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Chandurkar MK, Mittal N, Royer-Weeden SP, Lehmann SD, Michels EB, Haarman SE, Severance SA, Rho Y, Han SJ. Transient low shear-stress preconditioning influences long-term endothelial traction and alignment under high shear flow. Am J Physiol Heart Circ Physiol 2024; 326:H1180-H1192. [PMID: 38457352 DOI: 10.1152/ajpheart.00067.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/01/2024] [Accepted: 03/03/2024] [Indexed: 03/10/2024]
Abstract
Endothelial cells (ECs) within the vascular system encounter fluid shear stress (FSS). High, laminar FSS promotes vasodilation and anti-inflammatory responses, whereas low or disturbed FSS induces dysfunction and inflammation. However, the adaptation of endothelial cells (ECs) to dynamically changing FSS patterns remains underexplored. Here, by combining traction force microscopy with a custom flow chamber, we examined human umbilical vein endothelial cells adapting their traction during transitions from short-term low shear to long-term high shear stress. We discovered that the initial low FSS elevates the traction by only half of the amount in response to direct high FSS even after flow changes to high FSS. However, in the long term under high FSS, the flow started with low FSS triggers a substantial second rise in traction for over 10 h. In contrast, the flow started directly with high FSS results in a quick traction surge followed by a huge reduction below the baseline traction in <30 min. Importantly, we find that the orientation of traction vectors is steered by initial shear exposure. Using Granger causality analysis, we show that the traction that aligns in the flow direction under direct high FSS functionally causes cell alignment toward the flow direction. However, EC traction that orients perpendicular to the flow that starts with temporary low FSS functionally causes cell orientation perpendicular to the flow. Taken together, our findings elucidate the significant influence of initial short-term low FSS on lasting changes in endothelial traction that induces EC alignment.NEW & NOTEWORTHY In our study, we uncover that preconditioning with low shear stress yields enduring impacts on endothelial cell traction and orientation, persisting even after transitioning to high-shear conditions. Using Granger causality analysis, we demonstrate a functional link between the direction of cell traction and subsequent cellular alignment across varying shear environments.
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Affiliation(s)
- Mohanish K Chandurkar
- Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan, United States
- Health Research Institute, Michigan Technological University, Houghton, Michigan, United States
| | - Nikhil Mittal
- Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan, United States
- Health Research Institute, Michigan Technological University, Houghton, Michigan, United States
| | - Shaina P Royer-Weeden
- Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan, United States
- Health Research Institute, Michigan Technological University, Houghton, Michigan, United States
| | - Steven D Lehmann
- Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan, United States
| | - Etienne B Michels
- Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan, United States
| | - Samuel E Haarman
- Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan, United States
- Health Research Institute, Michigan Technological University, Houghton, Michigan, United States
| | - Scott A Severance
- Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan, United States
| | - Yeonwoo Rho
- Department of Mathematical Sciences, Michigan Technological University, Houghton, Michigan, United States
| | - Sangyoon J Han
- Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan, United States
- Health Research Institute, Michigan Technological University, Houghton, Michigan, United States
- Department of Mechanical Engineering and Engineering Mechanics, Michigan Technological University, Houghton, Michigan, United States
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Ding H, Hou X, Gao Z, Guo Y, Liao B, Wan J. Challenges and Strategies for Endothelializing Decellularized Small-Diameter Tissue-Engineered Vessel Grafts. Adv Healthc Mater 2024:e2304432. [PMID: 38462702 DOI: 10.1002/adhm.202304432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/26/2024] [Indexed: 03/12/2024]
Abstract
Vascular diseases are the leading cause of ischemic necrosis in tissues and organs, necessitating using vascular grafts to restore blood supply. Currently, small vessels for coronary artery bypass grafts are unavailable in clinical settings. Decellularized small-diameter tissue-engineered vessel grafts (SD-TEVGs) hold significant potential. However, they face challenges, as simple implantation of decellularized SD-TEVGs in animals leads to thrombosis and calcification due to incomplete endothelialization. Consequently, research and development focus has shifted toward enhancing the endothelialization process of decellularized SD-TEVGs. This paper reviews preclinical studies involving decellularized SD-TEVGs, highlighting different strategies and their advantages and disadvantages for achieving rapid endothelialization of these vascular grafts. Methods are analyzed to improve the process while addressing potential shortcomings. This paper aims to contribute to the future commercial viability of decellularized SD-TEVGs.
