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Ajavon F, Coisy F, Grau-Mercier L, Fontaine J, Perez Martin A, Claret PG, Bobbia X. ARTERIAL DIAMETER VARIATIONS AS A NEW INDEX FOR STROKE VOLUME ASSESSMENT: AN EXPERIMENTAL STUDY ON A CONTROLLED HEMORRHAGIC SHOCK MODEL IN PIGLETS. Shock 2023; 59:637-645. [PMID: 36669228 DOI: 10.1097/shk.0000000000002085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
ABSTRACT Background: The assessment of cardiac output (CO) is a major challenge during shock. The criterion standard for CO evaluation is transpulmonary thermodilution, which is an invasive technique. Speckle tracking is an automatized method of analyzing tissue motion using echography. This tool can be used to monitor pulsed arterial diameter variations with low interobserver variability. An experimental model of controlled hemorrhagic shock allows for multiple CO variations. The main aim of this study is to show the correlation between the femoral arterial diameter variations (fADVs) and the stroke volume (SV) measured by thermodilution during hemorrhagic shock management and the resuscitation of anesthetized piglets. The secondary objective is to explore the respective correlations between SV and subaortic time-velocity index, abdominal aorta ADV, carotid ADV, and subclavian ADV. Methods : Piglets were bled until mean arterial pressure reached 40 mm Hg. Controlled hemorrhage was maintained for 30 minutes before randomizing the piglets to three resuscitation groups-the fluid-filling group (reanimated with saline solution only), NEph group (norepinephrine + saline solution), and Eph group (epinephrin + saline solution). Speckle tracking, echocardiographic, and hemodynamic measures were performed at different stages of the protocol. Results : Thirteen piglets were recruited and included for statistical analysis. Of all the piglets, 164 fADV measures were attempted and 160 were successful (98%). The correlation coefficient between fADV and SV was 0.71 (95% confidence interval [CI], 0.62 to 0.78; P < 0.01). The correlation coefficient between SV and abdominal aorta ADV, subclavian ADV, and carotid ADV was 0.30 (95% CI, 0.13 to 0.46; P < 0.01), 0.56 (95% CI, 0.45 to 0.66, P < 0.01), and 0.15 (95% CI, -0.01 to 0.30, P = 0.06), respectively. Conclusions : In this hemorrhagic shock model using piglets, fADV was strongly correlated with SV.
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Affiliation(s)
| | | | | | - Jules Fontaine
- Department of Anesthesiology, Emergency and Critical Care Medicine, Intensive Care Unit, Nîmes University Hospital, Montpellier University, Nîmes, France
| | | | - Pierre-Géraud Claret
- Department of Anesthesiology, Emergency and Critical Care Medicine, Intensive Care Unit, Nîmes University Hospital, Montpellier University, Nîmes, France
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Neumann EE, Doherty S, Bena J, Erdemir A. Role of multi-layer tissue composition of musculoskeletal extremities for prediction of in vivo surface indentation response and layer deformations. PLoS One 2023; 18:e0284721. [PMID: 37083580 PMCID: PMC10121013 DOI: 10.1371/journal.pone.0284721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 04/05/2023] [Indexed: 04/22/2023] Open
Abstract
Emergent mechanics of musculoskeletal extremities (surface indentation stiffness and tissue deformation characteristics) depend on the underlying composition and mechanics of each soft tissue layer (i.e. skin, fat, and muscle). Limited experimental studies have been performed to explore the layer specific relationships that contribute to the surface indentation response. The goal of this study was to examine through statistical modeling how the soft tissue architecture contributed to the aggregate mechanical surface response across 8 different sites of the upper and lower extremities. A publicly available dataset was used to examine the relationship of soft tissue thickness (fat and muscle) to bulk tissue surface compliance. Models required only initial tissue layer thicknesses, making them usable in the future with only a static ultrasound image. Two physics inspired models (series of linear springs), which allowed reduced statistical representations (combined locations and location specific), were explored to determine the best predictability of surface compliance and later individual layer deformations. When considering the predictability of the experimental surface compliance, the physics inspired combined locations model showed an improvement over the location specific model (percent difference of 25.4 +/- 27.9% and 29.7 +/- 31.8% for the combined locations and location specific models, respectively). While the statistical models presented in this study show that tissue compliance relies on the individual layer thicknesses, it is clear that there are other variables that need to be accounted for to improve the model. In addition, the individual layer deformations of fat and muscle tissues can be predicted reasonably well with the physics inspired models, however additional parameters may improve the robustness of the model outcomes, specifically in regard to capturing subject specificity.
