Orbitally shaken shallow fluid layers. II. An improved wall shear stress model

Alpresa, Paola; Sherwin, Spencer J.; Weinberg, Peter D.; Reeuwijk, Maarten van

doi:10.1063/1.5016343

Cited by 17 publications

(20 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…is uniform throughout the well, unaffected by its side walls and independent of the starting height of the fluid. All three of these properties are incorrect [ [29] , [30] , [31] ] and the calculated WSS magnitude can be in error by an order of magnitude [ [31] , [32] , [33] ].…”

Section: Characterisation Of Flow In Swirling Wellsmentioning

confidence: 99%

“…An improved approach has recently been presented by Alpresa et al [ 31 , 34 ]. Termed the potential theory-Stokes (PT-Stokes) model, it divides the fluid into two layers.…”

Section: Characterisation Of Flow In Swirling Wellsmentioning

confidence: 99%

“…Termed the potential theory-Stokes (PT-Stokes) model, it divides the fluid into two layers. The upper layer is modelled using potential flow [ 31 ] (i.e. the fluid is assumed to be frictionless and individual elements in it do not rotate).…”

Section: Characterisation Of Flow In Swirling Wellsmentioning

confidence: 99%

“…Starting with the work of Berson et al [ 35 ], numerical models of the orbital shaker system [ [30] , [31] , [32] , 34 , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] ] have shown that WSS magnitude fluctuates with time, more so towards the edge of the well than at its centre, and that TAWSS is also greater towards the edge. Additionally, the direction of the instantaneous WSS vector rotates evenly through 360° at the centre of the well during each orbit whereas at the edge, vectors tend only to switch between forward and backward orientations along a line that is approximately parallel to the wall.…”

Section: Characterisation Of Flow In Swirling Wellsmentioning

confidence: 99%

“…A set of 33 flow simulations, corresponding to cases from across the literature, has been conducted to validate the potential theory and PT-Stokes models described above [ 31 , 34 ].…”

Section: Characterisation Of Flow In Swirling Wellsmentioning

confidence: 99%

See 4 more Smart Citations

Understanding mechanobiology in cultured endothelium: A review of the orbital shaker method

Warboys¹,

Ghim²,

Weinberg

2019

Atherosclerosis

View full text Add to dashboard Cite

A striking feature of atherosclerosis is its highly non-uniform distribution within the arterial tree. This has been attributed to variation in the haemodynamic wall shear stress (WSS) experienced by endothelial cells, but the WSS characteristics that are important and the mechanisms by which they lead to disease remain subjects of intensive investigation despite decades of research. In vivo evidence suggests that multidirectional WSS is highly atherogenic. This possibility is increasingly being studied by culturing endothelial cells in wells that are swirled on an orbital shaker. The method is simple and cost effective, has high throughput and permits chronic exposure, but interpretation of the results can be difficult because the fluid mechanics are complex; hitherto, their description has largely been restricted to the engineering literature. Here we review the findings of such studies, which indicate that putatively atherogenic flow characteristics occur at the centre of the well whilst atheroprotective ones occur towards the edge, and we describe simple mathematical methods for choosing experimental variables that avoid resonance, wave breaking and uncovering of the cells. We additionally summarise a large number of studies showing that endothelium cultured at the centre of the well expresses more pro-inflammatory and fewer homeostatic genes, has higher permeability, proliferation, apoptosis and senescence, and shows more endothelial-to-mesenchymal transition than endothelium at the edge. This simple method, when correctly interpreted, has the potential to greatly increase our understanding of the homeostatic and pathogenic mechanobiology of endothelial cells and may help identify new therapeutic targets in vascular disease.

show abstract

Section: Characterisation Of Flow In Swirling Wellsmentioning

confidence: 99%

“…An improved approach has recently been presented by Alpresa et al [ 31 , 34 ]. Termed the potential theory-Stokes (PT-Stokes) model, it divides the fluid into two layers.…”

Section: Characterisation Of Flow In Swirling Wellsmentioning

confidence: 99%

Section: Characterisation Of Flow In Swirling Wellsmentioning

confidence: 99%

Section: Characterisation Of Flow In Swirling Wellsmentioning

confidence: 99%

“…A set of 33 flow simulations, corresponding to cases from across the literature, has been conducted to validate the potential theory and PT-Stokes models described above [ 31 , 34 ].…”

Section: Characterisation Of Flow In Swirling Wellsmentioning

confidence: 99%

See 3 more Smart Citations

Understanding mechanobiology in cultured endothelium: A review of the orbital shaker method

Warboys¹,

Ghim²,

Weinberg

2019

Atherosclerosis

View full text Add to dashboard Cite

show abstract

Improvement and validation of a computational model of flow in the swirling well cell culture model

Arshad

Rowland

Riemer

et al. 2021

Biotech & Bioengineering

View full text Add to dashboard Cite

Effects of fluid dynamics on cells are often studied by growing the cells on the base of cylindrical wells or dishes that are swirled on the horizontal platform of an orbital shaker.The swirling culture medium applies a shear stress to the cells that varies in magnitude and directionality from the center to the edge of the vessel. Computational fluid dynamics methods are used to simulate the flow and hence calculate shear stresses at the base of the well. The shear characteristics at each radial location are then compared with cell behavior at the same position. Previous simulations have generally ignored effects of surface tension and wetting, and results have only occasionally been experimentally validated. We investigated whether such idealized simulations are sufficiently accurate, examining a commonly-used swirling well configuration. The breaking wave predicted by earlier simulations was not seen, and the edge-to-center difference in shear magnitude (but not directionality) almost disappeared, when surface tension and wetting were included. Optical measurements of fluid height and velocity agreed well only with the computational model that incorporated surface tension and wetting. These results demonstrate the importance of including accurate fluid properties in computational models of the swirling well method.

show abstract

Modification of the swirling well cell culture model to alter shear stress metrics

Arshad

Cheng

Reeuwijk

et al. 2023

Biotech & Bioengineering

Self Cite

View full text Add to dashboard Cite

Effects of hemodynamic shear stress on endothelial cells have been extensively investigated using the “swirling well” method, in which cells are cultured in dishes or multiwell plates placed on an orbital shaker. A wave rotates around the well, producing complex patterns of shear. The method allows chronic exposure to flow with high throughput at low cost but has two disadvantages: a number of shear stress characteristics change in a broadly similar way from the center to the edge of the well, and cells at one location in the well may release mediators into the medium that affect the behavior of cells at other locations, exposed to different shears. These properties make it challenging to correlate cell properties with shear. The present study investigated simple alterations to ameliorate these issues. Flows were obtained by numerical simulation. Increasing the volume of fluid in the well‐altered dimensional but not dimensionless shear metrics. Adding a central cylinder to the base of the well‐forced fluid to flow in a square toroidal channel and reduced multidirectionality. Conversely, suspending a cylinder above the base of the well made the flow highly multidirectional. Increasing viscosity in the latter model increased the magnitude of dimensional but not dimensionless metrics. Finally, tilting the well changed the patterns of different wall shear stress metrics in different ways. Collectively, these methods allow similar flows over most of the cells cultured and/or allow the separation of different shear metrics. A combination of the methods overcomes the limitations of the baseline model.

show abstract

Orbitally shaken shallow fluid layers. II. An improved wall shear stress model

Cited by 17 publications

References 21 publications

Understanding mechanobiology in cultured endothelium: A review of the orbital shaker method

Understanding mechanobiology in cultured endothelium: A review of the orbital shaker method

Improvement and validation of a computational model of flow in the swirling well cell culture model

Modification of the swirling well cell culture model to alter shear stress metrics

Contact Info

Product

Resources

About