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Affiliation(s)
- Heng Ding
- Department of Cardiovascular Surgery, The Affiliated Hospital, Southwest Medical University, Metabolic Vascular Diseases Key Laboratory of Sichuan Province, Key Laboratory of cardiovascular remodeling and dysfunction, Luzhou, Sichuan, 646000, China
- Department of Pediatrics, The Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University, Nanjing, 211166, P. R. China
| | - Xiaojie Hou
- Department of Cardiovascular Surgery and Cardiovascular Surgery Research Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Zhen Gao
- Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, 100069, China
| | - Yingqiang Guo
- Department of Cardiovascular Surgery and Cardiovascular Surgery Research Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Bin Liao
- Department of Cardiovascular Surgery, The Affiliated Hospital, Southwest Medical University, Metabolic Vascular Diseases Key Laboratory of Sichuan Province, Key Laboratory of cardiovascular remodeling and dysfunction, Luzhou, Sichuan, 646000, China
- Key Laboratory of Medical Electrophysiology, Ministry of Education & Medical Electrophysiological Key Laboratory of Sichuan Province, (Collaborative Innovation Center for Prevention of Cardiovascular Diseases), Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Juyi Wan
- Department of Cardiovascular Surgery, The Affiliated Hospital, Southwest Medical University, Metabolic Vascular Diseases Key Laboratory of Sichuan Province, Key Laboratory of cardiovascular remodeling and dysfunction, Luzhou, Sichuan, 646000, China
- Key Laboratory of Medical Electrophysiology, Ministry of Education & Medical Electrophysiological Key Laboratory of Sichuan Province, (Collaborative Innovation Center for Prevention of Cardiovascular Diseases), Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, 646000, China
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Chandurkar MK, Mittal N, Royer-Weeden SP, Lehmann SD, Rho Y, Han SJ. Low Shear in Short-Term Impacts Endothelial Cell Traction and Alignment in Long-Term. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.20.558732. [PMID: 37790318 PMCID: PMC10542130 DOI: 10.1101/2023.09.20.558732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Within the vascular system, endothelial cells (ECs) are exposed to fluid shear stress (FSS), a mechanical force exerted by blood flow that is critical for regulating cellular tension and maintaining vascular homeostasis. The way ECs react to FSS varies significantly; while high, laminar FSS supports vasodilation and suppresses inflammation, low or disturbed FSS can lead to endothelial dysfunction and increase the risk of cardiovascular diseases. Yet, the adaptation of ECs to dynamically varying FSS remains poorly understood. This study focuses on the dynamic responses of ECs to brief periods of low FSS, examining its impact on endothelial traction-a measure of cellular tension that plays a crucial role in how endothelial cells respond to mechanical stimuli. By integrating traction force microscopy (TFM) with a custom-built flow chamber, we analyzed how human umbilical vein endothelial cells (HUVECs) adjust their traction in response to shifts from low to high shear stress. We discovered that initial exposure to low FSS prompts a marked increase in traction force, which continues to rise over 10 hours before slowly decreasing. In contrast, immediate exposure to high FSS causes a quick spike in traction followed by a swift reduction, revealing distinct patterns of traction behavior under different shear conditions. Importantly, the direction of traction forces and the resulting cellular alignment under these conditions indicate that the initial shear experience dictates long-term endothelial behavior. Our findings shed light on the critical influence of short-lived low-shear stress experiences in shaping endothelial function, indicating that early exposure to low FSS results in enduring changes in endothelial contractility and alignment, with significant consequences for vascular health and the development of cardiovascular diseases.
