Investigation of Silver Nanoparticle Induced Lipids
Changes on a Single Cell Surface by Time-of-Flight Secondary Ion Mass
Spectrometry
- Publication date
- Publisher
Abstract
Lipids are the main
component of the cell membrane. They not only
provide structural support of cells but also directly participate
in complex cellular metabolic processes. Lipid signaling is an important
part of cell signaling. Evidence showed that abnormal cellular metabolism
may induce lipids changes. 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 spatial resolution, which is
useful in single cell surface analysis. Herein, we used ToF-SIMS to
investigate silver nanoparticle induced lipids changes on the surface
of single macrophage cells. Delayed extraction mode of ToF-SIMS was
used to simultaneously obtain high mass resolution of mass spectra
and high spatial resolution of single cell chemical imaging. Principle
component analysis (PCA) results showed good agreement with the cytotoxicity
assay results. Clear distinctions were observed between the cell groups
treated with high or low dose of silver nanoparticles. The loadings
plots revealed that the separation was mainly due to changes of cholesterol
and diacylglycerol (DAG) as well as monoacylglycerol (MAG). Meanwhile,
the chemical mapping of single cell components showed that cholesterol
and DAG tend to migrate to the surrounding of the cells after high
dose silver nanoparticles (Ag NPs) treatment. Our results demonstrated
the feasibility of ToF-SIMS for characterizing the changes of the
lipids on a single cell surface, providing a better understanding
of the mechanism of cell–nanoparticle interactions at the molecular
level