Functional reorganization of excitable cell culture system for screening novel fluorescent probes

Abstract

The second near-infrared window ranged between 1 and 1.5 micron, NIR-II, has advantages for deep tissue imaging with extrinsic fluorophores due to lacking autofluorescence, low light absorption, and reduced scattering. Most of the proposed probes were used for labeling with antibodies. As a new application, we plan to monitor electrical activity in a living tissue noninvasively using membrane potential dye with NIR-II fluorescence. So we need the excitable cell culture system to screen a candidate of such dyes. In contrast to neuron and skeletal muscle cell, cardiomyocytes showed a relative slow response with depolarization during several thousand milliseconds. Using cardimyocytes primary culture and iPS cardiomyocytes, quantum dots were evaluated. Furthermore C2C12 skeletal myoblasts were morphologically differentiated to myotubes under the optimal conditions, and the electrical stimulation-induced contraction of the myotubes was monitored optically. This myotube system would permit screening for potential dye in NIR-II.