Dear Colleagues,

In vitro bioassays play a key role in assessing the hazard and risk of substances and complex environmental or anthropic mixtures, allowing for faster screening of substances than when using tests conducted in vivo. Thanks to the strong technological development, many advances have been made in recent years in the field of biological assays applied to risk assessment, with the generation of increasingly complex models close to the tissues and organs to be studied and allowing the discovery of more precocious, precise, and specific responses. In parallel, the recognition of in vitro methods as reliable and effective screening tools has promoted the establishment of high-throughput screening programs for prioritization of chemicals based on in vitro bioactivity profiling, such as the ToxCast program, which prioritizes toxicity testing of environmental chemicals. The huge amount of data generated by these programs has then allowed the integration of in vitro models with computational and machine learning techniques to generate integrated approaches to testing and assessment to address the limited testing efforts toward chemicals potentially representing the greatest hazard to human health and the environment.

This Special Issue seeks to highlight timely research studies addressing the use of in vitro models as supporting tools for the hazard and risk assessment of stressors, including chemicals, physical agents, and chemical mixtures derived from environmental or anthropic sources, paying particular attention to emerging sanitary and environmental challenges. Studies using co-culture, 3D models, organoids, and induced pluripotent stem cells as well as ecotoxicological assays with in vitro model organisms (e.g., bacteria, algae, embryos, fish cell lines) are also of interest.

For this Special Issue, authors are welcome to submit original research papers and reviews.

Specific areas of research may include, but are not limited to, the following:

1. Discovery and validation of new in vitro models and endpoints to investigate the effects of toxicants on humans and ecological receptors;
2. In vitro epigenetic effects of chemicals;
3. Multi-omics strategies to discover new potential biomarkers of effects of emerging contaminants, including nanomaterials, microplastics, and drugs;
4. Multi-omics strategies to define or support the adverse outcome pathways of traditional and new toxicants;
5. Quantitative risk assessment using in vitro data;
6. New approaches for in vitro to in vivo extrapolation for quantitative risk assessment;
7. Integrated approaches to testing and assessment (IATA) involving in vitro data;
8. Species-specific in vitro models for target organ toxicity studies of veterinary interest.

We look forward to receiving your contributions.

Dr. Diego Baderna
Dr. Nathalie Steimberg”