Eur. Phys. J. E (2019) 42: 33
https://doi.org/10.1140/epje/i2019-11793-y

Regular Article

Transport of dynamic biochemical signals in a microfluidic single cell trapping channel with varying cross-sections

¹ Department of Biomedical Engineering, Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, No. 2, Linggong Rd., 116024, Dalian, China
² School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, No. 2, Linggong Rd., 116024, Dalian, China
³ Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, 63130-4899, St. Louis, MO, USA

^* e-mail: krqin@dlut.edu.cn

Received: 30 March 2018
Accepted: 8 February 2019
Published online: 21 March 2019

Abstract

Dynamic biochemical signal control in vitro is important in the study of cellular responses to dynamic biochemical stimuli in microenvironment in vivo. To this end, we designed a microfluidic single cell trapping channel with varying cross-sections. In this work, we analyzed the transport of dynamic biochemical signals in steady and non-reversing pulsatile flows in such a microchannel. By numerically solving the 2D time-dependent Taylor-Aris dispersion equation, we studied the transport mechanism of different signals with varying parameters. The amplitude spectrum in steady flow shows that the trapping microchannel acts as a low-pass filter due to the longitudinal dispersion. The input signal can be modulated nonlinearly by the pulsatile flow. In addition, the nonlinear modulation effects are affected by the pulsatile flow frequency, the pulsatile flow amplitude and the average flow rate. When the flow frequency is much smaller or larger than that of the biochemical signal, the signal can be transmitted more efficiently. Besides, smaller pulsatile flow amplitude and larger average flow rate can decrease the nonlinear modulation and promote the signal transmission. These results demonstrate that in order to accurately load a desired dynamic biochemical signal to the trapped cell to probe the cellular dynamic response to the dynamic biochemical stimulus, the transport mechanism of the signals in the microchannel should be carefully considered.