Microphysiological systems (MPS), the latest technological advances on alternatives to animal testing, are gradually being taken seriously by many scientists, which may end up using them and giving up the animal testing model. This umbrella term includes different types of high-tech devices, such as organoids, tumoroids, and organs-on-a-chip. Organoids are grown from human stem cells to create 3D tissue in a dish that imitates human organs. Tumoroids are similar devices, but they imitate cancer tumours. Organs-on-a-chip are plastic blocks lined with human stem cells and a circuit that stimulates how organs function.
Research has shown some tumoroids are about 80% predictive of how effective an anti-cancer drug will be, compared with the average 8 per cent accuracy rate in animal models. There are thousands of rare diseases and only 400 are being actively researched because there are no animal models that work for them. Abandoning the animal model concept and developing MPS solutions could allow scientists to start tackling all these diseases.
The first World Summit on MPS was held at the end of May 2022 in New Orleans, indicating how much this new field is growing. The USA FDA is already using its own labs to explore these technologies, and the US National Institutes of Health has been working for 10 years on tissue chips.
However, these alternatives tend to be used more for researching new drugs and treatments, rather than to perform safety tests that most jurisdictions only allow if animals are used. Only a few of the most advanced organoids have been used in safety testing, even if many could have been used. In this case, the obstacle seems to be more political than scientific, and therefore lobbying and campaigning would need to be stepped up to overcome this hurdle. Organisations such as Animal Free Research are leading in this type of campaigning.