Organoids and mini-organs: Introduction, history, and potential

Abstract Organoids are three-dimensional assemblies that contain multiple cell types, arranged similarly to the cells in a specific tissue, at least at the micro-scale; mini-organs add to this micro-realism a realistic macro-scale anatomy as well. Researchers have been producing organoids for at least 60 years, initially to explore basic mechanisms of development, but more recently as tools for medical research. Organoids made from human cells are particularly valuable for preclinical studies, because they avoid the need to extrapolate results from one species to another. This chapter outlines the history of organoid research, describes briefly how typical organoids are produced, and goes on to describe their use in pharmacology, toxicology, oncology, and microbiology. It includes an indication of how organoids can be turned into mini-organs, and ends with some cautionary notes on the limitations of current techniques.