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Affiliation(s)
- Erica E Neumann
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America
- Computational Biomodeling (CoBi) Core, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America
| | - Sean Doherty
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America
- Computational Biomodeling (CoBi) Core, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America
| | - James Bena
- Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH, United States of America
| | - Ahmet Erdemir
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America
- Computational Biomodeling (CoBi) Core, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America
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Abstract
PURPOSE OF REVIEW Aging is an important risk factor for cardiovascular disease and is associated with increased vessel wall stiffness. Pathophysiological stiffening, notably in arteries, disturbs the integrity of the vascular endothelium and promotes permeability and transmigration of immune cells, thereby driving the development of atherosclerosis and related vascular diseases. Effective therapeutic strategies for arterial stiffening are still lacking. RECENT FINDINGS Here, we overview the literature on age-related arterial stiffening, from patient-derived data to preclinical in-vivo and in-vitro findings. First, we overview the common techniques that are used to measure stiffness and discuss the observed stiffness values in atherosclerosis and aging. Next, the endothelial response to stiffening and possibilities to attenuate this response are discussed. SUMMARY Future research that will define the endothelial contribution to stiffness-related cardiovascular disease may provide new targets for intervention to restore endothelial function in atherosclerosis and complement the use of currently applied lipid-lowering, antihypertensive, and anti-inflammatory drugs.
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Affiliation(s)
- Aukie Hooglugt
- Amsterdam UMC, University of Amsterdam, Department of Medical Biochemistry, Amsterdam Cardiovascular Sciences
- Amsterdam UMC, VU University Medical Center, Department of Physiology, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Olivia Klatt
- Amsterdam UMC, University of Amsterdam, Department of Medical Biochemistry, Amsterdam Cardiovascular Sciences
| | - Stephan Huveneers
- Amsterdam UMC, University of Amsterdam, Department of Medical Biochemistry, Amsterdam Cardiovascular Sciences
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Ho E, Mulorz J, Wong J, Wagenhäuser MU, Tsao PS, Ramasubramanian AK, Lee SJJ. Nicotine Affects Murine Aortic Stiffness and Fatigue Response During Supraphysiological Cycling. J Biomech Eng 2022; 144:1114460. [PMID: 34244728 PMCID: PMC8420792 DOI: 10.1115/1.4051706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Indexed: 01/03/2023]
Abstract
Nicotine exposure is a major risk factor for several cardiovascular diseases. Although the deleterious effects of nicotine on aortic remodeling processes have been studied to some extent, the biophysical consequences are not fully elucidated. In this investigation, we applied quasi-static and dynamic loading to quantify ways in which exposure to nicotine affects the mechanical behavior of murine arterial tissue. Segments of thoracic aortas from C57BL/6 mice exposed to 25 mg/kg/day of subcutaneous nicotine for 28 days were subjected to uniaxial tensile loading in an open-circumferential configuration. Comparing aorta segments from nicotine-treated mice relative to an equal number of control counterparts, stiffness in the circumferential direction was nearly twofold higher (377 kPa ± 165 kPa versus 191 kPa ± 65 kPa, n = 5, p = 0.03) at 50% strain. Using a degradative power-law fit to fatigue data at supraphysiological loading, we observed that nicotine-treated aortas exhibited significantly higher peak stress, greater loss of tension, and wider oscillation band than control aortas (p ≤ 0.01 for all three variables). Compared to simple stress relaxation tests, fatigue cycling is shown to be more sensitive and versatile in discerning nicotine-induced changes in mechanical behavior over many cycles. Supraphysiological fatigue cycling thus may have broader potential to reveal subtle changes in vascular mechanics caused by other exogenous toxins or pathological conditions.
