Texas A&M researches extreme flight conditions using 3D-printed lung models

When pilots climb to high altitudes or astronauts travel into Earth orbit, the lungs and circulatory system are exposed to significant stress. Conventional 2D cell cultures can represent these situations only to a limited extent. A research team at Texas A&M University is therefore using 3D bioprinting to create more realistic lung models and to specifically investigate their behavior under extreme conditions.

Led by Zhijian “ZJ” Pei and Hongmin Qin, the researchers print gel-like bioinks containing living lung cells layer by layer into three-dimensional structures. The resulting scaffolds reproduce the architecture of airway tissue much more accurately than flat cell layers.

“By investigating how 3D-bioprinted samples embedded with lung cells respond to physical stress, we’re advancing the fundamental principles of the effects of extreme environments on human biological systems”, said Dr. Zhijian “ZJ” Pei, Professor, Industrial & Systems EngineeringTexas A&M University College of Engineering.

“With our 3D approach, we can closely mimic native tissue and their microenvironments, enabling accurate studies of viability, proliferation and stress responses,” Qin said.

The focus is on physical stressors that play a role in aviation and spaceflight: elevated temperatures, pressure fluctuations, and oxygen deprivation. These factors can lead to fluid accumulation in the lungs, tissue damage, or functional impairments.

“Our findings shed light on how lung cells respond to physiological and mechanical stressors, including variations in pressure and temperature,” Qin said. “Potential applications could enhance safety protocols for pilots and astronauts in low-orbit conditions.”

At the same time, the team is addressing fundamental questions of bioprinting process control. Studies show that high extrusion pressures significantly reduce cell viability, while temperature loads up to 55 degrees Celsius increase oxidative stress and cell death. An optimized bioink with a 4:1 collagen-to-alginate ratio achieved cell viability of around 85 percent over six days in experiments.

“Even small adjustments in the bioprinting process can dramatically affect cell viability and proliferation,” Qin said. “By fine-tuning these parameters, we are laying the groundwork for future breakthroughs in tissue engineering.”

“We are bridging the gap between concept and applications that make a tangible difference,” Pei said.

In the long term, the researchers see the printed lung models as a platform for studying respiratory diseases and for drug testing. The project demonstrates how 3D bioprinting can be used not only for implantable tissues, but also as a precise tool for simulating extreme operating conditions—layer by layer at laboratory scale, before humans are exposed to the stress in the cockpit or in space.