XENOSENSE – developing a cell-free biosensor for toxicity testing, environmental monitoring, and risk assessment

Chemicals with environmentally harmful effects include both legacy substances that have been banned, such as PCBs and DDT, and new substances that are developed and used without adequate testing for toxicity. Such testing is traditionally done on animals, where crustaceans, fish and mice are exposed to new chemical substances in large numbers every year. Nevertheless, only a few of the approximately 350,000 substances on the market today have been thoroughly tested. At the same time, such use is ethically undesirable, and both the EU and the US are in the process of phasing out the use of animals in chemical testing. The toxicity of a substance usually starts with the binding to specific components of the cells of the exposed organism. These are often receptor proteins, a kind of antennas that receive signals that control important processes in the organism. When these processes are disturbed, various forms of toxicity occur. Some environmental pollutants disrupt hormonal balance and reproductive capacity. We call these endocrine disruptors. Others can interfere with growth, the immune system or the nervous system, depending on which receptors the compounds act on. The XENOSENSE project aims to develop a biosensor for pollutants based on knowledge about such receptors from different species. Through a unique link between research in environmental toxicology, modeling of receptor molecules, biotechnology and sensor technology, the project will develop a small microlaboratory, so-called Lab-on-a-Chip, that can signal whether a substance has one or more toxic properties, and can thus contribute to replacing the use of animals in chemical testing. The biosensor can also be used in environmental monitoring, to map contaminated areas in harbors and urban areas, or discharges from industry and sewage treatment plants. The project is coordinated by the University of Bergen with NTNU as research partner and STIM AS and Biosense Laboratories AS as industry partners.

In the XENOSENSE project, competencies in environmental toxicology, biotechnology, nanotechnology, and computational biology will converge to make radical progress towards ecotoxicology and environmental health research, and also towards regulatory toxicology and the 3Rs of animal research. A recent study suggested that the production and release of novel entities and chemicals has accelerated to a point where we have crossed a “planetary boundary,” threatening both human and environmental health. Around 350,000 different types of chemicals are currently on the international market, with production of existing and new chemicals set to substantially increase in the coming decades. The ultimate goal of 3R research has been the full replacement of animal testing with alternative methods. Yet, we are stille far away from reaching this goal, and our capacity to evaluate the risk of new and existing chemicals lags far behind the need. The core concept of the XENOSENSE project is to develop a transformative method to taking toxicity testing towards not only animal-free, but also cell-free, testing methods, building on the ethical imperative of the 3R principles, by building on the convergence of environmental toxicology, computational biology, biotechnology and nanotechnology, and using collaborative research and co-design with relevant industrial partners directly integrated in the project to develop a versatile Lab-on-a-Chip-based xenosensing biosensor.