Impact of the human mesenchymal stem cells donor on conditional medium composition

Exosomes produced by Mesenchymal Stem Cells (MSCs) can represent a very appealing strategy for cell-free therapies. However, to achieve this reality it is necessary to further understand the process associated to the MSC culture when conditioned to produce exosomes. In the present work, it was evaluated how different MSC obtained from different donors may affect the conditioned media composition and how this can be influenced by the conditioned media type (DMEM versus Xeno-Free medium, XF). The molecular fingerprint of the conditioned media composition was obtained by mid-infrared (MIR) spectroscopy, as this technique reflects fundamental vibrations of a high diversity of functional chemical groups present in biological samples. It was observed by principal component analysis of the second derivative spectra of conditioned media that the media chemical composition depends more from the MSCs donor than the conditioning days. Diverse spectral regions, characteristic of defined chemical groups, enabled to discriminate the chemical composition of the media according to the MSC donor. All of this was observed in both types of media (DMEM and XF). This work is a step forward to understand how different MSC donors and conditioned media may affect the exosomes characteristics.