The first organ chips are set to be introduced into the market. The chips will reduce the use of laboratory animal and speed up drug testing. In a recently opened laboratory just north of London, an experiment is under way to discover how the liver will respond to a new drug. Normally such a test would be carried out on liver cells cultured in rows of dishes or—as regulators require before approving a drug for clinical trial—in animals such as rats or dogs. But this experiment uses a small device about the size of a smartphone. It contains a miniature liver made from human cells and promises more reliable results. It is one of the first commercial versions of what bioengineers call an organ-on-a-chip.
The liver chip, named Quantum-B, was made by CN Bio, a firm spun out of the University of Oxford and now based in Welwyn Garden City. Quantum-B is designed to help researchers find a cure for hepatitis B, a viral infection of the liver. Other groups coming up with miniature organs include, in America, the Wyss Institute at Harvard University, whose devices include a lung-on-a-chip (pictured above), and the University of California, Berkeley, which has a heart-on-a-chip. Chips replicating the kidney, intestine, muscle, fat, bone and skin are also being developed.
Subject to regulators, such devices have the potential to slash the use of laboratory animals in drug testing. Animals are not necessarily good analogues for humans because of fundamental differences in biology. Testing on tissue in a dish can likewise prove unreliable because its cells often stop working. The more realistic data promised by organs-on-a-chip could accelerate drug development and allow researchers to carry out experiments too risky for human volunteers.
By linking different chips together, researchers can study how reactions in one organ affect another. A drug that produces beneficial results in treating heart disease, for instance, might be metabolized by the liver in a way that has toxic results. Indeed, with enough organs-on-a-chip, the twinkle in the eye of some scientists is that one day it might be possible to create the equivalent of a body-on-a-chip.
Most organ chips are made out of a synthetic material, such as a polymer. This might be transparent for viewing the cells through a microscope. The chips contain minute structures to which cultured human cells are attached. Given the right conditions, the cells will naturally arrange themselves as they would in the body and start to behave as if they were there. A technique called microfluidics is used to shuttle a blood-mimicking fluid along channels and tiny pipes, bringing sustenance to the cells. The Economist reports.