Organoids, organ-on-a-chip, separation science and mass spectrometry: An update

Organoids are 3D models of organs, grown in the laboratory from stem cells. An organ model grown/ placed in microfluidic devices is commonly termed an "organ-on-a-chip". Organoids and organ-on-a-chip devices are becoming important tools for studying physiology, disease modeling, drug discovery, personalized medicine, toxicology, and organ development/embryogenesis. We review how mass spectrometry is used for studying organoids and organ-on-a-chip-derived material. We first focus on proteomics, metabolomics/lipidomics, and hormones, typically discussing liquid chromatography-mass spectrometry (LC-MS) approaches. We then review work on mass spec-trometry imaging (MSI) of organoids and discuss organ-on-a-chip coupled with mass spectrometry. The review focuses on research developments from the past four years. Mass spectrometric analysis of organoids and organ-on-a-chip has allowed novel insights on devel-opment and disease of e.g. brain, liver, and tumors, demonstrating potential for replacing or com-plementing animal models and other traditional model systems. Additional applications are emerging, e.g. related to sports doping and environmental toxicology. (c) 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).