The field of bioengineering, or the use and study of artificial tissues and organs, has recently gained new insight into artificial organs due to a study which was conducted by a team of researchers at Princeton University. The researchers studied the design and development of a reptilian lung which revealed the physical principles used to build the organ.
The study is the first to analyze the way a reptile’s lung develops which could mean there are shortcomings in the research; however, for being the first of its kind, it offers novel information for bioengineers.
The revelations from the research could be exploited to advance the engineering of artificial tissues which can be used to restore, maintain, or improve damaged tissues or whole organs. These tissues can be used for skin, cartilage, heart and bone. The conclusions of this study may even help improve the success of skin graft surgeries.
The organizer of the study, Michael Palmer, a doctor of chemical and biological engineering, did years of preliminary research before beginning the study as a graduate student. He looked at many different species, including alligators (no fun to handle, apparently) and green anoles (they refused to breed) before landing on brown anoles.
“We were curious if we could learn anything about the basics of lung development from studying such a simple lung,” Palmer told the university’s newspaper.
In late 2019 Palmer and a colleague captured brown anoles in north Florida before driving them back to Princeton’s campus. From there, the university’s veterinarians and other staff established a facility for the anoles.
“Our group is really interested in understanding lung development for engineering purposes,” Celeste Nelson, the Wilke Family Professor in Bioengineering and the study’s principal investigator, told Princeton’s newspaper. “If we understand how lungs build themselves, then perhaps we can take advantage of the mechanisms mother nature uses to regenerate or engineer tissues.”
The team studied the brown anole lizard to see if the lung formation, reminiscent of
a mesh stress ball in action, could be exploited to make human skin tissues outside the living body, or ex vivo.
Unlike human lungs that develop over months and years, the brown anole lung develops within days - going from a flat structure to a blown-up balloon in two days. The team observed the lizard’s development and built a working replica using a computational model, fabricated membrane and 3D printed muscle cells - these cells are similar to what you would see in a living organ.
While the team did meet technical barriers that limited the prototype’s realistic appearance, the end product came very close to mimicking the same detail of the living organ that Palmer had observed.
The replica came close to mirroring the lizard’s lung complexity, too. The observations and prototype combined could offer up a new model for advanced biotechnology designs due to the speed of the lung growth and how they leverage simple mechanical processes.
“Different organisms have different organ structures, and that’s beautiful, and we can learn a lot from it,” Nelson told Earth.com. “If we appreciate that there’s a lot of biodiversity that we can’t see, and we try to take advantage of it, then we as engineers will have more tools to tackle some of the major challenges that face society.”
According to Princeton’s website, the team’s research paper “Stress ball morphogenesis: How the lizard builds its lung” was supported in part by funding from the National Institutes of Health, the National Science Foundation, the Eric and Wendy Schmidt Transformative Technology Fund and the Howard Hughes Medical Institute. Additional authors include Bryan A. Nerger, Katharine Goodwin, Sandra B. Lemke, Pavithran T. Ravindran, and Jared E. Toettcher, associate professor of molecular biology.
Check out these links to learn more about lizard lungs and their hand in bioengineering:
Comments