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Affiliation(s)
- Elizabeth Ho
- Mechanical Engineering, San José State University, One Washington Square, San José, CA 95192-0087,e-mail:
| | - Joscha Mulorz
- Department of Vascular and Endovascular Surgery, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, Moorenstraße 5, Düsseldorf 40225, Germany,e-mail:
| | - Jason Wong
- Mechanical Engineering, San José State University, One Washington Square, San José, CA 95192-0087,e-mail:
| | - Markus U. Wagenhäuser
- Department of Vascular and Endovascular Surgery, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, Moorenstraße 5, Düsseldorf 40225, Germany,e-mail:
| | - Philip S. Tsao
- Stanford University School of Medicine and VA Palo Alto Health Care System,3801 Miranda Avenue, Palo Alto, CA 94304,e-mail:
| | - Anand K. Ramasubramanian
- Chemical and Materials Engineering, San José State University, One Washington Square, San José, CA 95192-0082,e-mail:
| | - Sang-Joon John Lee
- Mechanical Engineering, San José State University, One Washington Square, San José, CA 95192-0087,e-mail:
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Bell JS, Adio AO, Pitt A, Hayman L, Thorn CE, Shore AC, Whatmore JL, Winlove CP. Microstructural Characterization of Resistance Artery Remodelling in Diabetes Mellitus. J Vasc Res 2021; 59:50-60. [PMID: 34544081 DOI: 10.1159/000517856] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 05/04/2021] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Microvascular remodelling is a symptom of cardiovascular disease. Despite the mechanical environment being recognized as a major contributor to the remodelling process, it is currently only understood in a rudimentary way. OBJECTIVE A morphological and mechanical evaluation of the resistance vasculature in health and diabetes mellitus. METHODS The cells and extracellular matrix of human subcutaneous resistance arteries from abdominal fat biopsies were imaged using two-photon fluorescence and second harmonic generation at varying transmural pressure. The results informed a two-layer mechanical model. RESULTS Diabetic resistance arteries reduced in wall area as pressure was increased. This was attributed to the presence of thick, straight collagen fibre bundles that braced the outer wall. The abnormal mechanical environment caused the internal elastic lamina and endothelial and vascular smooth muscle cell arrangements to twist. CONCLUSIONS Our results suggest diabetic microvascular remodelling is likely to be stress-driven, comprising at least 2 stages: (1) Laying down of adventitial bracing fibres that limit outward distension, and (2) Deposition of additional collagen in the media, likely due to the significantly altered mechanical environment. This work represents a step towards elucidating the local stress environment of cells, which is crucial to build accurate models of mechanotransduction in disease.
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Affiliation(s)
- James S Bell
- Department of Physics, University of Exeter, Exeter, United Kingdom.,Institute of Biomedical and Clinical Science, University of Exeter Medical School, University of Exeter, Exeter, United Kingdom.,School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Aminat O Adio
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School and NIHR Exeter Clinical Research Facility, Exeter, United Kingdom
| | - Andrew Pitt
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School and NIHR Exeter Clinical Research Facility, Exeter, United Kingdom
| | - Lindsay Hayman
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School and NIHR Exeter Clinical Research Facility, Exeter, United Kingdom
| | - Clare E Thorn
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School and NIHR Exeter Clinical Research Facility, Exeter, United Kingdom
| | - Angela C Shore
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School and NIHR Exeter Clinical Research Facility, Exeter, United Kingdom
| | - Jacqueline L Whatmore
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, University of Exeter, Exeter, United Kingdom
| | - C Peter Winlove
- Department of Physics, University of Exeter, Exeter, United Kingdom
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Shirasu T, Yodsanit N, Xie X, Zhao Y, Wang Y, Xie R, Huang Y, Wang B, Urabe G, Gong S, Guo LW, Kent KC. An adventitial painting modality of local drug delivery to abate intimal hyperplasia. Biomaterials 2021; 275:120968. [PMID: 34153787 DOI: 10.1016/j.biomaterials.2021.120968] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 06/04/2021] [Indexed: 12/29/2022]
Abstract
A major medical problem is the persistent lack of approved therapeutic methods to prevent postoperative intimal hyperplasia (IH) which leads to high-rate failure of open vascular reconstructions such as bypass grafting. Hydrogel has been widely used in preclinical trials for perivascular drug administration to mitigate postoperative IH. However, bulky hydrogel is potentially pro-inflammatory, posing a significant hurdle to clinical translation. Here we developed a new modality of directly "painting" drug-loaded unimolecular micelles (UM) to the adventitia thus obviating the need for a hydrogel. To render tissue adhesion, we generated amine-reactive unimolecular micelles with N-hydroxysuccinimide ester (UM-NHS) terminal groups to form stable amide bonds with the adventitia. To test periadventitial application, we either soaked balloon-injured rat carotid arteries in crosslinked UM-NHS (Mode-1) or non-crosslinked UM-NHS (Mode-2), or painted the vessel surface with non-crosslinked UM-NHS (Mode-3). The UM-NHS were loaded with or without a model drug (rapamycin) known to be IH inhibitory. We found that Mode-1 produced a marked IH-mitigating drug effect but also caused severe tissue damage. Mode-2 resulted in lower tissue toxicity yet less drug effect on IH. However, the painting method, Mode-3, demonstrated a pronounced therapeutic effect (75% inhibition of IH) without obvious toxicity. In summary, we present a simple painting modality of periadventitial local drug delivery using tissue-adhesive UM. Given the robust IH-abating efficacy and low tissue toxicity, this prototype merits further development towards an effective anti-stenosis therapy suitable for open vascular reconstructions.
