Open AccessA Modified Parallel Plate Flow Chamber to Study Local Endothelial Response to Recirculating Disturbed Flow
Author(s) -
Jason Sedlak,
Alisa Morss Clyne
Publication year - 2019
Publication title -
journal of biomechanical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 126
eISSN - 1528-8951
pISSN - 0148-0731
DOI - 10.1115/1.4044899
Subject(s) - laminar flow , shear stress , materials science , nitric oxide , biophysics , endothelial stem cell , flow conditions , permeability (electromagnetism) , chemistry , composite material , flow (mathematics) , biology , mechanics , biochemistry , in vitro , physics , membrane , organic chemistry
Atherosclerosis develops at arterial sites where endothelial cells (ECs) are exposed to low time-averaged shear stress, in particular in regions of recirculating disturbed flow. To understand how hemodynamics contributes to EC dysfunction in atheroma development, an in vitro parallel plate flow chamber gasket was modified with protruding baffles to produce large recirculating flow regions. Computational fluid dynamics (CFD) predicted that more than 60% of the flow surface area was below the 12 dynes/cm2 atheroprotective threshold. Bovine aortic endothelial cells (BAECs) were then seeded in the parallel plate flow chamber with either the standard laminar or the new disturbed flow gasket (DFG) and exposed to flow for 36 h. Cell morphology, nitric oxide (NO), proliferation, permeability, and monocyte adhesion were assessed by phase contrast and confocal microscopy. BAEC exposed to 20 dynes/cm2 shear stress in the laminar flow device aligned and elongated in the flow direction while increasing nitric oxide, decreasing permeability, and maintaining low proliferation and monocyte adhesion. BAEC in the recirculating flow and low shear stress disturbed flow device regions did not elongate or align, produced less nitric oxide, and showed higher proliferation, permeability, and monocyte adhesion than cells in the laminar flow device. However, cells in disturbed flow device regions exposed to atheroprotective shear stress did not consistently align or decrease permeability, and these cells demonstrated low nitric oxide levels. The new parallel plate DFG provides a means to study recirculating flow, highlighting the complex relationship between hemodynamics and endothelial function.