1
|
Qi X, Ma S, Jiang X, Wu H, Zheng J, Wang S, Han K, Zhang T, Gao J, Li X. Single-cell characterization of deformation and dynamics of mesenchymal stem cells in microfluidic systems: A computational study. Phys Rev E 2023; 108:054402. [PMID: 38115453 DOI: 10.1103/physreve.108.054402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 10/13/2023] [Indexed: 12/21/2023]
Abstract
Understanding the homing dynamics of individual mesenchymal stem cells (MSCs) in physiologically relevant microenvironments is crucial for improving the efficacy of MSC-based therapies for therapeutic and targeting purposes. This study investigates the passive homing behavior of individual MSCs in micropores that mimic interendothelial clefts through predictive computational simulations informed by previous microfluidic experiments. Initially, we quantified the size-dependent behavior of MSCs in micropores and elucidated the underlying mechanisms. Subsequently, we analyzed the shape deformation and traversal dynamics of each MSC. In addition, we conducted a systematic investigation to understand how the mechanical properties of MSCs impact their traversal process. We considered geometric and mechanical parameters, such as reduced cell volume, cell-to-nucleus diameter ratio, and cytoskeletal prestress states. Furthermore, we quantified the changes in the MSC traversal process and identified the quantitative limits in their response to variations in micropore length. Taken together, the computational results indicate the complex dynamic behavior of individual MSCs in the confined microflow. This finding offers an objective way to evaluate the homing ability of MSCs in an interendothelial-slit-like microenvironment.
Collapse
Affiliation(s)
- Xiaojing Qi
- Department of Engineering Mechanics and Center for X-Mechanics, Zhejiang University, Hangzhou 310027, China
| | - Shuhao Ma
- Department of Engineering Mechanics and Center for X-Mechanics, Zhejiang University, Hangzhou 310027, China
| | - Xinchi Jiang
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310027, China
| | - Honghui Wu
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310027, China
| | - Juanjuan Zheng
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310027, China
| | - Shuo Wang
- Department of Engineering Mechanics and Center for X-Mechanics, Zhejiang University, Hangzhou 310027, China
| | - Keqin Han
- Department of Engineering Mechanics and Center for X-Mechanics, Zhejiang University, Hangzhou 310027, China
| | - Tianyuan Zhang
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310027, China
| | - Jianqing Gao
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310027, China
| | - Xuejin Li
- Department of Engineering Mechanics and Center for X-Mechanics, Zhejiang University, Hangzhou 310027, China
| |
Collapse
|
2
|
Barrasa-Ramos S, Dessalles CA, Hautefeuille M, Barakat AI. Mechanical regulation of the early stages of angiogenesis. J R Soc Interface 2022; 19:20220360. [PMID: 36475392 PMCID: PMC9727679 DOI: 10.1098/rsif.2022.0360] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Favouring or thwarting the development of a vascular network is essential in fields as diverse as oncology, cardiovascular disease or tissue engineering. As a result, understanding and controlling angiogenesis has become a major scientific challenge. Mechanical factors play a fundamental role in angiogenesis and can potentially be exploited for optimizing the architecture of the resulting vascular network. Largely focusing on in vitro systems but also supported by some in vivo evidence, the aim of this Highlight Review is dual. First, we describe the current knowledge with particular focus on the effects of fluid and solid mechanical stimuli on the early stages of the angiogenic process, most notably the destabilization of existing vessels and the initiation and elongation of new vessels. Second, we explore inherent difficulties in the field and propose future perspectives on the use of in vitro and physics-based modelling to overcome these difficulties.