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Affiliation(s)
- Mohanish K. Chandurkar
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931
- Health Research Institute, Michigan Technological University, Houghton, MI 49931
| | - Nikhil Mittal
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931
- Health Research Institute, Michigan Technological University, Houghton, MI 49931
| | - Shaina P. Royer-Weeden
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931
- Health Research Institute, Michigan Technological University, Houghton, MI 49931
| | - Steven D. Lehmann
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931
| | - Yeonwoo Rho
- Department of Mathematical Sciences, Michigan Technological University, Houghton, MI 49931
| | - Sangyoon J. Han
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931
- Health Research Institute, Michigan Technological University, Houghton, MI 49931
- Department of Mechanical Engineering and Engineering Mechanics, Michigan Technological University, Houghton, MI 49931
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4
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Barazzuol L, Coppes RP, van Luijk P. Prevention and treatment of radiotherapy-induced side effects. Mol Oncol 2020; 14:1538-1554. [PMID: 32521079 PMCID: PMC7332214 DOI: 10.1002/1878-0261.12750] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 05/29/2020] [Accepted: 06/02/2020] [Indexed: 01/10/2023] Open
Abstract
Radiotherapy remains a mainstay of cancer treatment, being used in roughly 50% of patients. The precision with which the radiation dose can be delivered is rapidly improving. This precision allows the more accurate targeting of radiation dose to the tumor and reduces the amount of surrounding normal tissue exposed. Although this often reduces the unwanted side effects of radiotherapy, we still need to further improve patients' quality of life and to escalate radiation doses to tumors when necessary. High-precision radiotherapy forces one to choose which organ or functional organ substructures should be spared. To be able to make such choices, we urgently need to better understand the molecular and physiological mechanisms of normal tissue responses to radiotherapy. Currently, oversimplified approaches using constraints on mean doses, and irradiated volumes of normal tissues are used to plan treatments with minimized risk of radiation side effects. In this review, we discuss the responses of three different normal tissues to radiotherapy: the salivary glands, cardiopulmonary system, and brain. We show that although they may share very similar local cellular processes, they respond very differently through organ-specific, nonlocal mechanisms. We also discuss how a better knowledge of these mechanisms can be used to treat or to prevent the effects of radiotherapy on normal tissue and to optimize radiotherapy delivery.
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Affiliation(s)
- Lara Barazzuol
- Department of Biomedical Sciences of Cells and SystemsUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
- Department of Radiation OncologyUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | - Rob P. Coppes
- Department of Biomedical Sciences of Cells and SystemsUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
- Department of Radiation OncologyUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | - Peter van Luijk
- Department of Biomedical Sciences of Cells and SystemsUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
- Department of Radiation OncologyUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
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5
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Jafarihaghighi F, Ardjmand M, Mirzadeh A, Hassani MS, Parizi SS. Current challenges and future trends in manufacturing small diameter artificial vascular grafts in bioreactors. Cell Tissue Bank 2020; 21:377-403. [PMID: 32415569 DOI: 10.1007/s10561-020-09837-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 05/09/2020] [Indexed: 01/17/2023]
Abstract
Cardiovascular diseases are a leading cause of death. Vascular surgery is mainly used to solve this problem. However, the generation of a functional and suitable substitute for small diameter (< 6 mm) displacement is challengeable. Moreover, synthetic prostheses, made of polyethylene terephthalate and extended polytetrafluoroethylene show have shown insufficient performance. Therefore, the challenges dominating the use of autografts have prevented their efficient use. Tissue engineering is highlighted in regenerative medicine perhaps in aiming to address the issue of end-stage organ failure. While organs and complex tissues require the vascular supply to support the graft survival and render the bioartificial organ role, vascular tissue engineering has shown to be a hopeful method for cell implantation by the production of tissues in vitro. Bioreactors are a salient point in vascular tissue engineering due to the capability for reproducible and controlled variations showing a new horizon in blood vessel substitution. This review strives to display the overview of current concepts in the development of small-diameter by using bioreactors. In this work, we show a critical look at different factors for developing small-diameter and give suggestions for future studies.
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Affiliation(s)
- Farid Jafarihaghighi
- Department of Chemical Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Mehdi Ardjmand
- Department of Chemical Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran.
