<p>Because dysfunctions of endothelial cells are involved in many
pathologies, <i>in vitro </i>endothelial cell models for pathophysiological and
pharmaceutical studies have been a valuable research tool. Although numerous microfluidic-based
endothelial models have been reported, they had the cells cultured on a flat
surface without considering the possible 3D structure of the native ECM. Endothelial
cells rest on the basement membrane <i>in vivo</i>, which contains an aligned
microfibrous topography. To better understand and model the cells, it is
necessary to know if and how the fibrous topography can affect endothelial functions.
With conventional fully integrated microfluidic apparatus, it is difficult to
include additional topographies in a microchannel. Therefore, we developed a
modular microfluidic system by 3D-printing and electrospinning, which enabled
easy integration and switching of desired ECM topographies. Also, with
standardized designs, the system allowed for high flow rates up to 4000 µL/min,
which covered the full shear stress range for endothelial studies. We found that
the aligned fibrous topography on the ECM altered arginine metabolism in
endothelial cells, and thus increased nitric oxide production. To the best of
our knowledge, this is the most versatile endothelial model that has been
reported, and the new knowledge generated thereby lays a groundwork for future
endothelial research and modeling. </p>
The development of a fully integrated 3D printed electrochemical platform and its application to investigate the chemical reaction between carbon dioxide and hydrazine
