The future is the size of a child’s plastic toy brick, and doesn’t weigh much more than that. It’s being produced in an old industrial facility in Berlin’s neighborhood of Wedding next to a moving company and above a language school. A medical revolution is brewing on the building’s third story—the human-on-a-chip.

Until now, the pathway to developing effective medications has been arduous and expensive. On average, medical compounds require ten to thirteen years to reach market maturity, and around 80 percent fail to obtain approval along the way. The main problem: the imprecision of animal testing. Something that works for a small animal isn’t ne­cessarily suitable for larger animals or even for humans. A drug’s unsuitability often doesn’t become apparent until very late in the process, usually only during tests on volunteers. Then it’s back to the drawing board. Pharmaceutical companies invest an average of 800 million euros per medication.

In Berlin, researchers at TissUse are working on developing an alternative. The company “recreates” human organs. The small-format organ models are cultivated on a glass slide, known as a chip. A control unit supplies “circulation” to the artificial mini organism via vacuum pumps, which allow the functioning of the lungs, liver, skin, intestines or other organs to be simulated. Biotechnicians inject the medication and take samples, just as they would in a conventional laboratory. According to the manufacturer, this organ-on-a-chip technology is on the verge of being able to reliably mimic the complexity of human metabolism. An initial study on tumors in cooperation with Bayer looks promising so far.

This makes TissUse Director of Business Development Dr. Reyk Horland optimistic: he estimates that 60 percent of all animal testing could become superfluous in the future with the help of this chip technology. Even initial tests on humans may some day be replaced by chip testing. “It would mean that healthy volunteers would no longer have to take the risk of unanticipated side effects,” Horland says.

The researchers are already pursuing their next goal—they want to develop a central nervous system that can, for instance, simulate muscle contractions. However, the technology is reaching its limits with the nervous system. Just as it is unable to simulate bone fractures, it also cannot completely depict the human brain. So the chip will never be able to feel and think.

Instead, the chips could become the basis for individualized medicine. Until now medicine has often acted one-dimensionally, its main model being a Western European male. Asians react differently to medications, as do people of African heritage. Not to mention women, whose hormone balances are so complex that they are usually excluded from studies altogether. The human-on-a-chip could enable more precise research. In the future, a person’s own stem cells could be tested to see how they react to particular doses of medications. A pill with a personal fingerprint is on the horizon.