Luxembourg Institute of Science and Technology (LIST), Molecular and Thermal Analysis, Materials Research and Technology, L-4422 Belvaux, Luxembourg.
Pierre Fabre Dermo-Cosmétique et Personal Care, Centre R&D Pierre Fabre, Avenue Hubert Curien, 31025 Toulouse Cedex 01, France.
J Am Soc Mass Spectrom. 2023 Nov 1;34(11):2469-2480. doi: 10.1021/jasms.3c00185. Epub 2023 Oct 16.
Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) has become an important tool for skin analysis, as it allows the simultaneous detection and localization of diverse molecular species within a sample. The use of and human skin models is costly and presents ethical issues; therefore, reconstructed human epidermis (RHE) models, which mimic the upper part of native human skin, represent a suitable alternative to investigate adverse effects of chemicals applied to the skin. However, there are few publications investigating the feasibility of using MALDI MSI on RHE models. Therefore, the aim of this study was to investigate the effect of sample preparation techniques, i.e., substrate, sample thickness, washing, and matrix recrystallization, on the quality of MALDI MSI for lipids analysis of the SkinEthic RHE model. Images were generated using an atmospheric pressure MALDI source coupled to a high-resolution mass spectrometer with a pixel size of 5 μm. Masses detected in a defined region of interest were analyzed and annotated using the LipostarMSI platform. The results indicated that the combination of (1) coated metallic substrates, such as APTES-coated stainless-steel plates, (2) tissue sections of 6 μm thickness, and (3) aqueous washing before HCCA matrix spraying (without recrystallization), resulted in images with a significant signal intensity as well as numerous / values. This refined methodology using AP-MALDI coupled to a high-resolution mass spectrometer should improve the current sample preparation workflow to evaluate changes in skin composition after application of dermatocosmetics.
基质辅助激光解吸/电离（MALDI）质谱成像（MSI）已成为皮肤分析的重要工具，因为它允许在样品中同时检测和定位多种分子种类。使用 和 人体皮肤模型成本高且存在伦理问题；因此，重建的人表皮（RHE）模型，模拟天然人皮肤的上部，是研究化学物质对皮肤应用的不良影响的合适替代品。然而，很少有出版物研究在 RHE 模型上使用 MALDI MSI 的可行性。因此，本研究的目的是研究样品制备技术，即基底、样品厚度、洗涤和基质重结晶，对 SkinEthic RHE 模型的脂质分析的 MALDI MSI 质量的影响。使用大气压 MALDI 源与具有 5 μm 像素大小的高分辨率质谱仪生成图像。使用 LipostarMSI 平台分析和注释在感兴趣区域中检测到的质量。结果表明，（1）涂有 APTES 的金属基底（如 APTES 涂覆的不锈钢板），（2）厚度为 6 μm 的组织切片，以及（3）HCCA 基质喷雾前的水性洗涤（不进行重结晶）的组合，导致图像具有显著的信号强度和大量的 / 值。这种使用 AP-MALDI 结合高分辨率质谱仪的改进方法学，应该改进当前的样品制备工作流程，以评估在应用皮肤化妆品后皮肤成分的变化。