Collapse
Affiliation(s)
- Sara Barrasa-Ramos
- LadHyX, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
| | - Claire A. Dessalles
- LadHyX, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
| | - Mathieu Hautefeuille
- Laboratoire de Biologie du Développement (UMR7622), Institut de Biologie Paris Seine, Sorbonne Université, Paris, France,Facultad de Ciencias, Universidad Nacional Autónoma de México, CDMX, Mexico
| | - Abdul I. Barakat
- LadHyX, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
| |
Collapse
|
3
|
Lu M, Kanne CK, Reddington RC, Lezzar DL, Sheehan VA, Shevkoplyas SS. Concurrent Assessment of Deformability and Adhesiveness of Sickle Red Blood Cells by Measuring Perfusion of an Adhesive Artificial Microvascular Network. Front Physiol 2021; 12:633080. [PMID: 33995119 PMCID: PMC8113687 DOI: 10.3389/fphys.2021.633080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 04/06/2021] [Indexed: 12/12/2022] Open
Abstract
Biomarker development is a key clinical research need in sickle cell disease (SCD). Hemorheological parameters are excellent candidates as abnormal red blood cell (RBC) rheology plays a critical role in SCD pathophysiology. Here we describe a microfluidic device capable of evaluating RBC deformability and adhesiveness concurrently, by measuring their effect on perfusion of an artificial microvascular network (AMVN) that combines microchannels small enough to require RBC deformation, and laminin (LN) coating on channel walls to model intravascular adhesion. Each AMVN device consists of three identical capillary networks, which can be coated with LN (adhesive) or left uncoated (non-adhesive) independently. The perfusion rate for sickle RBCs in the LN-coated networks (0.18 ± 0.02 nL/s) was significantly slower than in non-adhesive networks (0.20 ± 0.02 nL/s), and both were significantly slower than the perfusion rate for normal RBCs in the LN-coated networks (0.22 ± 0.01 nL/s). Importantly, there was no overlap between the ranges of perfusion rates obtained for sickle and normal RBC samples in the LN-coated networks. Interestingly, treatment with poloxamer 188 decreased the perfusion rate for sickle RBCs in LN-coated networks in a dose-dependent manner, contrary to previous studies with conventional assays, but in agreement with the latest clinical trial which showed no clinical benefit. Overall, these findings suggest the potential utility of the adhesive AMVN device for evaluating the effect of novel curative and palliative therapies on the hemorheological status of SCD patients during clinical trials and in post-market clinical practice.
Collapse
Affiliation(s)
- Madeleine Lu
- Department of Biomedical Engineering, University of Houston, Houston, TX, United States
| | - Celeste K Kanne
- Division of Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Riley C Reddington
- Department of Biomedical Engineering, University of Houston, Houston, TX, United States
| | - Dalia L Lezzar
- Department of Biomedical Engineering, University of Houston, Houston, TX, United States
| | - Vivien A Sheehan
- Division of Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Sergey S Shevkoplyas
- Department of Biomedical Engineering, University of Houston, Houston, TX, United States
| |
Collapse
|
4
|
Piety NZ, Stutz J, Yilmaz N, Xia H, Yoshida T, Shevkoplyas SS. Microfluidic capillary networks are more sensitive than ektacytometry to the decline of red blood cell deformability induced by storage. Sci Rep 2021; 11:604. [PMID: 33436749 PMCID: PMC7804960 DOI: 10.1038/s41598-020-79710-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 12/11/2020] [Indexed: 12/15/2022] Open
Abstract
Ektacytometry has been the primary method for evaluating deformability of red blood cells (RBCs) in both research and clinical settings. This study was designed to test the hypothesis that the flow of RBCs through a network of microfluidic capillaries could provide a more sensitive assessment of the progressive impairment of RBC deformability during hypothermic storage than ektacytometry. RBC units (n = 9) were split in half, with one half stored under standard (normoxic) conditions and the other half stored hypoxically, for up to 6 weeks. RBC deformability was measured weekly using two microfluidic devices, an artificial microvascular network (AMVN) and a multiplexed microcapillary network (MMCN), and two commercially available ektacytometers (RheoScan-D and LORRCA). By week 6, the elongation indexes measured with RheoScan-D and LORRCA decreased by 5.8–7.1% (5.4–6.9% for hypoxic storage). Over the same storage duration, the AMVN perfusion rate declined by 27.5% (24.5% for hypoxic) and the MMCN perfusion rate declined by 49.0% (42.4% for hypoxic). Unlike ektacytometry, both AMVN and MMCN measurements showed statistically significant differences between the two conditions after 1 week of storage. RBC morphology deteriorated continuously with the fraction of irreversibly-damaged (spherical) cells increasing significantly faster for normoxic than for hypoxic storage. Consequently, the number of MMCN capillary plugging events and the time MMCN capillaries spent plugged was consistently lower for hypoxic than for normoxic storage. These data suggest that capillary networks are significantly more sensitive to both the overall storage-induced decline of RBC deformability, and to the differences between the two storage conditions, than ektacytometry.
