A microfluidic-based investigation of bacterial attachment in ureteral stents
A microfluidic-based investigation of bacterial attachment in ureteral stents
Obstructions of the ureter lumen can originate from intrinsic or extrinsic factors, such as kidney stones, tumours, or strictures. These can affect the physiological flow of urine from the kidneys to the bladder, potentially causing infection, pain, and kidney failure. To overcome these complications, ureteral stents are often deployed clinically in order to temporarily re-establish urinary flow. Despite their clinical benefits, stents are prone to encrustation and biofilm formation that lead to reduced quality of life for patients; however, the mechanisms underlying the formation of crystalline biofilms in stents are not yet fully understood. In this study, we developed microfluidic-based devices replicating the urodynamic field within different configurations of an occluded and stented ureter. We employed computational fluid dynamic simulations to characterise the flow dynamic field within these models and investigated bacterial attachment (Pseudomonas fluorescens) by means of crystal violet staining and fluorescence microscopy. We identified the presence of hydrodynamic cavities in the vicinity of a ureteric occlusion, which were characterised by low levels of wall shear stress (WSS < 40 mPa), and observed that initiation of bacterial attachment occurred in these specific regions of the stented ureter. Notably, the bacterial coverage area was directly proportional to the number of cavities present in the model. Fluorescence microscopy confirmed that the number density of bacteria was greater within cavities (3 bacteria•mm
-2) when compared to side-holes of the stent (1 bacterium•mm
-2) or its luminal surface (0.12 bacteria•mm
-2). These findings informed the design of a novel technological solution against bacterial attachment, which reduces the extent of cavity flow and increases wall shear stress over the stent's surface.
Bacterial attachment, Biofilm formation, CFD simulations, Cavity flow, Microfluidics, Stent-on-a-chip, Ureteral obstruction, Ureteral stent, Wall shear stress
1-13
De Grazia, Antonio
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Lutheryn, Gareth, William Edward
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Meghdadi, Alireza
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Mosayyebi, Ali
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Espinosa-Ortiz, Erika J.
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Gerlach, Robin
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Carugo, Dario
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April 2020
De Grazia, Antonio
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Lutheryn, Gareth, William Edward
90e2ecc4-745e-4fe1-b109-77cfed5317bf
Meghdadi, Alireza
2f3003a8-1b77-4763-9657-19a72b04c728
Mosayyebi, Ali
ab9cf6da-58c4-4441-993b-7d03d5d3549a
Espinosa-Ortiz, Erika J.
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Gerlach, Robin
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Carugo, Dario
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De Grazia, Antonio, Lutheryn, Gareth, William Edward, Meghdadi, Alireza, Mosayyebi, Ali, Espinosa-Ortiz, Erika J., Gerlach, Robin and Carugo, Dario
(2020)
A microfluidic-based investigation of bacterial attachment in ureteral stents.
Micromachines, 11 (4), , [408].
(doi:10.3390/mi11040408).
Abstract
Obstructions of the ureter lumen can originate from intrinsic or extrinsic factors, such as kidney stones, tumours, or strictures. These can affect the physiological flow of urine from the kidneys to the bladder, potentially causing infection, pain, and kidney failure. To overcome these complications, ureteral stents are often deployed clinically in order to temporarily re-establish urinary flow. Despite their clinical benefits, stents are prone to encrustation and biofilm formation that lead to reduced quality of life for patients; however, the mechanisms underlying the formation of crystalline biofilms in stents are not yet fully understood. In this study, we developed microfluidic-based devices replicating the urodynamic field within different configurations of an occluded and stented ureter. We employed computational fluid dynamic simulations to characterise the flow dynamic field within these models and investigated bacterial attachment (Pseudomonas fluorescens) by means of crystal violet staining and fluorescence microscopy. We identified the presence of hydrodynamic cavities in the vicinity of a ureteric occlusion, which were characterised by low levels of wall shear stress (WSS < 40 mPa), and observed that initiation of bacterial attachment occurred in these specific regions of the stented ureter. Notably, the bacterial coverage area was directly proportional to the number of cavities present in the model. Fluorescence microscopy confirmed that the number density of bacteria was greater within cavities (3 bacteria•mm
-2) when compared to side-holes of the stent (1 bacterium•mm
-2) or its luminal surface (0.12 bacteria•mm
-2). These findings informed the design of a novel technological solution against bacterial attachment, which reduces the extent of cavity flow and increases wall shear stress over the stent's surface.
Text
micromachines-11-00408 (1)
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More information
Accepted/In Press date: 10 April 2020
e-pub ahead of print date: 14 April 2020
Published date: April 2020
Additional Information:
Funding Information:
Funding: This research was funded by a National Biofilms Innovation Centre (NBIC) proof-of-concept grant. The National Biofilms Innovation Centre is an Innovation Knowledge Centre (IKC) jointly funded by Biotechnology and Biological Sciences Research Council (BBSRC), Innovate UK, and the Hartree Centre.
Publisher Copyright:
© 2020 by the authors.
Keywords:
Bacterial attachment, Biofilm formation, CFD simulations, Cavity flow, Microfluidics, Stent-on-a-chip, Ureteral obstruction, Ureteral stent, Wall shear stress
Identifiers
Local EPrints ID: 439427
URI: http://eprints.soton.ac.uk/id/eprint/439427
ISSN: 2072-666X
PURE UUID: 106fbff1-1255-47d8-9506-71a78b00080c
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Date deposited: 22 Apr 2020 16:32
Last modified: 16 Apr 2024 01:51
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Contributors
Author:
Ali Mosayyebi
Author:
Erika J. Espinosa-Ortiz
Author:
Robin Gerlach
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