Washington: In a first, the US military and civilian science agencies are working on a project to develop miniature human organs on plastic chips to test the fallout of deadly radiation on people.
Each year, the US government spends millions of dollars stockpiling counter-measures for potential biological, chemical and radiological warfare agents.
For ethical reasons, many of these treatments have never been tested on humans.
"It is unethical to expose humans to the kind of radiation that you would see in a disaster like Fukushima, but you need to be prepared," said Donald Ingber, bio-engineer at Harvard University's Wyss Institute in Boston, Massachusetts.
With support from the US Food and Drug Administration, he is adapting his "bone marrow on a chip" to study the effects of harmful radiation and experimental remedies, the scientific journal Nature reported.
The researchers hope that these complex three-dimensional (3D) systems will mimic human physiology better than do cells grown in a dish, or even animals.
A common way to form a model organ is to seed cells into channels in a small plastic chip and then feed them with nutrient-rich fluid that flows through the system to mimic blood.
The devices can be used individually or connected to other types of organs-on-chips to approximate a biological system, or -- eventually -- perhaps an entire human body, the report added.
The US Environmental Protection Agency plans to announce a $18-million programme to link "livers on chips" with chips that simulate fetal membranes, mammary glands and developing limbs.
The aim is to study how environmental contaminants such as dioxin and bisphenol A alter metabolism in those organs once they have been processed by the liver.
"Researchers have already developed dozens of individual model organs; the next challenge is to hook them together with the eventual goal of forming an entire human body on a chip," said Kristin Fabre, programme manager at the National Centre for Advancing Translational Sciences (NCATS) in Bethesda, Maryland.
This would provide a more accurate picture of the effects of a drug, toxin or other agent on human physiology, the report concluded.