Revisiting hemodynamics and blood oxygenation in a microfluidic microvasculature replica.

The complexity of microvascular circulation has led to the development of advanced imaging techniques and biomimetic models. This study developed a multifaceted microfluidic-based microdevice as an in vitro model of microvasculature to replicate important geometric and functional features of in vivo perfusion in mice. The microfluidic device consisted of a microchannel for blood perfusion, mirroring the natural hierarchical branching vascular structures found in mice. Additionally, the device incorporated a steady gradient of oxygen (O 2) which diffused through the polydimethylsiloxane (PDMS) layer, allowing for dynamic blood oxygenation. The assembled multi-layered microdevice was accompanied by a dual-modal imaging system that combined laser speckle contrast imaging (LSCI) and intrinsic signal optical imaging (ISOI) to visualize full-field blood flow distributions and blood O 2 profiles. By closely reproducing in vivo blood perfusion and oxygenation conditions, this microvasculature model, in conjunction with numerical simulation results, can provide quantitative information on physiologically relevant hemodynamics and key O 2 transport parameters that are not directly measurable in traditional animal studies. [Display omitted] • Microfluidic device was developed as an in vitro model of microvasculature. • Microchannel design was directly derived from realistic in vivo vascular geometries. • Oxygen gradient was coordinated with blood flow in the microdevice via gas diffusion. • Dual-modal system combines LSCI and ISOI for blood flow and oxygen profile imaging. • The replica can provide comparable hemodynamics and O 2 transport behavior as in vivo. [ABSTRACT FROM AUTHOR]