| | - Abolfazl Mirzadeh
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3052, Australia
| | - Mohammad Salar Hassani
- Department of Chemical Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Shahriar Salemi Parizi
- Department of Chemical Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
- Young Researchers and Elite Club, South Tehran Branch, Islamic Azad University, Tehran, Iran
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6
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Marinval N, Morenc M, Labour M, Samotus A, Mzyk A, Ollivier V, Maire M, Jesse K, Bassand K, Niemiec-Cyganek A, Haddad O, Jacob M, Chaubet F, Charnaux N, Wilczek P, Hlawaty H. Fucoidan/VEGF-based surface modification of decellularized pulmonary heart valve improves the antithrombotic and re-endothelialization potential of bioprostheses. Biomaterials 2018; 172:14-29. [DOI: 10.1016/j.biomaterials.2018.01.054] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 01/29/2018] [Accepted: 01/29/2018] [Indexed: 12/02/2022]
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Jaganathan SK, M MP, Fauzi Ismail A, A M, N G. Production and hemocompatibility assessment of novel electrospun polyurethane nanofibers loaded with dietary virgin coconut oil for vascular graft applications. J BIOACT COMPAT POL 2017. [DOI: 10.1177/0883911517720815] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
To develop biodegradable polymer scaffolds suitable for vascular tissue engineering applications, the bioengineering community has invested an extensive effort. The most common cause for the failure of vascular graft scaffolds is thrombosis. In this work, the scaffold based on polyurethane and virgin coconut oil was produced by electrospinning process for vascular tissue engineering applications with improved antithrombogenicity. The diameter of this electrospun polyurethane/virgin coconut oil composite was found to be reduced in the range of 886 ± 207 nm compared to pristine polyurethane which was in the range of 969 ± 217 nm. The Fourier transform infrared spectroscopy analysis revealed the interaction between polyurethane and virgin coconut oil as indicated by phase shifting of CH bond along with the formation of hydrogen bond. The contact angle measurement of fabricated composites was found to be increased owing to hydrophobic nature and also exhibited enhanced thermal stability as noted in thermogravimetric analysis. The atomic force microscopy analysis insinuated the increased surface roughness of the composite in comparison with the pure polyurethane. Developed scaffold resulted in delayed blood clotting as revealed by activated partial thromboplastin time and partial thromboplastin time assay. The hemolytic index of fabricated composites was found to be low indicating the enhanced safety of red blood cells. Hence, the newly developed nanofibrous composite scaffold could open the door for a suitable alternative for vascular graft applications.
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Affiliation(s)
- Saravana Kumar Jaganathan
- Department for Management of Science and Technology Development, Ton Duc Thang University, Ho Chi Minh City, Vietnam
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
- IJN-UTM Cardiovascular Engineering Center, Department of Clinical Sciences, Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, Skudai 81300, Johor, Malaysia
| | - Mohan Prasath M
- Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, Skudai 81300, Johor, Malaysia
| | - Ahmad Fauzi Ismail
- Advanced Membrane Technology Research Centre (AMTEC), Universiti Teknologi Malaysia, Skudai 81310, Johor, Malaysia
| | - Manikandan A
- Department of Chemistry, Bharath Institute of Higher Education and Research, Bharath University Chennai 600073, Tamil Nadu, India
| | - Gomathi N
- Department of Chemistry, Indian Institute of Space Science and Technology, Thiruvananthapuram 695547, India
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8
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Park JH, Jang J, Lee JS, Cho DW. Current advances in three-dimensional tissue/organ printing. Tissue Eng Regen Med 2016; 13:612-621. [PMID: 30603443 PMCID: PMC6170865 DOI: 10.1007/s13770-016-8111-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 12/14/2015] [Accepted: 12/22/2015] [Indexed: 01/04/2023] Open
Abstract
Three-dimensional (3D) tissue/organ printing is a major aspect of recent innovation in the field of tissue engineering and regenerative medicine. 3D tissue/organ printing aims to create 3D living tissue/organ analogues, and have evolved along with advances in 3D printing techniques. A diverse range of computer-aided 3D printing techniques have been applied to dispose living cells together with biomaterials and supporting biochemical factors within pre-designed 3D tissue/organ analogues. Recent developments in printable biomaterials, such as decellularized extracellular matrix bio-inks have enabled improvements in the functionality of the resulting 3D tissue/organ analogues. Here, we provide an overview of the 3D printing techniques and biomaterials that have been used, including the development of 3D tissue/organ analogues. In addition, in vitro models are described, and future perspectives in 3D tissue/organ printing are identified.
