LC-MS/MS lipidomics data: Enhancing the Accuracy of Surgical Debridement Following Burns Trauma via Application of Rapid Evaporative Ionisation-Mass Spectrometry (REIMS)
LC-MS/MS lipidomics data from the manuscript titled: Enhancing the Accuracy of Surgical Debridement Following Burns Trauma via Application of Rapid Evaporative Ionisation-Mass Spectrometry (REIMS) Publication Abstract: Background Surgical debridement is a necessary procedure for burn patients that require the removal of eschar. The extent of debridement is currently guided by clinical judgement, with excess debridement of healthy tissue potentially leading to excessive scar, or inadequate debridement increasing risk of infection. Thus, an objective real-time measure to facilitate accurate debridement could support clinical judgement and improve this surgical procedure. This study was designed to investigate the potential use of Rapid evaporative ionisation mass spectrometry (REIMS) as a tool to support data-driven objective tissue debridement. Methods Data were acquired using a multi-platform approach that consisted of both Rapid Evaporative Ionisation Mass Spectrometry (REIMS) performed on intact skin, and comprehensive liquid chromatography-mass spectrometry (LC-MS/MS) lipidomics performed on homogenised skin tissue extracts. Data were analysed using principal components analysis (PCA) and multivariate orthogonal projections to latent squares discriminant analysis (OPLS-DA) and logistic regression to determine the predictability of the models. Results PCA and OPLS-DA models of the REIMS and LC-MS/MS lipidomics data reported separation of debrided and healthy tissue. Molecular fingerprints generated from REIMS analysis of healthy skin tissue revealed a high degree of heterogeneity, however, intra-individual variance was smaller than inter-individual variance. Both platforms indicated high levels of skin classification accuracy. In addition, OPLS-DA of the LC-MS/MS lipidomic data revealed significant differences in specific lipid classes between healthy control and debrided skin samples; including lower free fatty acids (FFA), monoacylglycerols (MAG), lysophosphatidylglycerol (LPG) and lysophosphatidylethanolamines (LPE) in debrided tissue and higher lactosylceramides (LCER) and cholesterol esters (CE) compared to healthy control tissue. Conclusions Having established the heterogeneity in the biochemical composition of healthy skin using REIMS and LC-MS/MS, our data show that REIMS has the potential to distinguish between debrided and healthy skin tissue samples. This pilot study suggests that REIMS may be an effective tool to support accurate tissue debridement during burn surgery.
Steps to reproduce
A volume of 1800 μL of IPA was added to 10 g of skin sample in a 2 mL microcentrifuge tube prior to vortex mixing. The solvent was extracted and placed into a new 2 mL microcentrifuge tube and centrifuged at 13,000 g for 2 minutes. The supernatant was subsequently transferred to a vial and used for the LC-MS analysis, while the protein pellet was discarded. LC-MS/MS data were generated using a targeted lipidomic method that quantified lipids from 20 lipid sub-classes; triacylglycerides (TAGs), diacylglycerides (DAGs), monoacylglycerols (MAGs), free fatty acids (FFAs), sphingomyelins (SMs), ceramides (CERs), dihydroceramides (DCERs), hexosylceramides (HCERs), lactosylceramides (LCERs), cholesterol esters (CEs), phosphocholines (PCs), phosphoethanolamines (PEs), phosphoglycerols (PGs), phosphoinositols (PIs), phosphoserines (PSs), lysophosphocholines (LPCs), lysophosphoethanolamines (LPEs), lysophosphoglycerols (LPGs), lysophosphoinositols (LPIs) and lysophosphoserines (LPSs). The analytical system comprised an ExionLCTM coupled to a QTRAP 6500+ system (Sciex, MA, USA). Reversed-phase separation was performed using an Acquity BEH C18 1.7 μm, 2.1 x 100 mm column (Waters Corp., MA, USA) at 60 °C. Mobile phase A consisted of water/acetonitrile/propan-2-ol (50/30/20, v/v/v) containing 10 mM ammonium acetate and mobile phase B consisted of propan-2-ol/acetonitrile/water (90/9/1, v/v/v) containing 10 mM ammonium acetate. The flow rate was 0.4 mL/min with gradient elution starting at 10 % B, increasing to 45 % B at 2.7 min, 53 % at 2.8 min, 60% B at 8.0 min, 80 % B at 8.1 min and holding at 80 % B until 11.5 min, 100 % B at 12.0 min for 1 min before returning to 10 % B for a 2 min re-equilibration for a total cycle time of 15 min. The injection volume was 5 μL. The Sciex QTRAP 6500+ was operated with electrospray ionisation using polarity switching and predefined MRM transitions (Sciex sMRM Pro builder) set to in-house chromatographic retention time windows. The following mass spectrometer settings were used; capillary voltage, 5500 V (positive ion mode) and -4500 V (negative ion mode); temperature, 300 °C; curtain gas, 20 psi; ion source gas 1, 40 psi; ion source gas 2, 60 psi. Data were acquired using Analyst®1.7.1.