Mass Spectrometry Imaging of Triglycerides in Biological Tissues by Laser Desorption Ionization from Silicon Nanopost Arrays

AbstractMass spectrometry imaging (MSI) is used increasingly to simultaneously detect a broad range of biomolecules, while mapping their spatial distributions within biological tissue sections. Matrix ‐assisted laser desorption ionization (MALDI) is recognized as the method‐of‐choice for MSI applications due in part to its broad molecular coverage. In spite of the remarkable advantages offered by MALDI, imaging of neutral lipids, such as triglycerides (TGs), from tissue has remained a signi ficant challenge due to ion suppression of TGs by phospholipids, e.g., phosphatidylcholines (PCs). To help overcome this limitation, silicon nanopost array (NAPA) substrates were introduced to selectively ionize TGs from biological tissue sections. This matrix‐free laser desorption ionization (LDI ) platform was previously shown to provide enhanced ionization of certain lipid classes, such as hexosylceramides (HexCers) and phosphatidylethanolamines (PEs) from mouse brain tissue. In this work, we present NAPA as an MSI platform offering enhanced ionization efficiency for TGs from biological ti ssues relative to MALDI, allowing it to serve as a complement to MALDI‐MSI. Analysis of a standard lipid mixture containing PC(18:1/18:1) and TG(16:0/16:0/16:0) by LDI from NAPA provided an ~49 and ~227‐fold higher signal for TG(16:0/16:0/16:0) relative to MALDI, when analyzed without and with t he addition of a sodium acetate, respectively. In contrast, MALDI provided an ~757 and ~295‐f...
Source: Journal of Mass Spectrometry - Category: Chemistry Authors: Tags: SPECIAL ISSUE ‐ RESEARCH ARTICLE Source Type: research