastic doodad with a miniscule channel that’s lined with the epithelial cells found in the airways of human lungs. These cells can be taken from various sources. In the first published experiment from the Wyss Institute team, led by founding director Donald Ingber, scientists took lung cells from both healthy people and COPD patients to see cigarette smoke’s impact on each set. The technology may enable discoveries about the pathology of COPD by giving scientists a better look at what goes wrong in those lung cells, and it can also serve as a platform to test new drugs.
Photo: Wyss Institute/Harvard University
E-cigarettes can also be studied in the smoking machine—which may be a real advance for research, since lung cells in a Petri dish and lab mice can’t be convinced to vape. There’s considerable debate over the health effects of e-cigarettes, so investigators will likely be grateful for a new research tool.
The new invention builds on prior work at the Wyss Institute, which is serving up more organs-on-chips than a manic French chef. Just earlier this week the team unveiled a 3D-printed heart-on-a-chip with built-in sensors to measure the strength of contraction in beating heart cells. All these components are part of a grand plan to build a “human-on-a-chip,” which will link 10 organ-chips together to mimic the whole human body.
Here’s the video the institute put out to more fully explain why they built a smoking machine and how it works.<
Eliza Strickland is a senior editor at IEEE Spectrum, where she covers AI, biomedical engineering, and other topics. She holds a master’s degree in journalism from Columbia University.