Hybrid modeling of electroporation and impedance spectroscopy for label free characterization of stem cells
Sameh Sherif, Yehya H. Ghallab, Yehea Ismail
Label-free, non-destructive characterization of stem-cell differentiation states remains an important goal in regenerative medicine and cell therapy. Existing computational frameworks commonly treat electroporation either at the tissue scale or for simplified single-cell geometries, and relatively few studies connect time-domain electroporation observables with swept-frequency impedance features measured in a microfluidic platform. This study presents a revised hybrid analytical-numerical and experimental framework for comparing undifferentiated human mesenchymal stem cells (hMSCs) with osteogenic-committed hMSCs. The numerical models are parameterized using the cell-type values : an undifferentiated hMSC model with representative radius [Formula: see text], cytoplasmic conductivity [Formula: see text], membrane capacitance [Formula: see text], and characteristic electroporation voltage [Formula: see text]; and an osteogenic hMSC model with [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text]. Both models are placed in the same microfluidic electrode environment and excited by electric-field pulses ([Formula: see text] to [Formula: see text], rise time 1 ns). The passive Schwan RC time constants are [Formula: see text] for undifferentiated hMSCs and [Formula: see text] for osteogenic hMSCs; the plotted post-threshold rise times are shorter, on the order of [Formula: see text] to [Formula: see text]. The passive polar transmembrane potentials at [Formula: see text] are approximately [Formula: see text] and 9.75 V, respectively. Swept-frequency impedance spectroscopy ([Formula: see text] to [Formula: see text]) performed on undifferentiated and osteogenic-committed hMSCs provides the matched frequency-domain comparison: low-frequency impedance, series resistance, reactance trough depth, phase angle, and voltage-dependent impedance drop are extracted at applied voltages of 1, 5, 10, 15, 20, and 25 V. The experimental data show that osteogenic hMSCs have higher baseline impedance ([Formula: see text] vs. [Formula: see text] at [Formula: see text], [Formula: see text]), whereas undifferentiated hMSCs exhibit the stronger high-voltage impedance drop at [Formula: see text] approximately (92.4 % compared with 86.9 % for osteogenic hMSCs). Calibrated 10.4 [Formula: see text]m and 24.9 [Formula: see text]m polystyrene microbeads are included as cell-free size standards for the impedance workflow. The combined results define a cell-type feature space [Formula: see text] for future label-free classification studies. The present work should be interpreted as a matched modelling and impedance-analysis framework; definitive biological classification, direct pore imaging, viability validation, and trained classifier performance remain outside the scope of this study.