Abstract
Introduction
Teaching students at university level about alternative methods and the Three Rs (Replacement, Reduction and Refinement) 1 is essential, in order to promote the widest possible implementation of non-animal models in future society. This article describes the experience from the Global Master’s programme in toxicology 2 at the Karolinska Institutet (KI) in Sweden (‘ToxMaster’).
The ToxMaster programme
The students following this international programme have various educational backgrounds, with bachelor degrees in biology, chemistry, biomedicine or other fields from the natural or medical sciences. At the start of the programme, their knowledge and experience in the Three Rs differ widely. Many students have been engaged in non-animal alternative methods from the very start and might even have applied to the ToxMaster programme specifically to learn more about the Three Rs.
The Global Master’s programme in toxicology at KI was one of the first toxicology programmes worldwide when it started in 1976. The programme focuses on toxicology from a human health perspective, which means studying topics associated with the safety of pharmaceuticals, consumer products and chemical products having different uses, for example, cosmetics, pesticides, food additives, as well as environmental contaminants. The curriculum of the KI ToxMaster programme covers many different methods and approaches — as well as applications — that are used in toxicology and risk/safety assessment, including basic and applied research methods, regulatory toxicity testing and health risk assessment. Since 2010, the ToxMaster programme has been an international programme and, as such, it attracts students from all over the world. More than 200 students from over 30 countries have up to now participated in the programme.
After graduating from this 2-year programme, the students continue either towards a career in research, with its associated doctoral-level education to attain a PhD degree, or towards a professional career within a regulatory agency (such as one of the various food or chemical agencies), or within the pharmaceutical or chemical industry. In recent years, more and more toxicologists are also being employed in consultancy companies that support small and medium-sized enterprises in their fulfilment of the ever-increasing regulatory requirements.
The Three Rs in toxicology
For a toxicologist, it is of vital importance to have access to relevant and reliable data, and methods to evaluate toxicity and to predict potential health effects from exposure to various chemical substances. Such data are also crucial as a basis for estimating safe exposure levels, such as limit values or acceptable daily intakes.
Many different methods and models are currently available and are widely used, including computational methods (in silico), cell-based systems (in vitro) and animal (in vivo) models, as well as studies in humans. All have their individual strengths and limitations when it comes to relevance and usefulness for toxicity evaluation and risk/safety assessment.
Traditionally, experimental animals, mainly rats and mice, have been used as models to predict toxicity in humans. Today, there are rapid advances in the development of non-animal methods and new approach methodologies (NAMs), and there is a general political aim to reduce animal testing for regulatory purposes. This way of promoting the Three Rs often goes in line with increased scientific data quality.
Animal studies are still the main requirement for regulatory toxicity testing in many areas, including the testing of pharmaceuticals, pesticides and industrial chemicals. These studies must be performed according to high quality standards, such as the Organisation for Economic Co-operation and Development (OECD) Test Guidelines. However, in the EU regulation for cosmetics, there is a ban on animal testing, and in the EU REACH regulation, testing for local toxicity and skin sensitisation must always start with non-animal methods. Besides the application of non-animal methods for toxicity testing, the development of new risk assessment procedures based on non-animal data is also required.
Human data are used if available, but such studies are only required for drug development, not for other regulatory areas. Also, a primary focus in regulatory safety assessment is to be able to predict toxicity before humans are exposed to a particular chemical — and this therefore limits the role of human data.
Teaching about alternative methods and the Three Rs on the ToxMaster programme
When teaching about the Three Rs and alternative methods on the KI ToxMaster programme, it is important that they are put firmly in the context of the different requirements of the various different regulations. For almost 20 years, the ToxMaster programme has collaborated with the European Commission Joint Research Centre (JRC) and the EU Reference Laboratory for alternatives to animal testing (EURL ECVAM) to help achieve this goal. Through regular visits to JRC and EURL ECVAM more than 200 students from all over the world have learnt about the latest developments in non-animal approaches, as well as about the validation and regulatory acceptance of such methods.
Different aspects of replacement, reduction and refinement are included in the different courses of the ToxMaster programme, leading to a progression in all Three Rs teaching throughout the programme. Students learn the basic facts, approaches and applications, as well as the current EU legislation, both in theory and practice. Courses include discussions about all Three Rs and students’ reflection on the Three Rs in relation to regulatory toxicity testing in rats, as well as in relation to their own Master thesis project.
Compared to the situation when the ToxMaster programme started in 1976, there has since been substantial development in all areas of the Three Rs. Previously, toxicology was much more dependent on animal data than it is today. Even though animal studies were regulated according to animal welfare legislation, refinement was, to a high degree, up to individuals to improve their methods. Also, there was a clear polarisation at that time between the view of those using experimental animals and of those that were against animal testing.
The next-generation toxicologists of today’s Global Master’s programme in toxicology at Karolinska Institutet openly discuss and debate about all Three Rs. They all agree on the direction of the way forward. What differs only is their own personal view on when society will rely solely on non-animal methods in science and regulation.
Conclusions
To conclude, there has been substantial development of both the extent and quality of the Three Rs teaching on the KI ToxMaster programme during the last decades. The concept of Three Rs training now runs like a track throughout the programme, with a clear progression. Open discussions among students are of vital importance for their learning.
We believe that it is very important to include all Three Rs in the teaching of students, to present an overall perspective on both animal and non-animal methods, as well as to prevent any polarisation between researchers and toxicologists who are using different methods.
Important contributing factors to the success of the KI ToxMaster programme are the knowledgeable and engaged teachers that we have onboard, as well as the regular and inspiring visits to the JRC and EURL ECVAM. Of course, it is the engaged students who will become the next-generation toxicologists (see Figure 1) and take forward their knowledge, skills and attitudes into the wider scientific community! It is really fantastic to follow the students’ development in their proficiency in naturally discussing all Three Rs principles in relation to almost every topic! Next-generation toxicologists, 2021. Photo of the ToxMaster students, 2019–2021. [Photo by Annika Hanberg].