Whole organs on a chip coming to diagnostic centers near you

Multi Organ-on-a-chip

So-called organs-on-a-chip have become an important way to test the effects of chemicals or radiation on different kinds of cells. The military, in particular, has been interested to use them to study how poisonous agents like ricin, botulinum toxin, or anthrax attack different organs. Ideally, there would be a way to integrate individual subunits into a single body-on-a-chip where all the different elements could interact in a more realistic way.

Researchers in the field (and the various funding bodies that support them), got together last week at a meeting of the American Society for Microbiology in DC to discuss how this might best be done. Several concepts have previously been fleshed out for devices thatmimic the biological particulars of everything from liver, gut, or lung, to more refined tissues like the brain. The key now is to integrate some of the other intangibles that make the body work as a whole — the more nebulously distributed organs like the vasculature, skeleton, or skin.

Donald Ingber, an FDA-supported researcher from Harvard’s Wyss Institute, has developed a “bone marrow on a chip” device. Bone marrow, among other things, is where blood cells get made. The effects of radiation, and many toxic chemicals, are most acutely absorbed there. These kinds of nasties often lead to the “liquid tumor” class of cancers — the leukemias and lymphomas where out of control cells proliferate and then circulate as single entities in the blood or lymph. Many viruses which go on to infect individual organs to various degrees, hang out in white blood cell reservoirs where they can continually gain infective passage to the entire body.

A recent article mentioned that the EPA is planning to announce a new $18 million war chest to combine livers on chips with other devices that simulate fetal membranes, mammary glands, and developing limbs. These regions have been shown to be particularly susceptible to environmental pollutants like dioxin and bisphenol A. Like many harmful chemicals, their metabolite products generated by the action of various enzymatic systems of the liver are often what does the real damage.

Sometimes the fastest way to find out what chemical, bacteria, virus could be causing your problem is not to try to positively ID the invader but rather to analyse their metabolic effects on the body. As it happens, different organs have come to exert their wills upon each other in many idiosyncratic ways. Gross physiologic observables like heart rate, blood pressure, and blood composition are in part controlled by rare peptides or hormones often made by just a single organ. In quirky yet predictable feats of evolution, via myriad migrations from salt water to fresh water and back, ultimately through mud to air, our lungs, kidneys and guts have had their mutual allegiances repurposed and honed for the benefit of the whole.

The plan for the integrated organ on a chip is to have working devices in researchers hands in five years. On the other diagnostic front, there are new gene or antigen array chips that can potentially sequence or otherwise capture any villian as fast as you can feel it. No doubt both approaches with by of value in keeping our military, and hopefully our civilians healthy.