Collapse
Affiliation(s)
- Nathaniel Z Piety
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Blvd, Houston, TX, 77204-5060, USA.,Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Julianne Stutz
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Blvd, Houston, TX, 77204-5060, USA
| | - Nida Yilmaz
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Blvd, Houston, TX, 77204-5060, USA
| | - Hui Xia
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Blvd, Houston, TX, 77204-5060, USA
| | | | - Sergey S Shevkoplyas
- Department of Biomedical Engineering, University of Houston, 3605 Cullen Blvd, Houston, TX, 77204-5060, USA.
| |
Collapse
|
5
|
Azimi MS, Motherwell JM, Hodges NA, Rittenhouse GR, Majbour D, Porvasnik SL, Schmidt CE, Murfee WL. Lymphatic-to-blood vessel transition in adult microvascular networks: A discovery made possible by a top-down approach to biomimetic model development. Microcirculation 2019; 27:e12595. [PMID: 31584728 DOI: 10.1111/micc.12595] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 09/09/2019] [Accepted: 10/02/2019] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Emerging areas of vascular biology focus on lymphatic/blood vessel mispatterning and the regulation of endothelial cell identity. However, a fundamental question remains unanswered: Can lymphatic vessels become blood vessels in adult tissues? Leveraging a novel tissue culture model, the objective of this study was to track lymphatic endothelial cell fate over the time course of adult microvascular network remodeling. METHODS Cultured adult Wistar rat mesenteric tissues were labeled with BSI-lectin and time-lapse images were captured over five days of serum-stimulated remodeling. Additionally, rat mesenteric tissues on day 0 and day 3 and 5 post-culture were labeled for PECAM + LYVE-1 or PECAM + podoplanin. RESULTS Cultured networks were characterized by increases in blood capillary sprouting, lymphatic sprouting, and the number of lymphatic/blood vessel connections. Comparison of images from the same network regions identified incorporation of lymphatic vessels into blood vessels. Mosaic lymphatic/blood vessels contained lymphatic marker positive and negative endothelial cells. CONCLUSIONS Our results reveal the ability for lymphatic vessels to transition into blood vessels in adult microvascular networks and discover a new paradigm for investigating lymphatic/blood endothelial cell dynamics during microvascular remodeling.
Collapse
Affiliation(s)
- Mohammad S Azimi
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
| | - Jessica M Motherwell
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA.,J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Nicholas A Hodges
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA.,J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Garret R Rittenhouse
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Dima Majbour
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Stacey L Porvasnik
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Christine E Schmidt
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Walter L Murfee
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| |
Collapse
|
6
|
Hwang Y, Candler RN. Non-planar PDMS microfluidic channels and actuators: a review. LAB ON A CHIP 2017; 17:3948-3959. [PMID: 28862708 DOI: 10.1039/c7lc00523g] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
This review examines the state of the art for manufacturing non-planar miniature channels and actuators from PDMS, where non-planar structures are defined here as those beyond simple extrusions of 2D designs, either with rounded or variable cross sections or with an emergence of the channel trajectory out-of-plane. The motivation for 3D PDMS structures and advances in their fabrication are described, focusing on geometries that were previously unachievable through conventional microfabrication. The motivation for non-planar microfluidic channels and actuators is first discussed and the existing literature is grouped into general fabrication themes and described. The structures are organized by their method of fabrication and evaluated based on their relevant properties, including the capability of producing structures with complex geometry, automation of the fabrication process, and minimum feature size. Additional properties are included for work in the more recently emerging field of non-planar PDMS actuators, where the feature size, actuation stroke, and actuation method are the key parameters of interest. In particular, this review considers the impact from recent advances in additive manufacturing, which now allow creation of truly arbitrary 3D structures down to ∼100 μm size scales.
