Quick and robust method for the generation of human iPSC-derived choroid plexus organoids.

The choroid plexus (ChP) is a key brain structure responsible for cerebrospinal fluid (CSF) production and forms a selective barrier that regulates brain homeostasis and immune surveillance. In vitro models of ChP are essential for studying CSF dynamics, viral entry, neuroinflammation, and CNS drug transport; yet current organoid protocols remain complex, slow, and difficult to reproduce. Here, we report a quick and robust method for the generation of human iPSC-derived ChP organoids that is xeno-free and serum-free, scalable, and reproducible. Early GSK3β inhibition and transient WNT modulation guide organoids toward cystic ChP-enriched structures, confirmed by ventricle-like morphology, and expression of canonical markers (TTR, ZO-1). This minimal workflow enables rapid production of ChP-like organoids that recapitulate ChP morphology and marker expression, providing a potential platform for studies of cerebrospinal fluid physiology, barrier modelling, and translational neuroscience.