3D printing is transforming the world again -- Cornell researchers have used the technology to re-create conditions in a living intestine.

Realistic modeling has previously been a challenge for the study of intestinal biology. The new, 3D-printed microscale small intestine model mimics not only texture and structure, but also the fluid flow essential for digestion fluid flow that gut surface, or epithelial, cells require to grow, reproduce and function properly. It re-creates peristaltic fluid flow, which other models have failed to achieve.

Moreover, the system allows researchers to understand the dynamics of intestinal fluid flow. By re-creating peristalsis, cells were able to grow as they would in a living intestine. Proper flow encourages selective dying-off for cells along the tips of intestinal villi – which, in the absence of flow, become self-destroying. Accurate fluid flow also lets researchers study the dynamics of intestinal bacterial populations.

“The intestine is home to most of our immune system and it is also where all of our nutrients are absorbed, so to function as a human being or any multicellular animal, our gut is the centerpiece of our interactions with the outside world,” noted Professor John March, chair of the Department of Biological and Environmental Engineering. “The more we understand about how our guts work, the more we can develop therapies and gain insights into the evolution of human biology.”

March is the senior author of a paper describing the system, published in Scientific Reports.

As a synthetic, in vitro system, the new model is also able to control other parameters, including cell types, nutrient profiles and gaseous exchange. It is an “open” system, enabling access to chemical and physiological information.

And the best part -- thanks to 3D printing, almost any research group can now make a model like this one and tailor it to specific needs.