We report the development of a 3D OrbiSIMS instrument for label-free biomedical imaging. It combines the high spatial resolution of secondary ion mass spectrometry (SIMS; under 200 nm for inorganic species and under 2 μm for biomolecules) with the high mass-resolving power of an Orbitrap (>240,000 at m/z 200). This allows exogenous and endogenous metabolites to be visualized in 3D with subcellular resolution. We imaged the distribution of neurotransmitters—gamma-aminobutyric acid, dopamine and serotonin—with high spectroscopic confidence in the mouse hippocampus. We also putatively annotated and mapped the subcellular localization of 29 sulfoglycosphingolipids and 45 glycerophospholipids, and we confirmed lipid identities with tandem mass spectrometry. We demonstrated single-cell metabolomic profiling using rat alveolar macrophage cells incubated with different concentrations of the drug amiodarone, and we observed that the upregulation of phospholipid species and cholesterol is correlated with the accumulation of amiodarone.

中文翻译：

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3D OrbiSIMS —具有亚细胞横向分辨率和高质量分辨能力的无标记代谢成像

我们报告了用于无标签生物医学成像的3D OrbiSIMS仪器的开发。它结合了二次离子质谱的高空间分辨率（SIMS；对于无机物质而言小于200 nm，对于生物分子而言小于2μm）与Orbitrap的高质量分辨能力（m / z > 240,000）200）。这使外源和内源性代谢物能够以亚细胞分辨率在3D模式下可视化。我们对小鼠海马中的高光谱置信度成像了神经递质-γ-氨基丁酸，多巴胺和5-羟色胺的分布。我们还假定地注释和映射了29个磺基糖鞘脂和45个甘油磷脂的亚细胞定位，并且我们通过串联质谱法确认了脂质身份。我们展示了使用大鼠肺泡巨噬细胞与不同浓度的药物胺碘酮温育的单细胞代谢组学分析，并且我们观察到磷脂种类和胆固醇的上调与胺碘酮的积累有关。