A microfluidic device with spatiotemporal wall shear stress and ATP signals to investigate the intracellular calcium dynamics in vascular endothelial cells

Abstract

Intracellular calcium dynamics plays an important role in the regulation of vascular endothelial cellular functions. In order to probe the intracellular calcium dynamic response under synergistic effect of wall shear stress (WSS) and adenosine triphosphate (ATP) signals, a novel microfluidic device, which provides the adherent vascular endothelial cells (VECs) on the bottom of microchannel with WSS signal alone, ATP signal alone, and different combinations of WSS and ATP signals, is proposed based upon the principles of fluid mechanics and mass transfer. The spatiotemporal profiles of extracellular ATP signals from numerical simulation and experiment studies validate the implementation of our design. The intracellular calcium dynamics of VECs in response to either WSS signal or ATP signal alone, and different combinations of WSS and ATP signals have been investigated. It is found that the synergistic effect of the WSS and ATP signals plays a more significant role in the signal transduction of VECs rather than that from either WSS signal or ATP signal alone. In particular, under the combined stimuli of WSS and ATP signals with different amplitudes and frequencies, the amplitudes and frequencies of the intracellular Ca dynamic signals are observed to be closely related to the amplitudes and frequencies of WSS or ATP signals.

A microfluidic array device for single cell capture and intracellular Ca2+ response analysis induced by dynamic biochemical stimulus

“…It is noteworthy that the microchannels acts as a low-pass filter are dependent on multiple factors including the biochemical signal frequency, flow rates and signal transporting distance in our previous study [ 20 , 22 ]. Therefore, the biochemical stimuli exposed on cells may be different from expected.…”

“…By using microfluidic platform, single yeast cells trapped via partially closed valves in response to short repeated pulses of α-factor [ 14 ], single Jurkat T cells in response to low frequency H 2 O 2 [ 15 , 16 ] and oscillatory Ca 2+ stimulus [ 17 ] in microstructure well-trapping chip. Alternatively, single adherent cells cultured on the bottom of the microfluidic channel were also investigated for their responses induced by temporal varying stimulus, such as adenosine triphosphate (ATP) pulse stimulus on NIH-3T3 cells [ 18 ], HeLa cells [ 19 ] and human umbilical vein vessel endothelial cells (HUVECs) [ 20 ], as well as a brief bacterial lipase pulses on single macrophage cell [ 21 ]. Nevertheless, there are two issues to be considered carefully in the study of dynamic external stimuli-induced cell responses in microfluidic channels.…”

An arduino-based sensor to measure transendothelial electrical resistance

“…More importantly, microfluidics allows for the introduction of flow-based shear stress, which is known to mechanically couple blood-flow to endothelial function 9,10 . Although numerous microfluidic designs for endothelial studies have been reported in the past two decades, most of them applied a 2D extracellular matrix (ECM; e.g., a coated layer of collagen and/or fibronectin) for the cells, without considering the possible 3D structures of the native ECM [11][12][13][14][15][16][17] . In vivo, endothelial cells rest on a 3D surface called the basement membrane (BM), which lines blood vessels 18 .…”

A Low-Cost, Rapidly Integrated Debubbler (RID) Module for Microfluidic Cell Culture Applications

“…Key practical features of the RID module include (i) an accessible fabrication process with rapid assembly (<2 min), (ii) low device cost (<$0.50 at lab prototype level), and (iii) press-to-fit tubing connections to simplify component integration. Controlled shear stimulation of cultured cells is a hallmark capability in microfluidic systems that enables quantitative correlation between applied fluid-induced wall shear stresses (WSS) and cellular responses including endothelial cell alignment [18], calcium signaling [19], and barrier formation [20,21]. Thus, we validated RID performance by characterizing bubble removal capabilities ranging from nanoliter to microliter volume bubbles at flow rates required to apply physiological WSS to cultured mammalian cells within standard geometry microfluidic channels.…”