The volatilome of human embryonic stem cells using selected Ion Flow Tube Mass Spectrometry
Barreto S (1)*, Forsyth NR (1), Rutter AV (1)
(1) Institute for Science and Technology in Medicine, School of Pharmacy and Bioengineering, Keele University, England, UK
Human embryonic stem cells (hESCs) can multiply indefinitely and generate cells from the three germ layers. These unique abilities have multiple therapeutic applications. Unfortunately, the use of hESCs is associated with a risk of tumorigenicity, and most studies now focus on utilising their differentiated progeny. Therefore, it is imperative that any residual hESCs are eliminated before translating the cell therapy into clinical practice. Measuring hESCs metabolism could represent a potential detection method. Here, we used selected ion flow tube-mass spectrometry (SIFT-MS) to detect volatile organic compounds (VOCs) in the headspace of hESCs, non-invasively, across two oxygen conditions (21% and 2%). The headspace of hESC conditioned media (CM) cultured in either oxygen condition was analysed using SIFT-MS. Furthermore, the effects of freeze/thaw of CM on the VOC emission were assessed as freezing of samples provides a fast, time-effective, and convenient method to analyse samples at a later date. Preliminary results show that it is possible to detect VOCs in the headspace of hESC CM at trace levels, parts-per-billion (ppb), in both frozen and fresh media. Additionally, different VOC concentrations were detected in frozen and fresh media cultured at either 21% or 2% oxygen. The concentration of most VOCs was overall higher in 2% oxygen for both fresh and frozen media. Additionally, VOCs, like acetone and dimethyl-sulphide/ethanethiol, decreased, whereas others (acetic acid and dimethyl-sulphoxide) increased when freezing media. Temperatures and oxygen conditions might lead to an altered VOC profile, altering hESC metabolism and consequently influencing the VOC profile.