The days when chips were solely used to allow a computer to calculate, are gone. Today, they are also being used as a breeding ground for biological cells. They are kept alive in liquid compartments. High-resolution microscopes monitor everything that happens there. The ultimate objective is to simulate the human body, in order to test medicine or to determine the reaction to poisonous substances.
All of this is still science fiction. Even imitating organs on a chip is still in the future, says Jos Kleinjans, professor of Environmental Health Science. “At the moment European consortiums of businesses and universities are carrying out experiments using traditional petri dishes with various organ cells that interact with each other through small tubes. In doing so they are trying to imitate a biological system that approximates a fully functional human being.”
Such an imitation is of course limited, says Kleinjans. “Complicated matters such as hormone regulation are still beyond us. Nevertheless, I am optimistic about the European experiments. They provide hope for my field of toxicology. It would enable us – better than we can do now – to determine which substances cause damage in which organs. Parallel to this development, there are various programmes working on embryonic stem cells. These cells are well suited for this purpose, because they can grow into every type of cell and therefore also into every organ cell.”
For the time being, most research is done in petri dishes with a single type of organ cell. Kleinjans and his group work together with the university hospital’s department of surgery. “We regularly receive patients’ living cells from the surgeons, cancer cells but also healthy tissue. We grow, for example, liver cells and see how they react to certain substances.”
The simulations may not be perfect, but they predict more accurately what happens in a human being than in animal models, says Kleinjans. “I know of animal tests in which rats were injected with a carcinogenic substance for two years, while the predictive value amounts to no more than 60 per cent. Our cell models reach 85 per cent.”