Online LC-MS/MS Analysis for Profiling Peptide Hormone Secretion Dynamics from Islets of Langerhans

Analytical Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 11, 2025

Multiple peptide hormones are secreted from islets of Langerhans to maintain blood glucose homeostasis. Defects in the amount and patterns hormone secretion can lead metabolic disorders, such as diabetes. To understand relationships between peptides, analytical methods that quantify multiple short time increments required. this end, an automated online system was developed for sampling perfusate ∼30 human held on a glass microfluidic device with sequential liquid chromatography (LC)-MS/MS runs every 2 min resolve dynamics. Islet mixed isotopically labeled internal standard loaded into μL sample loop which injected 0.1 1.9 onto 2.1 mm × 30 (I.D. length) C18 column at 70 °C. Online detection insulin, C-peptide, glucagon, somatostatin levels performed using triple quadrupole mass spectrometer. Optimization separation conditions linear solvent strength theory enabled rapid four peptides. Calibration curves were 0.5 50 nM RSD all analytes 3-15% <3% retention times. Results showed dynamics first-phase insulin release negatively correlated glucagon insulin. This simple LC-MS method used single 6-port valve is expected be useful examining other biologically relevant molecules could applied biological systems investigate cellular communication.

Language: Английский

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

Analytical Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 24, 2025

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

Language: Английский

Construction of a two-dimensional magnetic solid phase extraction microfluidic chip/tandem mass spectrometry platform for the determination of cytarabine in plasma

Microchemical Journal, Journal Year: 2024, Volume and Issue: 207, P. 112150 - 112150

Published: Nov. 10, 2024

Language: Английский