Hurel’s test, which will not require any animal involvement, will mimic the interaction between the skin and the lymphatic system in response to a chemical. To build the chip, cells will be cultured to create an artificial lymph node–essentially tissue that can simulate a human immune-system response–a short distance away from an artificial skin construct made from cultured human cells. The artificial lymph node will be connected to the skin via a microfluidic system made of channels filled with a specially maintained chemical gradient.
To use the chip, the chemical product being tested would be put in contact with the artificial skin. If an allergic reaction occurred, dendritic cells would migrate toward the artificial lymph node in response to the chemical gradient, where they would stimulate the T cells.
Maish Yarmush, Hurel’s chief scientific advisor, says the company still has to determine how the test will be read. “We will need to monitor the response of the T cells,” Yarmush says. That could involve monitoring T cell proliferation or secreted molecules or both.
Determining how an allergic response will be measured is just one of many challenges for the team. “The microfluidic signaling piece has been developed,” Freedman says, “but we have to develop all [the] pieces and get them to work together.”
Regardless, Freedman said he expects to have a working prototype “complete and functional” by late 2011. The goal is to have the product on the market in time to meet the needs of cosmetics companies, which need a working animal substitute by 2013.
Sandusky notes that once complete, the Hurel test would also have one clear scientific advantage over animal tests: it would eliminate the issue of trying to extrapolate data gathered on animals to humans. “I’m very intrigued with Hurel’s approach,” says Sandusky. “We would love to see this thing really pan out.”