'Tissue chips' could replace animal studies, UW-Madison researchers say

Drugs that seem safe in animal studies are sometimes found to be harmful in humans.

The health effects of many chemicals on the market in products such as cosmetics, food additives and industrial and household cleaners arent fully known.

Theres a huge need to come up with better ways of testing compounds to see if theyre toxic, said James Thomson, the UW-Madison stem cell pioneer.

Thomson, who first grew human embryonic stem cells in a lab in 1998 and co-discovered a way to reprogram mature cells to their embryonic state in 2007, is working with researchers across campus on a new quest.

Theyre creating tissue chips clusters of interacting cells that mimic specific organs, such as a model of a developing brain. Using stem cells, miniature scaffolds and sophisticated computer programs, theyre crafting prototypes that could someday replace animal testing for drugs and serve as screening tools for environmental toxins.

About 80 percent of experimental drugs fail in human clinical trials because they are unsafe or ineffective, with some 30 percent found to be toxic in people despite promising results in animal studies, according to the National Institutes of Health.

Largely because of the expensive failures, it costs more than $1 billion to bring each successful drug to market, the NIH says.

Meanwhile, the European Union has started requiring toxicity testing of widely used chemicals. The U.S. Environmental Protection Agency launched a program to better screen the tens of thousands of chemicals currently in use.

Through a U.S. effort spanning multiple federal agencies, UW-Madison researchers have received $9 million from the NIH and applied for EPA funding to develop better drug and chemical testing methods.

In the NIH-funded work, the UW-Madison group is focusing on brain cells. Ten other universities are designing other kinds of tissue chips: Harvard scientists are working on a heart-lung model, a University of California, Berkeley team is working on the liver, and University of Washington researchers are concentrating on the kidney.

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'Tissue chips' could replace animal studies, UW-Madison researchers say