Discussion

Mass spectrometry imaging (MSI) is increasingly being used to assess the spatial distribution of drugs, their metabolites and biomarkers of their biological effects. While historically an ex vivo technique, its use with a range of tissue culture systems is currently being explored.

Much of the understanding and translation of drug effects are underpinned by key assumptions about “free drug” concentrations in tissues relative to those in plasma. Understanding where such assumptions are less robust is important for targeting the use of MSI, as it, like all analytical techniques, assesses total drug concentrations. Although, advances in instrumentation are driving the technology towards sub-cellular spatial resolution, and understanding of intracellular drug kinetics, the “free-drug” question remains.

This presentation will outline the utility of a range of MSI techniques, highlighting that current technologies offer key insights into drug disposition within ex vivo tissues and in vitro test systems, a key translational step between simple cell based assays and in vivo effect.