Organoids – miniature and simplified versions of a (human) organ – are a good example of new in-vitro approaches. They are grown in-vitro in three dimensions and allow researchers to study disease and treatments in the laboratory. An organoid grown from a biopsy of an individual patient can also help predict their response to new or existing drugs.

The use of animals in biomedical science is outdated and unnecessary. Human-relevant methods that offer a more effective and ethical approach are available. Broadly, these include in-vitro methods (test tube experiments performed with micro-organisms, tissues, whole cells or parts of cells), in-silico (computer-based) methods, studies with human volunteers, and simulators (based on virtual reality or physical models).

For example, aspirin was patented in 1900. It is safe for humans, but it would not be possible to market aspirin with the current methods and criteria for safety because it causes birth defects in mice, rats, guinea pigs, rabbits, cats, dogs, sheep and monkeys.

In fact, it may have held back the discovery of treatments and cures for humans because they did not work well in animals.

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Researchers in the Netherlands have shown how certain drugs can be tested for individual patients with cystic fibrosis. There are drugs for the treatment of this disease, but not all drugs work for all patients. So, the researchers took rectal biopsies from patients, grew them into mini-guts, and tested the available drugs for effectiveness. They showed that the drug responses observed in the mini-guts could be used to predict which cystic fibrosis patient would respond to which drug.

Chemical and biological substances, such as newly developed drugs, need to be tested to determine whether they are harmful to humans, animals or the environment. Currently, more than 100,000 chemicals available on the market have never been tested. Safety testing costs $US10 to $US20 million per product and takes several years. It is also difficult to obtain safety data for the 1000 new chemicals created every year. Computer programs and large databases can make testing of substances much faster and cheaper – and without using animals (although data obtained in the past from animals may be used).

The read-across method, for example, uses data from a chemical substance for which safety information is available, to make predictions for a similar substance about which not much is known.

The software builds a map on which similar chemicals are placed close to each other. It places new chemicals on the map, based on their structural similarity with chemicals already on the map. From this information, the computer can predict the potentially harmful health and environmental effects for the new chemicals. A group of researchers in the US combined several large databases with information about thousands of chemicals and used the read-across method to test its accuracy. They found that the new method was accurate 80 to 95 per cent of the time, compared to 50 to 70 per cent for animal tests.