Rethinking Healthcare

Gut-on-a-chip could replace animals in drug testing

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The microdevice is lined by living human cells, mimicking the structure, physiology, and mechanical behavior of our 25-foot long intestines. It even supports the growth of live microbes.

About 25 feet of intestines are folded and curled up inside our bodies. Harvard bioengineers now say they’ve created a tiny device that mimics all the essential functions of our intestines.

The gut-on-a-chip (pictured) microdevice is lined by living human cells that recreates the 3D structure, physiology, and mechanical behavior of our guts. It even supports the growth of live microbes.

This silicon polymer chip the size of a flash drive could help researchers learn more about intestinal disorders, such as Crohn's disease and ulcerative colitis, and evaluate the safety and usefulness of potential treatments and probiotics.

  • Inside the central chamber, there’s a single layer of human intestinal cells growing on a flexible, porous membrane – a recreation of the intestinal barrier that nutrients pass through.
  • The membrane attaches to side walls that can stretch and recoil with an attached vacuum controller – which mimics the wave-like (peristaltic) motions that help move food along the digestive tract.
  • The design also captures the intestinal tissue-tissue interface, allowing fluids to flow above and below the intestinal cell layer – mimicking the hollow spaces in our guts on one side of the device and the flow of blood through capillary vessels on the other.
  • Common intestinal microbes can also be grown and sustained on the surface of the intestinal cells.

"Because the models most often available to us today do not recapitulate human disease, we can't fully understand the mechanisms behind many intestinal disorders, which means that the drugs and therapies we validate in animal models often fail to be effective when tested in humans," study research Donald Ingber of Harvard’s Wyss Institute says in a news release.

Watch a video describing organs-on-a-chip. What if we could test drugs without animal models, they ask.

This microfluidic platform was first reported in 2010 by Harvard researchers with lung-on-a-chip. That same year saw a heart-lung micromachine for inhaled drugs. There’re kidneys and bone marrow too. Last year, Wyss researchers were awarded a grant from DARPA to develop a spleen-on-a-chip to treat sepsis, a commonly fatal bloodstream infection.

The work was published in Lab on a Chip earlier this month.

[Via IEEE Spectrum, Wyss news]

Image: Wyss Institute for Biologically Inspired Engineering

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Janet Fang

Contributing Editor

Janet Fang has written for Nature, Discover and the Point Reyes Light. She is currently a lab technician at Lamont-Doherty Earth Observatory. She holds degrees from the University of California, Berkeley and Columbia University. She is based in New York. Follow her on Twitter. Disclosure