Calcium response of spatially arranged cell networks to shear stress by confined single cell patterned microfluidic...

Osteoblasts in multicellular organisms are sensitive to fluid shear stress (Fss) and respond smartly with versatile patterns of intracellular calcium signal ([Ca²⁺]_i). In this study, a spatial-single cell patterning method was developed by combining micro-contact printing (μCP) and reversible microfluidic chip mounted with vacuum together. Based on this well-defined patterning platform, it's possible to investigate calcium response to Fss modulated by spatial factors, and to characterize multiple calcium patterns quantitatively in terms of cell spacing and cell orientation. The result showed that the Fss-induced [Ca²⁺]_i profiles revealed oscillational signal patterns in non-connected cells such as those in physical-contacted cells. Close-arrayed osteoblasts showed remarkably more [Ca²⁺]_i oscillations than sparse-arrayed cells. The circular shape of the cells was sensitive to oscillational [Ca²⁺]_i as a potential major cause. The consistency of cell orientation and shear stress promoted temporal homogeneity of calcium oscillations.