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Affiliation(s)
- Takuro Shirasu
- Department of Surgery, School of Medicine, University of Virginia, Charlottesville, VA, 22903, USA
| | - Nisakorn Yodsanit
- Department of Biomedical Engineering, And Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, 53715, USA
| | - Xiujie Xie
- Department of Surgery, School of Medicine, University of Virginia, Charlottesville, VA, 22903, USA
| | - Yi Zhao
- Department of Biomedical Engineering, And Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, 53715, USA
| | - Yuyuan Wang
- Department of Biomedical Engineering, And Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, 53715, USA
| | - Ruosen Xie
- Department of Biomedical Engineering, And Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, 53715, USA; Department of Material Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53715, USA
| | - Yitao Huang
- Department of Surgery, School of Medicine, University of Virginia, Charlottesville, VA, 22903, USA
| | - Bowen Wang
- Department of Surgery, School of Medicine, University of Virginia, Charlottesville, VA, 22903, USA
| | - Go Urabe
- Department of Surgery, School of Medicine, University of Virginia, Charlottesville, VA, 22903, USA
| | - Shaoqin Gong
- Department of Biomedical Engineering, And Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, 53715, USA; Department of Material Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53715, USA; Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53715, USA.
| | - Lian-Wang Guo
- Department of Surgery, School of Medicine, University of Virginia, Charlottesville, VA, 22903, USA; Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA, USA.
| | - K Craig Kent
- Department of Surgery, School of Medicine, University of Virginia, Charlottesville, VA, 22903, USA.
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Kim SH, Monticone RE, McGraw KR, Wang M. Age-associated proinflammatory elastic fiber remodeling in large arteries. Mech Ageing Dev 2021; 196:111490. [PMID: 33839189 PMCID: PMC8154723 DOI: 10.1016/j.mad.2021.111490] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/24/2021] [Accepted: 04/05/2021] [Indexed: 12/12/2022]
Abstract
Elastic fibers are the main components of the extracellular matrix of the large arterial wall. Elastic fiber remodeling is an intricate process of synthesis and degradation of the core elastin protein and microfibrils accompanied by the assembly and disassembly of accessory proteins. Age-related morphological, structural, and functional proinflammatory remodeling within the elastic fiber has a profound effect upon the integrity, elasticity, calcification, amyloidosis, and stiffness of the large arterial wall. An age-associated increase in arterial stiffness is a major risk factor for the pathogenesis of diseases of the large arteries such as hypertensive and atherosclerotic vasculopathy. This mini review is an update on the key molecular, cellular, functional, and structural mechanisms of elastic fiber proinflammatory remodeling in large arteries with aging. Targeting structural and functional integrity of the elastic fiber may be an effective approach to impede proinflammatory arterial remodeling with advancing age.
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Affiliation(s)
- Soo Hyuk Kim
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institution on Aging, National Institutes of Health, Biomedical Research Center (BRC), 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Robert E Monticone
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institution on Aging, National Institutes of Health, Biomedical Research Center (BRC), 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Kimberly R McGraw
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institution on Aging, National Institutes of Health, Biomedical Research Center (BRC), 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Mingyi Wang
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institution on Aging, National Institutes of Health, Biomedical Research Center (BRC), 251 Bayview Boulevard, Baltimore, MD, 21224, USA.