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Affiliation(s)
- Jeong Hun Park
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Jinah Jang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Jung-Seob Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Dong-Woo Cho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Korea
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, 37673 Korea
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9
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White SJ, Newby AC, Johnson TW. Endothelial erosion of plaques as a substrate for coronary thrombosis. Thromb Haemost 2016; 115:509-19. [PMID: 26791872 DOI: 10.1160/th15-09-0765] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 12/09/2015] [Indexed: 01/28/2023]
Abstract
Myocardial infarction is a prevalent, life-threatening consequence of athero-thrombosis. Post-mortem histology and intravascular imaging in live patients have shown that approximately one third of myocardial infarctions are caused by a thrombus overlying an intact, non-ruptured atherosclerotic plaque. Histology identifies erosion of luminal endothelial cells from smooth muscle and proteoglycan-rich, thick fibrous cap atheromas as the underlying pathology. Unlike plaque ruptures, endothelial erosions tend to occur on thick-capped atherosclerotic plaques and may or may not be associated with inflammation. Smoking and female gender are strong risk factors for erosion. Multiple mechanisms may contribute to endothelial erosion, including endothelial dysfunction, TLR signalling, leukocyte activation and modification of sub-endothelial matrix by endothelial or smooth muscle cells, which may trigger loss of adhesion to the extracellular matrix or endothelial apoptosis. Diagnosis of endothelial erosion by intravascular imaging, especially high resolution optical coherence tomography, may influence treatment strategies, offering prognostic value and utility as an endpoint in trials of agents designed to preserve an intact coronary endothelium.
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Affiliation(s)
- Stephen J White
- Dr Stephen White, University of Bristol, School of Clinical Sciences, Level 7, Queens Building, Bristol Royal Infirmary, Bristol, BS2 8HW, UK, Tel.: +44 117 3423190, E-mail:
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Andreou I, Antoniadis AP, Shishido K, Papafaklis MI, Koskinas KC, Chatzizisis YS, Coskun AU, Edelman ER, Feldman CL, Stone PH. How do we prevent the vulnerable atherosclerotic plaque from rupturing? Insights from in vivo assessments of plaque, vascular remodeling, and local endothelial shear stress. J Cardiovasc Pharmacol Ther 2014; 20:261-75. [PMID: 25336461 DOI: 10.1177/1074248414555005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 08/14/2014] [Indexed: 01/13/2023]
Abstract
Coronary atherosclerosis progresses both as slow, gradual enlargement of focal plaque and also as a more dynamic process with periodic abrupt changes in plaque geometry, size, and morphology. Systemic vasculoprotective therapies such as statins, angiotensin-converting enzyme inhibitors, and antiplatelet agents are the cornerstone of prevention of plaque rupture and new adverse clinical outcomes, but such systemic therapies are insufficient to prevent the majority of new cardiac events. Invasive imaging methods have been able to identify both the anatomic features of high-risk plaque and the ongoing pathobiological stimuli responsible for progressive plaque inflammation and instability and may provide sufficient information to formulate preventive local mechanical strategies (eg, preemptive percutaneous coronary interventions) to avert cardiac events. Local endothelial shear stress (ESS) triggers vascular phenomena that synergistically exacerbate atherosclerosis toward an unstable phenotype. Specifically, low ESS augments lipid uptake and catabolism, induces plaque inflammation and oxidation, downregulates the production, upregulates the degradation of extracellular matrix, and increases cellular apoptosis ultimately leading to thin-cap fibroatheromas and/or endothelial erosions. Increases in blood thrombogenicity that result from either high or low ESS also contribute to plaque destabilization. An understanding of the actively evolving vascular phenomena, as well as the development of in vivo imaging methodologies to identify the presence and severity of the different processes, may enable early identification of a coronary plaque destined to acquire a high-risk state and allow for highly selective, focal preventive interventions to avert the adverse natural history of that particular plaque. In this review, we focus on the role of ESS in the pathobiologic processes responsible for plaque destabilization, leading either to accelerated plaque growth or to acute coronary events, and emphasize the potential to utilize in vivo risk stratification of individual coronary plaques to optimize prevention strategies to preclude new cardiac events.
