Capillary electrophoresis of induced pluripotent stem cells during differentiation toward neurons

• Multiplied iPS cells express SSEA-1, Oct4, SOX2, and Nanog, assuring phenotypic pluripotency.
• A longer induction with NGF produces a higher quantity of neuron-like cells.
• A high NGF concentration yields short migration time and accelerates neuronal differentiation.
• Neuron-like cells show a high electrophoretic mobility and fixed charge density.

Understanding of electrical properties of neurons, derived from induced pluripotent stem cells (iPSCs), is an emerging issue in treating human neurological disorders. This study presents the variation in zeta potential and electrophoretic mobility of iPSCs during differentiation toward neurons. The fixed charge density of differentiating iPSCs was also evaluated using Ohshima's soft particle theory. The optical images demonstrated that in passage 12, a cluster of iPSCs emerged at day 5. The colonial expansion enlarged the cluster size and an increasing culture period led to a mature multiplication. In addition, immunochemical staining with stage-specific embryonic surface antigen-1, Oct4, Sox2, and Nanog assured the starting iPSCs of phenotypic pluripotency. A longer period of induction with nerve growth factor (NGF) produced a higher quantity of neuron-like cells. Moreover, a high concentration of NGF yielded short migration time of differentiating iPSCs, suggesting a raised surface charge and accelerated neuronal differentiation. An increasing NGF concentration and inductive span enhanced the absolute value of zeta potential, electrophoretic mobility, and fixed charge density of differentiating iPSCs. The propagated colony of embryonic phenotype and membrane charge of differentiating iPSCs can be identified and controlled as a biophysical foundation for future clinical application.