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Ghadie NM, St-Pierre JP, Labrosse MR. The Contribution of Glycosaminoglycans/Proteoglycans to Aortic Mechanics in Health and Disease: A Critical Review. IEEE Trans Biomed Eng 2021; 68:3491-3500. [PMID: 33872141 DOI: 10.1109/tbme.2021.3074053] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
While elastin and collagen have received a lot of attention as major contributors to aortic biomechanics, glycosaminoglycans (GAGs) and proteoglycans (PGs) recently emerged as additional key players whose roles must be better elucidated if one hopes to predict aortic ruptures caused by aneurysms and dissections more reliably. GAGs are highly negatively charged polysaccharide molecules that exist in the extracellular matrix (ECM) of the arterial wall. In this critical review, we summarize the current understanding of the contributions of GAGs/PGs to the biomechanics of the normal aortic wall, as well as in the case of aortic diseases such as aneurysms and dissections. Specifically, we describe the fundamental swelling behavior of GAGs/PGs and discuss their contributions to residual stresses and aortic stiffness, thereby highlighting the importance of taking these polyanionic molecules into account in mathematical and numerical models of the aorta. We suggest specific lines of investigation to further the acquisition of experimental data to complement simulations and solidify our current understanding. We underscore different potential roles of GAGs/PGs in thoracic aortic aneurysm (TAAD) and abdominal aortic aneurysm (AAA). Namely, we report findings according to which the accumulation of GAGs/PGs in TAAD causes stress concentrations which may be sufficient to initiate and propagate delamination. On the other hand, there seems to be no clear indication of a relationship between the marked reduction in GAG/PG content and the stiffening and weakening of the aortic wall in AAA.
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Johnson R, Rafuse M, Selvakumar PP, Tan W. Effects of recipient age, heparin release and allogeneic bone marrow-derived stromal cells on vascular graft remodeling. Acta Biomater 2021; 125:172-182. [PMID: 33639311 DOI: 10.1016/j.actbio.2021.02.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 02/07/2023]
Abstract
Small-caliber vascular grafts are used in a wide range of clinical conditions. However, there remains a substantial unfulfilled need for readily-available, synthetic vascular grafts with high long-term patency rate. To fulfill the translational goal for bioengineered vascular grafts, important considerations for the pre-clinical evaluation include the graft design, cell incorporation and selection of an animal model. To assess the three factors, we used vascular grafts consisting of core/shell-structured microfibers of polycaprolactone/gelatin with a thin polycaprolactone overlay. The respective influences of the heparin release mode, animal age, and allogeneic bone marrow-derived stromal cells (MSCs) seeded in the lumen on the graft remodeling were assessed after four-and-half-month implantation on an interposition graft of abdominal aorta model. Except two rats dying from graft-unrelated issues, all other rats (18 out of 20) showed good graft patency upon explantation. The cell phenotype, matrix content and structure in the neotissues around the graft, as well as the flow perfusion through the graft were examined. More grafts in the aged rats showed local narrowing and flow incongruence than the other grafts in young adult rats. Compared to acellular grafts, cellular grafts showed efficient recruitment of vascular cells to form more organized structures with elastin in the vascular wall. Endothelialization and α-smooth muscle actin-positive cells were shown in all four types of vascular grafts. This study revealed the significant effects of MSC and recipient age but not heparin release pattern on graft remodeling. STATEMENT OF SIGNIFICANCE: The vascular graft is a mainstream of surgical intervention to treat vascular diseases. Currently, vascular grafts, particularly small-diameter ones, still show high failure rates. This study has evaluated the respective impacts of heparin release pattern, allogeneic bone marrow-derived stromal cell seeding, and recipient age on the long-term remodeling of vascular grafts. There is a dearth of literature which considers the recipient age as an influencing factor for vascular grafting. However, adults particularly elderly constitute the majority of vascular graft recipients in the "real" clinical environment. While juvenile animals were widely used for graft evaluations, this study involved adult animals. The study outcomes provided important implications regarding graft designs and evaluation approaches.
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Zhang Y, Huang Z, Dong S, Liu Z, Liu Y, Tang L, Cheng T, Zhou X. Evaluation of Cell's Passability in the ECM Network. Biophys J 2020; 119:1056-1064. [PMID: 32891186 DOI: 10.1016/j.bpj.2020.07.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/17/2020] [Accepted: 07/27/2020] [Indexed: 11/28/2022] Open
Abstract
The microstructure of the extracellular matrix (ECM) plays a key role in affecting cell migration, especially nonproteolytic migration. It is difficult, however, to measure some properties of the ECM, such as stiffness and the passability for cell migration. On the basis of a network model of collagen fiber in the ECM, which has been well applied to simulate mechanical behaviors such as the stress-strain relationship, damage, and failure, we proposed a series of methods to study the microstructural properties containing pore size and pore stiffness and to search for the possible migration paths for cells. Finally, with a given criterion, we quantitatively evaluated the passability of the ECM network for cell migration. The fiber network model with a microstructure and the analysis method presented in this study further our understanding of and ability to evaluate the properties of an ECM network.
