Electromembrane Extraction Provides Unprecedented Selectivity for Drugs in Cell Culture Media Used in Organoid and Organ-on-Chip Systems.

The use of organoids and organ-on-chip technologies as nonanimal methodologies in drug discovery and personalized medicine is rapidly expanding. However, the complexity and small volumes of organoid culture samples present significant analytical challenges, e.g., in drug analysis using liquid chromatography-mass spectrometry (LC-MS). Essentially an electrophoresis across an oil membrane, electromembrane extraction (EME) offers a promising approach for measuring drugs, as it is, for example, compatible with small samples such as organoid and organ-on-chip formats. Given the potential of the technology, there is a need to assess the extraction purity of EME extracts to ensure EME's compatibility with high-throughput, downstream analysis. This study evaluates the effectiveness of EME for sample cleanup in various common cell culture media used for organoids and organs-on-chips. The media were spiked with 90 small-molecule drugs. Using gel electrophoresis (sodium dodecyl sulfate polyacrylamide gel electrophoresis), high-resolution nuclear magnetic resonance spectroscopy, and LC-MS, we demonstrate that EME provides exhaustive removal of unwanted medium components (proteins, polar molecules, and apolar/neutral molecules) while selectively extracting the spiked small-molecule drugs. The approach was demonstrated with human stem-cell-derived liver organoids, allowing simple detection and monitoring of telltale cytochrome P450 metabolism. Taken together, our observations highlight an unprecedented ability of EME to provide sample cleanup for drug analysis in matrixes compatible with organoids and organ-on-chip technology.