Collapse
Affiliation(s)
- Yongha Hwang
- Department of Electro-Mechanical Systems Engineering, Korea University Sejong Campus, South Korea.
| | | |
Collapse
|
7
|
Corliss BA, Azimi MS, Munson J, Peirce SM, Murfee WL. Macrophages: An Inflammatory Link Between Angiogenesis and Lymphangiogenesis. Microcirculation 2016; 23:95-121. [PMID: 26614117 PMCID: PMC4744134 DOI: 10.1111/micc.12259] [Citation(s) in RCA: 204] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 11/23/2015] [Indexed: 12/14/2022]
Abstract
Angiogenesis and lymphangiogenesis often occur in response to tissue injury or in the presence of pathology (e.g., cancer), and it is these types of environments in which macrophages are activated and increased in number. Moreover, the blood vascular microcirculation and the lymphatic circulation serve as the conduits for entry and exit for monocyte-derived macrophages in nearly every tissue and organ. Macrophages both affect and are affected by the vessels through which they travel. Therefore, it is not surprising that examination of macrophage behaviors in both angiogenesis and lymphangiogenesis has yielded interesting observations that suggest macrophages may be key regulators of these complex growth and remodeling processes. In this review, we will take a closer look at macrophages through the lens of angiogenesis and lymphangiogenesis, examining how their dynamic behaviors may regulate vessel sprouting and function. We present macrophages as a cellular link that spatially and temporally connects angiogenesis with lymphangiogenesis, in both physiological growth and in pathological adaptations, such as tumorigenesis. As such, attempts to therapeutically target macrophages in order to affect these processes may be particularly effective, and studying macrophages in both settings will accelerate the field's understanding of this important cell type in health and disease.
Collapse
Affiliation(s)
- Bruce A. Corliss
- Department of Biomedical Engineering, 415 Lane Road, University of Virginia, Charlottesville, VA 22908
| | - Mohammad S. Azimi
- Department of Biomedical Engineering, 500 Lindy Boggs Energy Center, Tulane University, New Orleans, LA 70118
| | - Jenny Munson
- Department of Biomedical Engineering, 415 Lane Road, University of Virginia, Charlottesville, VA 22908
| | - Shayn M. Peirce
- Department of Biomedical Engineering, 415 Lane Road, University of Virginia, Charlottesville, VA 22908
| | - Walter Lee Murfee
- Department of Biomedical Engineering, 500 Lindy Boggs Energy Center, Tulane University, New Orleans, LA 70118
| |
Collapse
|
8
|
Sosa JM, Nielsen ND, Vignes SM, Chen TG, Shevkoplyas SS. The relationship between red blood cell deformability metrics and perfusion of an artificial microvascular network. Clin Hemorheol Microcirc 2015; 57:275-89. [PMID: 23603326 DOI: 10.3233/ch-131719] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The ability of red blood cells (RBC) to undergo a wide range of deformations while traversing the microvasculature is crucial for adequate perfusion. Interpretation of RBC deformability measurements performed in vitro in the context of microvascular perfusion has been notoriously difficult. This study compares the measurements of RBC deformability performed using micropore filtration and ektacytometry with the RBC ability to perfuse an artificial microvascular network (AMVN). Human RBCs were collected from healthy consenting volunteers, leukoreduced, washed and exposed to graded concentrations (0-0.08%) of glutaraldehyde (a non-specific protein cross-linker) and diamide (a spectrin-specific protein cross-linker) to impair the deformability of RBCs. Samples comprising cells with two different levels of deformability were created by adding non-deformable RBCs (hardened by exposure to 0.08% glutaraldehyde) to the sample of normal healthy RBCs. Ektacytometry indicated a nearly linear decline in RBC deformability with increasing glutaraldehyde concentration. Micropore filtration showed a significant reduction only for concentrations of glutaraldehyde higher than 0.04%. Neither micropore filtration nor ektacytometry measurements could accurately predict the AMVN perfusion. Treatment with diamide reduced RBC deformability as indicated by ektacytometry, but had no significant effect on either micropore filtration or the AMVN perfusion. Both micropore filtration and ektacytometry showed a linear decline in effective RBC deformability with increasing fraction of non-deformable RBCs in the sample. The corresponding decline in the AMVN perfusion plateaued above 50%, reflecting the innate ability of blood flow in the microvasculature to bypass occluded capillaries. Our results suggest that in vitro measurements of RBC deformability performed using either micropore filtration or ektacytometry may not represent the ability of same RBCs to perfuse microvascular networks. Further development of biomimetic tools for measuring RBC deformability (e.g. the AMVN) could enable a more functionally relevant testing of RBC mechanical properties.