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Affiliation(s)
- Ioannis Andreou
- The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Antonios P Antoniadis
- The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Koki Shishido
- The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Michail I Papafaklis
- The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Konstantinos C Koskinas
- The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Yiannis S Chatzizisis
- The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Ahmet U Coskun
- The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Elazer R Edelman
- The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Charles L Feldman
- The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Peter H Stone
- The Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
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11
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Bartnikowski M, Klein TJ, Melchels FP, Woodruff MA. Effects of scaffold architecture on mechanical characteristics and osteoblast response to static and perfusion bioreactor cultures. Biotechnol Bioeng 2014; 111:1440-51. [DOI: 10.1002/bit.25200] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 01/13/2014] [Accepted: 01/21/2014] [Indexed: 01/04/2023]
Affiliation(s)
- Michal Bartnikowski
- Institute of Health and Biomedical Innovation; Queensland University of Technology; 60 Musk Avenue Kelvin Grove Queensland 4059 Australia
| | - Travis J. Klein
- Institute of Health and Biomedical Innovation; Queensland University of Technology; 60 Musk Avenue Kelvin Grove Queensland 4059 Australia
| | - Ferry P.W. Melchels
- Institute of Health and Biomedical Innovation; Queensland University of Technology; 60 Musk Avenue Kelvin Grove Queensland 4059 Australia
- Department of Orthopedics; University Medical Center Utrecht; Utrecht Holland
| | - Maria A. Woodruff
- Institute of Health and Biomedical Innovation; Queensland University of Technology; 60 Musk Avenue Kelvin Grove Queensland 4059 Australia
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12
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Malda J, Visser J, Melchels FP, Jüngst T, Hennink WE, Dhert WJA, Groll J, Hutmacher DW. 25th anniversary article: Engineering hydrogels for biofabrication. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:5011-28. [PMID: 24038336 DOI: 10.1002/adma.201302042] [Citation(s) in RCA: 1066] [Impact Index Per Article: 96.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 06/19/2013] [Indexed: 05/19/2023]
Abstract
With advances in tissue engineering, the possibility of regenerating injured tissue or failing organs has become a realistic prospect for the first time in medical history. Tissue engineering - the combination of bioactive materials with cells to generate engineered constructs that functionally replace lost and/or damaged tissue - is a major strategy to achieve this goal. One facet of tissue engineering is biofabrication, where three-dimensional tissue-like structures composed of biomaterials and cells in a single manufacturing procedure are generated. Cell-laden hydrogels are commonly used in biofabrication and are termed "bioinks". Hydrogels are particularly attractive for biofabrication as they recapitulate several features of the natural extracellular matrix and allow cell encapsulation in a highly hydrated mechanically supportive three-dimensional environment. Additionally, they allow for efficient and homogeneous cell seeding, can provide biologically-relevant chemical and physical signals, and can be formed in various shapes and biomechanical characteristics. However, despite the progress made in modifying hydrogels for enhanced bioactivation, cell survival and tissue formation, little attention has so far been paid to optimize hydrogels for the physico-chemical demands of the biofabrication process. The resulting lack of hydrogel bioinks have been identified as one major hurdle for a more rapid progress of the field. In this review we summarize and focus on the deposition process, the parameters and demands of hydrogels in biofabrication, with special attention to robotic dispensing as an approach that generates constructs of clinically relevant dimensions. We aim to highlight this current lack of effectual hydrogels within biofabrication and initiate new ideas and developments in the design and tailoring of hydrogels. The successful development of a "printable" hydrogel that supports cell adhesion, migration, and differentiation will significantly advance this exciting and promising approach for tissue engineering.
