They might look like simple pieces of plastic, but when they’re filled with cells, they take on a life of their own, modeling the way whole organs work for drug discovery and disease research. These synthetic organs on chips could one day replace some animal studies and speed understanding of disease and wellness.
The team, at Boston Childrens’ Hospital and Harvard’s Wyss Institute, is currently working on 10 different organs. Each of the chips is built using techniques like those common in the semiconductor industry. "This allows us to create features and structures that we can control at the size scale in which cells live, and also apply physiological fluid flows and mechanical forces," Donald Ingber, one of the researchers, explained in a blog post. "We have precise control over where cells live in the device and what they experience."
For example, the lung on a chip mimics the human lung’s response to infectious agents, airborne particles, and toxins in a way that’s truer to real life than standard cell testing in a lab dish. The lung chip, which is a clear piece of plastic about the size of a USB stick, has a central channel split into two parts by a porous membrane. One side contains human lung cells of the type that are found in air sacs; the other side holds lung cells that move blood through the capillaries. A combination of special pumps subject the cells to the sensations of continuous blood flow and rhythmic breathing by moving culture medium through the blood vessel channel, which makes the cells respond the way they would inside the body.
Last year, the researchers used the chip to mimic pulmonary edema and show how different treatments impacted the condition.
A gut on a chip models the complex environment of the human gut—including its microbial inhabitants. The researchers plan to study the relationship between the microbiome and human intestinal disease processes.
The next step is to string all the chips together, the researchers say, creating an entire body. DARPA has put $37 million into the effort. Why might DARPA be interested? "Several U.S. agencies are working together to help safeguard Americans from deliberate chemical, biological, radiological, and nuclear threats, as well as from emerging infectious diseases, by drastically accelerating the drug development process," says the press release.
The researchers say the chips could help drive innovation in a number of ways. Pharmaceutical companies are finding they have a high rate of failure with new products, because animal models—even chimeric ones with human-like systems—aren’t the same as human models. The chips would better mimic the human situation, say the researchers, allowing them to study illnesses like Crohn’s or asthma with a more whole-body view. They also would save time and money for research.