Lord Dowding Fund for humane research


National Antivisection Society

Animal free model of human airways can prevent animal tests for toxicity of e-cigarettes

29 May 2019


The development of an innovative new model of the human airways, to be used for testing the toxicity of e-cigarettes, is being funded by the Lord Dowding Fund, a department of Animal Defenders International Foundation. Announced ahead of World No Tobacco Day on 31 May 2019, the method will use human cells instead of live animals and will not employ any animal products. Foetal calf serum (FCS) is commonly used by researchers as the medium to grow human cell lines.

It is hoped the new test method will help prevent experiments on animals as questions are raised about the long-term effects of e-cigarette use (vaping). Such experiments are already underway in the USA and commonly involve forcing animals, some who are pregnant, to inhale vapour daily for weeks and sometimes over months while confined in boxes or restrained in tubes. After the tests, the animals are killed, and their tissues analysed.

Such tests have not taken place in the UK to date, however, new regulations will require e-cigarettes to be tested as medicinal products, should a manufacturer register them as such as an aid to help people quit smoking, which could increase the likelihood of animal testing.

Jan Creamer, President of Animal Defenders International said: “Public outcry at smoking experiments led to them being ended, therefore the public, including those who vape, would be concerned to see animal tests for an alternative smoking product. We are excited to be funding the development of this innovative project which will save animals and provide accurate human-based data. It will also advance the way human cell lines can be maintained which could have far reaching effects.”

Due to species differences, animal models are an unreliable way of testing the toxicity of substances such as e-cigarette extracts in humans. Developing animal-free models of human airways provides a cruelty-free, more ethically acceptable and more scientifically reproducible model for testing for possible harmful effects of e-cigarettes. It is particularly important that we understand potential health risks of these products, as they are used more frequently as aids to stop or reduce tobacco smoking.

The multidisciplinary project led by Dr Laura Leslie at Aston University in the UK brings together researchers from the fields of engineering, biology and health sciences, and will help train future scientists in animal free methods.

Dr Laura Leslie at Aston University said: “The use of foetal calf serum to grow human cells, although currently standard practice, can present scientific challenges. By developing an entirely animal free model, we hope to set the standard for a completely human relevant method for investigating the effects of e-cigarettes on the human airways, an area where there is currently a lack of information.”

To grow the human tissue model, cells are submerged as they would be in the body in so-called “growth medium”, which needs to be supplemented with a mixture of hormones, proteins, and other vital factors, to provide the cells with all the nutrients they need to grow and function.

A commonly used supplement is foetal calf serum, also known as FCS, which is obtained from the foetuses of cows who are pregnant at slaughter. FCS is thought to be taken, without anaesthetic, straight from the heart of the calf foetus using a needle, with the potential to cause pain and suffering. Aside from the clear ethical concerns, the use of FCS has scientific implications too. Although cells grow in FCS, their function, such as cell spreading and attachment, can be affected and this may influence the experimental outcome.

The unique model, being developed by Dr Leslie’s team, uses multiple cell types submerged in medium without FCS. The cells are tested, and the results compared to previous data from cells grown with FCS. The next stage is to test the cells under a “dynamic flow system” which more accurately mimics the environment in human airways, with nutrients continuously delivered to the cells and waste products carried away. The dynamic model will then be used to see how the cells respond to e-cigarette exposure, as the researchers’ aim to provide an animal free opportunity for regulatory toxicity testing.

Donate here to support this project and the work of ADI Foundations’ Lord Dowding Fund

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