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Affiliation(s)
- Jos Malda
- Department of Orthopaedics, University Medical Center Utrecht, P.O. Box 85500, 3508, GA Utrecht, The Netherlands; Institute of Health and Biomedical Innovation, Queensland University of TechnologyKelvin Grove Urban Village, Brisbane, QLD 4059, Australia; Department of Equine Sciences, Faculty of Veterinary Sciences, Utrecht University, Yalelaan 112, 3584 CM, Utrecht, The Netherlands
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13
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Application of computational fluid dynamics in tissue engineering. J Biosci Bioeng 2012; 114:123-32. [DOI: 10.1016/j.jbiosc.2012.03.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 03/07/2012] [Accepted: 03/21/2012] [Indexed: 01/14/2023]
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Rennier K, Ji JY. Shear stress regulates expression of death-associated protein kinase in suppressing TNFα-induced endothelial apoptosis. J Cell Physiol 2012; 227:2398-411. [PMID: 21826654 DOI: 10.1002/jcp.22975] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Death associated protein kinase (DAPK) is a positive regulator in tumor necrosis factor α (TNFα)-induced apoptotic pathway, and DAPK expression is lost in cancer cells. In the vasculature, misdirected apoptosis in endothelial cells leads to pathological conditions such as inflammation and physiological shear stress is protective against apoptosis. Using bovine aortic endothelial cells, we found that DAPK expression increased, while the auto-inhibitory phosphorylation of serine 308 decreased with shear stress at 12 dynes/cm(2) for 6 h. Quantitative RT-PCR revealed a corresponding increase in DAPK mRNA [P < 0.01]. We found that after 18-h TNFα induction, shearing cells for another 6 h significantly reduced apoptosis based on TUNEL staining [P < 0.05], although cell necrosis was not affected. Under the same conditions, we observed significantly decreased overall DAPK, as well as phospho-serine 308 DAPK [P < 0.05] compared to TNFα treatment alone. Caspase-3 and -7 activities downstream of DAPK were also attenuated. Shearing cells alone resulted in enhanced apoptosis, likely due to increased DAPK activity. Our findings were further supported by DAPK siRNA, which yielded contrary results. We present conclusive evidence for the first time that shear stress of up to 6 h up-regulates DAPK expression and activation. However, in the presence of apoptotic stimuli such as TNFα, shear stress caused decrease in DAPK activity. In fact, long-term shear stress of 24 h significantly reduced overall DAPK expression. Our findings strongly support a novel role for DAPK in mediating effects of shear stress in suppressing cytokine-activated apoptosis.
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Affiliation(s)
- Keith Rennier
- Department of Biomedical Engineering, Purdue School of Engineering and Technology, Indiana University Purdue University Indianapolis, Indianapolis, Indiana 46202, USA
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Melchels FPW, Tonnarelli B, Olivares AL, Martin I, Lacroix D, Feijen J, Wendt DJ, Grijpma DW. The influence of the scaffold design on the distribution of adhering cells after perfusion cell seeding. Biomaterials 2011; 32:2878-84. [PMID: 21288567 DOI: 10.1016/j.biomaterials.2011.01.023] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 01/08/2011] [Indexed: 10/18/2022]
Abstract
In natural tissues, the extracellular matrix composition, cell density and physiological properties are often non-homogeneous. Here we describe a model system, in which the distribution of cells throughout tissue engineering scaffolds after perfusion seeding can be influenced by the pore architecture of the scaffold. Two scaffold types, both with gyroid pore architectures, were designed and built by stereolithography: one with isotropic pore size (412 ± 13 μm) and porosity (62 ± 1%), and another with a gradient in pore size (250-500 μm) and porosity (35%-85%). Computational fluid flow modelling showed a uniform distribution of flow velocities and wall shear rates (15-24 s(-1)) for the isotropic architecture, and a gradient in the distribution of flow velocities and wall shear rates (12-38 s(-1)) for the other architecture. The distribution of cells throughout perfusion-seeded scaffolds was visualised by confocal microscopy. The highest densities of cells correlated with regions of the scaffolds where the pores were larger, and the fluid velocities and wall shear rates were the highest. Under the applied perfusion conditions, cell deposition is mainly determined by local wall shear stress, which, in turn, is strongly influenced by the architecture of the pore network of the scaffold.