Collapse
Affiliation(s)
- Jose M Sosa
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
| | - Nathan D Nielsen
- Department of Pulmonary Disease, Critical Care & Environmental Medicine, Tulane University School of Medicine, New Orleans, LA, USA
| | - Seth M Vignes
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
| | - Tanya G Chen
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
| | | |
Collapse
|
9
|
Piety NZ, Gifford SC, Yang X, Shevkoplyas SS. Quantifying morphological heterogeneity: a study of more than 1 000 000 individual stored red blood cells. Vox Sang 2015; 109:221-30. [PMID: 25900518 DOI: 10.1111/vox.12277] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 02/10/2015] [Accepted: 02/23/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVES The morphology of red blood cells (RBCs) deteriorates progressively during hypothermic storage. The degree of deterioration varies between individual cells, resulting in a highly heterogeneous population of cells contained within each RBC unit. Current techniques capable of categorizing the morphology of individual stored RBCs are manual, laborious and error-prone procedures that limit the number of cells that can be studied. Our objective was to create a simple, automated system for high-throughput RBC morphology classification. MATERIALS AND METHODS A simple microfluidic device, designed to enable rapid, consistent acquisition of images of optimally oriented RBCs, was fabricated using soft lithography. A custom image analysis algorithm was developed to categorize the morphology of each individual RBC in the acquired images. The system was used to determine morphology of individual RBCs in several RBC units stored hypothermically for 6-8 weeks. RESULTS The system was used to automatically determine the distribution of cell diameter within each morphological class for >1 000 000 individual stored RBCs (speed: >10 000 cells/h; accuracy: 91·9% low resolution, 75·3% high resolution). Diameter mean and standard deviation by morphology class were as follows: discocyte 7·80 ± 0·49 μm, echinocyte 1 7·61 ± 0·63 μm, echinocyte 2 7·02 ± 0·61 μm, echinocyte 3 6·47 ± 0·42 μm, sphero-echinocyte 6·01 ± 0·26 μm, spherocyte 6·02 ± 0·27 μm, stomatocyte 1 6·95 ± 0·61 μm and stomatocyte 2 7·32 ± 0·47 μm. CONCLUSIONS The automated morphology classification procedure described in this study is significantly simpler, faster and less subjective than conventional manual procedures. The ability to evaluate the morphology of individual RBCs automatically, rapidly and in statistically significant numbers enabled us to perform the most extensive study of stored RBC morphology to date.
Collapse
Affiliation(s)
- N Z Piety
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX, USA
| | - S C Gifford
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX, USA
| | - X Yang
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX, USA
| | - S S Shevkoplyas
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX, USA
| |
Collapse
|
10
|
|
11
|
Kovarik ML, Ornoff DM, Melvin AT, Dobes NC, Wang Y, Dickinson AJ, Gach PC, Shah PK, Allbritton NL. Micro total analysis systems: fundamental advances and applications in the laboratory, clinic, and field. Anal Chem 2013; 85:451-72. [PMID: 23140554 PMCID: PMC3546124 DOI: 10.1021/ac3031543] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Michelle L. Kovarik
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Douglas M. Ornoff
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Adam T. Melvin
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Nicholas C. Dobes
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Yuli Wang
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Alexandra J. Dickinson
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Philip C. Gach
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Pavak K. Shah
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC 27599 and North Carolina State University, Raleigh, NC 27695
| | - Nancy L. Allbritton
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC 27599 and North Carolina State University, Raleigh, NC 27695
| |
Collapse
|
12
|
Lee J, Paek J, Kim J. Sucrose-based fabrication of 3D-networked, cylindrical microfluidic channels for rapid prototyping of lab-on-a-chip and vaso-mimetic devices. LAB ON A CHIP 2012; 12:2638-42. [PMID: 22699280 DOI: 10.1039/c2lc40267j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We present a new fabrication scheme for 3D-networked, cylindrical microfluidic (MF) channels based on shaping, bonding, and assembly of sucrose fibers. It is a simple, cleanroom-free, and environment-friendly method, ideal for rapid prototyping of lab-on-a-chip devices. Despite its simplicity, it can realize complex 3D MF channel architectures such as cylindrical tapers, internal loops, end-to-side junctions, tapered junctions, and stenosis. The last two will be of special use for realizing vaso-mimetic MF structures. It also enables molding with polymers incompatible with high-temperature processing.
