Rapid and Live-cell Detection of Senescence in Mesenchymal Stem Cells by Micro Magnetic Resonance Relaxometry

Detection of cellular senescence is important quality analytics for cell therapy products, including mesenchymal stromal cells (MSCs). However, their detection is critically limited by the lack of specific markers and the destructive assays used to read out these markers. Here, we establish a rapid, live-cell assay for detecting senescent cells using heterogeneous mesenchymal stromal cell (MSC) cultures. We report that the T2 relaxation time measured by microscale Magnetic Resonance Relaxometry ({micro}MRR), which is related to intracellular iron accumulation, correlates strongly with senescent markers in MSC cultures under diverse conditions including different passages and donors, size-sorted MSCs by inertial spiral microfluidic device, and drug-induced senescence. In addition, the live-cell and non-destructive method presented here has general applicability to other cells and tissues, and can critically advance our understanding of cellular senescence.