Characterization of lipid components in human cells by means of ATR FT-IR spectroscopy

The study of lipid components in human cells is of fundamental importance in many cellular functions, such as cell adhesion and migration, formation of membrane domain, DNA damage response, senescence, ageing autophagy, and apoptosis. For this reason, we investigated the different phospholipids and sphingolipids components of human cells by using Fourier Transform Infrared (FT-IR) spectroscopy that allows lipids detection and their characterization in biological samples. Commercial samples of phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylinositol (PI), phosphatidylserine (PS), ceramide (Cer), ceramide 1 -phosphate (C1P), sphingosine 1 phosphate (SIP) and sphingomyelin (SM) were used for collecting spectra using ATR acquisition mode. The infrared spectra of different lipids show the contribution of various functional groups from hydrocarbon chains and polar head groups. The present analysis of these spectra contributed to a better understanding of the characteristics of infrared spectra of single lipid components that can be considered a preliminary step in the FT-IR characterization of lipids extracts from human cells affected by pathologies or exposed to different external agents.