Development of 3D human tissue models for toxicological (DNA damage) testing.

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Much of the highly regarded work carried out in the DNA damage group at Swansea is based on the use of human cell models of differing tissue origin and possessing specific genetic modifications (e.g. related to metabolic activation, DNA repair). These models are robust tools for studying the mechanisms of DNA damage induction and the consequences of such DNA damage. However, it is becoming clear that more complex models mimicking human exposure scenarios are needed. Bearing in mind the moves to reduce the use of animals in human safety testing, the use of 3D human tissue models is gaining much attention. This is particularly true for the cosmetics industry where a worldwide marketing ban, introduced in 2009 through a European Directive has made it impossible to test cosmetic ingredients in animals.

Hence this application would allow the group at Swansea to gain significant knowledge from our partners at Unilever about the strengths and weaknesses of the various 3D tissue models. This would allow the development of in house models for toxicology testing through close partnering with experienced scientists at Unilever. Our colleagues at Unilever have a longstanding interest in developing 3D models (particularly skin) for cosmetics testing. We aim in this fellowship application to transfer that knowledge and skill base to Swansea, learn from external experts in the field about the latest developments in 3D models (skin initially) and carry out a proof of concept study to develop and use skin models to test DNA damage induction. We can then use our own significant experience in cellular DNA damage induction to compare the different cellular and tissue models to validate the tissue models for DNA damage detection.

We plan to develop a chromosome damage test (the micronucleus (MN) assay) for detecting DNA damage in intact 3D tissues. We will use commercially available 3D models (Epiderm) and also develop our own novel models. We have many years of experience with the MN assay in vitro, but in the case of the 3D models, the assay will require some modifications. Hence a secondary challenge (as well as developing suitable 3D models), is to validate the DNA damage detection in these tissues. We aim to use a recently purchased InCell Analyzer (GE Healthcare) to scan through the tissue sections (in Z-stacking mode) seeking out chromosomal fragments. After establishing the 3D models in Swansea, we will assess the ability of those models to detect DNA damage induced by 2-3 classic genotoxic agents. This will be a validation process and comparisons between this data and the cell model data already obtained by ourselves will provide interesting data on relative sensitivity of the systems. The validated models will then be available for scientists at both Swansea and SEAC to utilise.

The unique selling point of this application is the fact that this proposal builds on the close interactions between Swansea University and Unilever in the field of DNA damage that have been built up over the preceding years. Hence, there is a very strong collaboration already in existence which will increase the chances of success here enormously. This close interaction ensures that the goal of this proposal is shared by both partners providing the impetus necessary to drive the project forward to completion.