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Affiliation(s)
- Yongrou Zhang
- Guangdong Key Laboratory of Modern Control Technology, Guangdong Institute of Intelligent Manufacturing, Guangzhou, Guangdong, China; School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, Guangdong, China
| | - Zetao Huang
- School of Computer Science and Engineering, South China University of Technology, Guangzhou, Guangdong, China
| | - Shoubin Dong
- School of Computer Science and Engineering, South China University of Technology, Guangzhou, Guangdong, China
| | - Zejia Liu
- School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, Guangdong, China.
| | - Yiping Liu
- School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, Guangdong, China
| | - Liqun Tang
- School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, Guangdong, China; State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou, Guangdong, China
| | - Taobo Cheng
- Guangdong Key Laboratory of Modern Control Technology, Guangdong Institute of Intelligent Manufacturing, Guangzhou, Guangdong, China
| | - Xuefeng Zhou
- Guangdong Key Laboratory of Modern Control Technology, Guangdong Institute of Intelligent Manufacturing, Guangzhou, Guangdong, China.
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Scott RA, Robinson KG, Kiick KL, Akins RE. Human Adventitial Fibroblast Phenotype Depends on the Progression of Changes in Substrate Stiffness. Adv Healthc Mater 2020; 9:e1901593. [PMID: 32105417 PMCID: PMC7274877 DOI: 10.1002/adhm.201901593] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/31/2020] [Indexed: 12/24/2022]
Abstract
Adventitial fibroblasts (AFs) are major contributors to vascular remodeling and maladaptive cascades associated with arterial disease, where AFs both contribute to and respond to alterations in their surrounding matrix. The relationships between matrix modulus and human aortic AF (AoAF) function are investigated using poly(ethylene glycol)-based hydrogels designed with matrix metalloproteinase (MMP)-sensitive and integrin-binding peptides. Initial equilibrium shear storage moduli for the substrates examined are 0.33, 1.42, and 2.90 kPa; after 42 days of culture, all hydrogels exhibit similar storage moduli (0.3-0.7 kPa) regardless of initial modulus, with encapsulated AoAFs spreading and proliferating. In 10 and 7.5 wt% hydrogels, modulus decreases monotonically throughout culture; however, in 5 wt% hydrogels, modulus increases after an initial 7 days of culture, accompanied by an increase in myofibroblast transdifferentiation and expression of collagen I and III through day 28. Thereafter, significant reductions in both collagens occur, with increased MMP-9 and decreased tissue inhibitor of metalloproteinase-1/-2 production. Releasing cytoskeletal tension or inhibiting cellular protein secretion in 5 wt% hydrogels block the stiffening of the polymer matrix. Results indicate that encapsulated AoAFs initiate cell-mediated matrix remodeling and demonstrate the utility of dynamic 3D systems to elucidate the complex interactions between cell behavior and substrate properties.
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Affiliation(s)
- Rebecca A. Scott
- Department of Materials Science and Engineering, University of Delaware, 201 DuPont, Hall, Newark, Delaware 19716, United States
- Nemours - Alfred I. duPont Hospital for Children, 1600 Rockland Road, Wilmington, Delaware 19803, United States
- Delaware Biotechnology Institute, University of Delaware, 15 Innovation Way, Newark, DE 19711, United States
| | - Karyn G. Robinson
- Nemours - Alfred I. duPont Hospital for Children, 1600 Rockland Road, Wilmington, Delaware 19803, United States
| | - Kristi L. Kiick
- Department of Materials Science and Engineering, University of Delaware, 201 DuPont, Hall, Newark, Delaware 19716, United States
- Delaware Biotechnology Institute, University of Delaware, 15 Innovation Way, Newark, DE 19711, United States
| | - Robert E. Akins
- Department of Materials Science and Engineering, University of Delaware, 201 DuPont, Hall, Newark, Delaware 19716, United States
- Nemours - Alfred I. duPont Hospital for Children, 1600 Rockland Road, Wilmington, Delaware 19803, United States
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