Advances in three-dimensional fish cell models for aquatic toxicology

Aquatic ecosystems are increasingly threatened by diverse environmental pollutants, such as pharmaceuticals, personal care products, and persistent organic contaminants. While traditional in vivo fish models and two-dimensional (2D) cell cultures provide valuable mechanistic insights, they are limited by ethical concerns and insufficient ecological relevance. In contrast, three-dimensional (3D) fish cell culture systems, including spheroids, organoids, and organ-on-a-chip platforms, have been established as powerful tools in toxicology. These advanced models more accurately replicate native tissue architecture, maintain metabolic functions over extended periods, and facilitate long-term exposure studies, thereby enabling a comprehensive assessment of pollutant toxicity, bioaccumulation potential, and toxic mechanisms. The efficacy of 3D systems has been demonstrated in recent applications for evaluating endocrine-disrupting effects, pharmaceutical metabolism, host-pathogen interactions, and the chronic effects of organic pollutants. Notably, these models exhibit superior predictive capacity compared to conventional 2D assays. Despite significant advancements, challenges remain in standardizing protocols across fish species, improving analytical compatibility, and ensuring long-term culture stability. Advancing these innovative models through interdisciplinary collaboration will promote their integration into ecotoxicological testing and ecological risk assessment. Such progress is essential to support global initiatives aimed at advancing animal-free toxicology.