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Affiliation(s)
- Ferry P W Melchels
- MIRA Institute for Biomedical Technology and Technical Medicine, Department of Polymer Chemistry and Biomaterials, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
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Platelets prevent acute liver damage after extended hepatectomy in pigs. JOURNAL OF HEPATO-BILIARY-PANCREATIC SCIENCES 2010; 17:855-64. [PMID: 20734209 DOI: 10.1007/s00534-010-0276-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Accepted: 02/25/2010] [Indexed: 02/07/2023]
Abstract
BACKGROUND/PURPOSE Platelets develop tissue repair and promote liver regeneration. We investigated whether platelets prevented acute liver damage after extended hepatectomy in pigs. METHODS Thrombocytosis was induced by the following two methods; afterwards 80% hepatectomy was performed in pigs. In the first method, the pigs received administration of thrombopoietin [TPO (+) group], and they were compared with a control group [TPO (-) group]. In the second method, the pigs received a splenectomy [Sp (+) group], and theywere compared with another control group [Sp (-) group]. Platelet counts, biochemical examination of blood, and histopathological findings of the residual liver were examined. RESULTS Serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and total bilirubin (T-Bil) levels were significantly decreased in the thrombocytotic groups compared with the control groups in the early period after hepatectomy. In the histopathological findings, hemorrhagic necrosis with a bile plug was observed in the control groups, but this phenomenon was not observed in the thrombocytotic groups. On transmission electron microscopy, the sinusoidal endothelial lining was destroyed and detached into the sinusoidal space with enlargement of Disse's spaces in the thrombocytotic groups, but these findings were not observed in the control groups. CONCLUSION An increased number of platelets prevents acute liver damage after extended hepatectomy.
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Lawrence BJ, Devarapalli M, Madihally SV. Flow dynamics in bioreactors containing tissue engineering scaffolds. Biotechnol Bioeng 2009; 102:935-47. [PMID: 18949759 DOI: 10.1002/bit.22106] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Bioreactors are widely used in tissue engineering as a way to distribute nutrients within porous materials and provide physical stimulus required by many tissues. However, the fluid dynamics within the large porous structure are not well understood. In this study, we explored the effect of reactor geometry by using rectangular and circular reactors with three different inlet and outlet patterns. Geometries were simulated with and without the porous structure using the computational fluid dynamics software Comsol Multiphysics 3.4 and/or ANSYS CFX 11 respectively. Residence time distribution analysis using a step change of a tracer within the reactor revealed non-ideal fluid distribution characteristics within the reactors. The Brinkman equation was used to model the permeability characteristics with in the chitosan porous structure. Pore size was varied from 10 to 200 microm and the number of pores per unit area was varied from 15 to 1,500 pores/mm(2). Effect of cellular growth and tissue remodeling on flow distribution was also assessed by changing the pore size (85-10 microm) while keeping the number of pores per unit area constant. These results showed significant increase in pressure with reduction in pore size, which could limit the fluid flow and nutrient transport. However, measured pressure drop was marginally higher than the simulation results. Maximum shear stress was similar in both reactors and ranged approximately 0.2-0.3 dynes/cm(2). The simulations were validated experimentally using both a rectangular and circular bioreactor, constructed in-house. Porous structures for the experiments were formed using 0.5% chitosan solution freeze-dried at -80 degrees C, and the pressure drop across the reactor was monitored.
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Affiliation(s)
- Benjamin J Lawrence
- School of Chemical Engineering, Oklahoma State University, 423 Engineering North, Stillwater, Oklahoma 74078, USA
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Tillman BW, Yazdani SK, Lee SJ, Geary RL, Atala A, Yoo JJ. The in vivo stability of electrospun polycaprolactone-collagen scaffolds in vascular reconstruction. Biomaterials 2008; 30:583-8. [PMID: 18990437 DOI: 10.1016/j.biomaterials.2008.10.006] [Citation(s) in RCA: 293] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Accepted: 10/03/2008] [Indexed: 11/28/2022]
Abstract
To avoid complications of prosthetic vascular grafts, engineered vascular constructs have been investigated as an alternative for vascular reconstruction. The scaffolds for vascular tissue engineering remain a cornerstone of these efforts and yet many currently available options are limited by issues of inconsistency, poor adherence of vascular cells, or inadequate biomechanical properties. In this study, we investigated whether PCL/collagen scaffolds could support cell growth and withstand physiologic conditions while maintaining patency in a rabbit aortoiliac bypass model. Our results indicate that electrospun scaffolds support adherence and growth of vascular cells under physiologic conditions and that endothelialized grafts resisted adherence of platelets when exposed to blood. When implanted in vivo, these scaffolds were able to retain their structural integrity over 1 month of implantation as demonstrated by serial ultrasonography. Further, at retrieval, these scaffolds continued to maintain biomechanical strength that was comparable to native artery. This study suggests that electrospun scaffolds combined with vascular cells may become an alternative to prosthetic vascular grafts for vascular reconstruction.
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Affiliation(s)
- Bryan W Tillman
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA.
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