Microfluidic models of physiological or pathological flow shear stress for cell biology, disease modeling and drug development

Shear stress of physiological flows in the human body plays a critical role in maintaining the structure and functions of single cells and multicellular organs. Recently, the wide-spreading microfluidic technologies have made significant contributions to the in-vitro recapitulation of complex biochemical and mechanical cues. Microfluidic approaches are of inherent advantages in modeling of flow shear stress (FSS) because they can i) precisely modulate the type, magnitude and exposure time of FSS, ii) control the biochemical microenvironment for cell culture, and iii) be integrated with advanced microscopy techniques to enable real-time and high-resolution imaging of cell response to FSS. Here we review the microfluidic FSS models developed in the past years. We firstly introduce the various physiological flows existing in human bodies, then discuss how microfluidics modeled FSS in vitro, and finally elaborate on applications of these models in cell biology, disease modeling and drug development.