Collapse
Affiliation(s)
- Jiwon Lee
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA
| | | | | |
Collapse
|
13
|
Forouzan O, Yang X, Sosa JM, Burns JM, Shevkoplyas SS. Spontaneous oscillations of capillary blood flow in artificial microvascular networks. Microvasc Res 2012; 84:123-32. [PMID: 22732344 DOI: 10.1016/j.mvr.2012.06.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 06/12/2012] [Accepted: 06/13/2012] [Indexed: 10/28/2022]
Abstract
Previous computational studies have suggested that the capillary blood flow oscillations frequently observed in vivo can originate spontaneously from the non-linear rheological properties of blood, without any regulatory input. Testing this hypothesis definitively in experiments involving real microvasculature has been difficult because in vivo the blood flow in capillaries is always actively controlled by the host. The objective of this study was to test the hypothesis experimentally and to investigate the relative contribution of different blood cells to the capillary blood flow dynamics under static boundary conditions and in complete isolation from the active regulatory mechanisms mediated by the blood vessels in vivo. To accomplish this objective, we passed whole blood and re-constituted blood samples (purified red blood cells suspended in buffer or in autologous plasma) through an artificial microvascular network (AMVN) comprising completely inert, microfabricated vessels with the architecture inspired by the real microvasculature. We found that the flow of blood in capillaries of the AMVN indeed oscillates with characteristic frequencies in the range of 0-0.6 Hz, which is in a very good agreement with previous computational studies and in vivo observations. We also found that the traffic of leukocytes through the network (typically neglected in computational modeling) plays an important role in generating the oscillations. This study represents the key piece of experimental evidence in support of the hypothesis that spontaneous, self-sustained oscillations of capillary blood flow can be generated solely by the non-linear rheological properties of blood flowing through microvascular networks, and provides an insight into the mechanism of this fundamentally important microcirculatory phenomenon.
Collapse
Affiliation(s)
- Omid Forouzan
- Department of Biomedical Engineering, Tulane University, New Orleans, LA 70118, United States
| | | | | | | | | |
Collapse
|
14
|
Song JW, Bazou D, Munn LL. Anastomosis of endothelial sprouts forms new vessels in a tissue analogue of angiogenesis. Integr Biol (Camb) 2012; 4:857-62. [PMID: 22673771 DOI: 10.1039/c2ib20061a] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Here we describe a microfluidic device that accurately reproduces the dynamics of vascular anastomosis, the process by which vascular sprouts connect to achieve perfusion during angiogenesis. The micro-device features two parallel endothelial cell-lined vessel analogues separated by a 300 μm wide collagenous matrix into which the vessels can sprout and form perfused bridging connections. By accurately recapitulating anastomosis in vitro, the device will enable a new generation of studies of the mechanisms of angiogenesis and provide a novel and practical platform for drug screening.
Collapse
Affiliation(s)
- Jonathan W Song
- Edwin L. Steele Laboratory for Tumour Biology, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | | | | |
Collapse
|
15
|
Abstract
In vitro studies of vascular physiology have traditionally relied on cultures of endothelial cells, smooth muscle cells, and pericytes grown on centimeter-scale plates, filters, and flow chambers. The introduction of microfluidic tools has revolutionized the study of vascular physiology by allowing researchers to create physiologically relevant culture models, at the same time greatly reducing the consumption of expensive reagents. By taking advantage of the small dimensions and laminar flow inherent in microfluidic systems, recent studies have created in vitro models that reproduce many features of the in vivo vascular microenvironment with fine spatial and temporal resolution. In this review, we highlight the advantages of microfluidics in four areas: the investigation of hemodynamics on a capillary length scale, the modulation of fluid streams over vascular cells, angiogenesis induced by the exposure of vascular cells to well-defined gradients in growth factors or pressure, and the growth of microvascular networks in biomaterials. Such unique capabilities at the microscale are rapidly advancing the understanding of microcirculatory dynamics, shear responses, and angiogenesis in health and disease as well as the ability to create in vivo-like blood vessels in vitro.
