Organoid-in-a-column coupled on-line with liquid chromatography-mass spectrometry

Organoids are stem-cell derived mini organs and are emerging tools for e.g. developmental biology and drug development. We have packed empty liquid chromatography column housings (micro format) with induced pluripotent stem cell (iPSC) derived hepatic organoids, and coupled these organoid-in-a-column units directly to liquid chromatography-mass spectrometry. The system has been charged with heroin, followed by on-line monitoring of the drugs phase 1 metabolism. Using a C4 stationary phase for reverse phase liquid chromatography, small molecule measurements were not significantly affected by liver organoid medium matrix (consisting of e.g. fetal bovine serum). Enzymatic metabolism of heroin was reliably detected using a triple quadrupole instrument over a period of two days, demonstrating increased metabolite production over time and serving as a proof-of-concept for on-line coupling of organoids and mass spectrometry.