organoidides

Organoidides refer to a class of three-dimensional, organ-like cellular assemblies that are derived from stem cells and cultured to resemble specific organs or tissues. The term is used in a minority of the literature to describe organoid-derived constructs that are intermediate between traditional organoids and larger tissue-engineered tissues.

Taxonomy and naming: The term "organoidide" is not part of formal taxonomic nomenclature. It is not consistently defined, and different groups have used it to describe slightly different entities, from compact, spherical organoid aggregates to elongated tubular structures with partial tissue organization.

Characteristics and generation: Organoidides commonly arise from pluripotent or lineage-committed stem cells embedded in extracellular matrices or synthetic hydrogels. They show multiple differentiated cell types, lumen formation, and organizing cues that mimic aspects of organ architecture. Their development often relies on signaling pathways such as WNT, Notch, and FGF, and can be guided by mechanical cues.

Applications: In research, organoidides are used for disease modeling, drug screening, and studies of tissue development. They offer a scale and composition closer to mature tissues than single-cell cultures, while remaining more controllable and reproducible than immature organoids.

Limitations and outlook: The term remains informal, and organoidides do not fully recapitulate organ complexity. Variability, maturation, and integration with vasculature are ongoing challenges. Further standardization and reporting are needed for cross-study comparisons.