Collapse
Affiliation(s)
- Keith H K Wong
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, USA
| | | | | | | |
Collapse
|
16
|
Kovarik ML, Gach PC, Ornoff DM, Wang Y, Balowski J, Farrag L, Allbritton NL. Micro total analysis systems for cell biology and biochemical assays. Anal Chem 2012; 84:516-40. [PMID: 21967743 PMCID: PMC3264799 DOI: 10.1021/ac202611x] [Citation(s) in RCA: 180] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Michelle L. Kovarik
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Phillip C. Gach
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Douglas M. Ornoff
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Yuli Wang
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Joseph Balowski
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Lila Farrag
- School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Nancy L. Allbritton
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC 27599 and North Carolina State University, Raleigh, NC 27695
| |
Collapse
|
17
|
Burns JM, Yang X, Forouzan O, Sosa JM, Shevkoplyas SS. Artificial microvascular network: a new tool for measuring rheologic properties of stored red blood cells. Transfusion 2011; 52:1010-23. [PMID: 22043858 DOI: 10.1111/j.1537-2995.2011.03418.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND The progressive deterioration of red blood cell (RBC) rheologic properties during refrigerated storage may reduce the clinical efficacy of transfusion of older units. STUDY DESIGN AND METHODS This article describes the development of a microfluidic device designed to test the rheologic properties of stored RBCs by measuring their ability to perfuse an artificial microvascular network (AMVN) comprised of capillary-size microchannels arranged in a pattern inspired by the real microvasculature. In the AMVN device, the properties of RBCs are evaluated by passing a 40% hematocrit suspension of RBCs through the network and measuring the overall perfusion rate. RESULTS The sensitivity of the AMVN device to the storage-induced change in rheologic properties of RBCs was tested using five prestorage leukoreduced RBC units stored in AS-1 for 41 days. The AMVN perfusion rate for stored RBCs was 26 ± 4% (19%-30%) lower than for fresh RBCs. Washing these stored RBCs in saline improved their performance by 41 ± 6% (the AMVN perfusion rate for washed stored RBCs was still 15 ± 2% lower than for fresh RBCs). CONCLUSIONS The measurements performed using the AMVN device confirm a significant decline in the rheologic properties of RBCs in units nearing expiration and demonstrate the sensitivity of the device to these storage-induced changes. The AMVN device may be useful for testing the effect of new storage conditions, additive solutions, and rejuvenation strategies on the rheologic properties of stored RBCs in vitro.
Collapse
Affiliation(s)
- Jennie M Burns
- Department of Biomedical Engineering, Tulane University, New Orleans, LA 70118, USA
| | | | | | | | | |
Collapse
|
18
|
Yang X, Forouzan O, Burns JM, Shevkoplyas SS. Traffic of leukocytes in microfluidic channels with rectangular and rounded cross-sections. LAB ON A CHIP 2011; 11:3231-40. [PMID: 21847500 DOI: 10.1039/c1lc20293f] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Traffic of leukocytes in microvascular networks (particularly through arteriolar bifurcations and venular convergences) affects the dynamics of capillary blood flow, initiation of leukocyte adhesion during inflammation, and localization and development of atherosclerotic plaques in vivo. Recently, a growing research effort has been focused on fabricating microvascular networks comprising artificial vessels with more realistic, rounded cross-sections. This paper investigated the impact of the cross-sectional geometry of microchannels on the traffic of leukocytes flowing with human whole blood through a non-symmetrical bifurcation that consisted of a 50 μm mother channel bifurcating into 30 μm and 50 μm daughter branches. Two versions of the same bifurcation comprising microchannels with rectangular and rounded cross-sections were fabricated using conventional multi-layer photolithography to produce rectangular microchannles that were then rounded in situ using a recently developed method of liquid PDMS/air bubble injection. For microchannels with rounded cross-sections, about two-thirds of marginated leukocytes traveling along a path in the top plane of the bifurcation entered the smallest 30 μm daughter branch. This distribution was reversed in microchannels with rectangular cross-sections--the majority of leukocytes traveling along a similar path continued to follow the 50 μm microchannels after the bifurcation. This dramatic difference in the distribution of leukocyte traffic among the branches of the bifurcation can be explained by preferential margination of leukocytes towards the corners of the 50 μm mother microchannels with rectangular cross-sections, and by the additional hindrance to leukocyte entry created by the sharp transition from the 50 μm mother microchannel to the 30 μm daughter branch at the intersection. The results of this study suggest that the trajectories of marginated leukocytes passing through non-symmetrical bifurcations are significantly affected by the cross-sectional geometry of microchannels and emphasize the importance of using microfludic systems with geometrical configurations closely matching physiological configurations when modeling the dynamics of whole blood flow in the microcirculation.
Collapse
Affiliation(s)
- Xiaoxi Yang
- Department of Biomedical Engineering, Tulane University, New Orleans, LA 70118, USA
| | | | | | | |
Collapse
|