Xin Hua oral presentation (SN3-Wed2-2-1)
Investigation of nanoparticle-induced lipids changes on single cell surface by ToF-SIMS
East China University of Science and Technology, 130 Meilong Road, 200237 Shanghai, China
Lipids are the main component of cell membrane. They not only provide structural support of cells, but also directly participate in complex cellular metabolic processes . Lipid signaling is a vital part of cell signalling. Evidence showed that abnormal cellular metabolism may induce changes of lipids composition. Besides, owing to single cell heterogeneity, it is necessary to distinguish different behaviors of individual cells. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a sensitive surface analysis technique with high mass resolution and spatial resolution, which is promising in single cell surface analysis.
Herein, we use ToF-SIMS to investigate nanoparticle induced lipids changes on single cell surface. Delayed extraction mode of ToF-SIMS was used to maintain simultaneously high mass resolution of mass spectra and high spatial resolution of chemical mapping. 10 nm Ag NPs were chosen to induce lipids changes in macrophage cells. Principal components analysis (PCA) clearly showed changes of certain lipids on cell membrane after treated with Ag NPs. PCA score plots showed a good separation among cells treated with low dose and high dose of Ag NPs, which was in good agreement with MTT assay result (Figure 1). The loadings plots revealed that the separation was mainly due to changes of cholesterol, diacylglycerol as well as some monoacylglycerol species. Meanwhile, the chemical mapping of single cell components showed that cholesterol and diacylglycerol tend to migrate to the surrounding of cells after Ag NPs treatment. Our results demonstrated the feasibility of ToF-SIMS for characterizing the changes of the lipids on single cell surface, resulting in a better understanding of the pathway for cell-nanoparticle interactions.