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Yi B, Xu Q, Liu W. An overview of substrate stiffness guided cellular response and its applications in tissue regeneration. Bioact Mater 2022; 15:82-102. [PMID: 35386347 PMCID: PMC8940767 DOI: 10.1016/j.bioactmat.2021.12.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/03/2021] [Accepted: 12/03/2021] [Indexed: 02/06/2023] Open
Abstract
Cell-matrix interactions play a critical role in tissue repair and regeneration. With gradual uncovering of substrate mechanical characteristics that can affect cell-matrix interactions, much progress has been made to unravel substrate stiffness-mediated cellular response as well as its underlying mechanisms. Yet, as a part of cell-matrix interaction biology, this field remains in its infancy, and the detailed molecular mechanisms are still elusive regarding scaffold-modulated tissue regeneration. This review provides an overview of recent progress in the area of the substrate stiffness-mediated cellular responses, including 1) the physical determination of substrate stiffness on cell fate and tissue development; 2) the current exploited approaches to manipulate the stiffness of scaffolds; 3) the progress of recent researches to reveal the role of substrate stiffness in cellular responses in some representative tissue-engineered regeneration varying from stiff tissue to soft tissue. This article aims to provide an up-to-date overview of cell mechanobiology research in substrate stiffness mediated cellular response and tissue regeneration with insightful information to facilitate interdisciplinary knowledge transfer and enable the establishment of prognostic markers for the design of suitable biomaterials. Substrate stiffness physically determines cell fate and tissue development. Rational design of scaffolds requires the understanding of cell-matrix interactions. Substrate stiffness depends on scaffold molecular-constituent-structure interaction. Substrate stiffness-mediated cellular responses vary in different tissues.
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2
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Increased Risk of Aortic Dissection with Perlecan Deficiency. Int J Mol Sci 2021; 23:ijms23010315. [PMID: 35008739 PMCID: PMC8745340 DOI: 10.3390/ijms23010315] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 12/24/2021] [Accepted: 12/25/2021] [Indexed: 12/22/2022] Open
Abstract
Perlecan (HSPG2), a basement membrane-type heparan sulfate proteoglycan, has been implicated in the development of aortic tissue. However, its role in the development and maintenance of the aortic wall remains unknown. Perlecan-deficient mice (Hspg2−/−-Tg: Perl KO) have been found to show a high frequency (15–35%) of aortic dissection (AD). Herein, an analysis of the aortic wall of Perl KO mice revealed that perlecan deficiency caused thinner and partially torn elastic lamina. Compared to the control aortic tissue, perlecan-deficient aortic tissue showed a significant decrease in desmosine content and an increase in soluble tropoelastin levels, implying the presence of immature elastic fibers in Perl KO mice. Furthermore, the reduced expression of the smooth muscle cell contractile proteins actin and myosin in perlecan-deficient aortic tissue may explain the risk of AD. This study showed that a deficiency in perlecan, which is localized along the elastic lamina and at the interface between elastin and fibrillin-1, increased the risk of AD, largely due to the immaturity of extracellular matrix in the aortic tissue. Overall, we proposed a new model of AD that considers the deficiency of extracellular molecule perlecan as a risk factor.
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Youn J, Han H, Park SM, Kim DS. Arterial Internal Elastic Lamina-Inspired Membrane for Providing Biochemical and Structural Cues in Developing Artery-on-a-Chip. ACS Macro Lett 2021; 10:1398-1403. [PMID: 35549015 DOI: 10.1021/acsmacrolett.1c00551] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In vitro artery models constructed on a membrane-based microfluidic chip, called an artery-on-a-chip, have been spotlighted as a powerful platform for studying arterial physiology. However, due to the use of a flat and porous membrane that cannot mimic the in vivo internal elastic lamina (IEL), the physiological similarity in the phenotypes and the arrangements of the endothelial cells (ECs) and aortic smooth muscle cells (AoSMCs) has been limited in the previously developed artery-on-a-chips. Herein, we developed an innovative membrane mimicking the structures of IEL by utilizing electrospun aligned silk fibroin/polycaprolactone nanofiber membranes. An arterial IEL-mimicking (AIM) membrane was about 5 μm thick and composed of orthogonally aligned nanofibers with a diameter of around 400 nm, which were highly comparable to the IEL. Such structural similarity was found to induce the ECs and SMCs to be elongated and orthogonally aligned as in the in vivo artery. In particular, the SMCs cultured on the AIM membrane maintained a healthy state showing increased αSMA mRNA expression, which was easily lost on the conventional membrane. We constructed an AIM membrane-integrated artery-on-a-chip having an orthogonal arrangement of ECs and SMCs, which was desirable but difficult to be realized with the previous artery-on-a-chip.
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Affiliation(s)
- Jaeseung Youn
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, South Korea
| | - Hyeonseok Han
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, South Korea
| | - Sang Min Park
- School of Mechanical Engineering, Pusan National University, 2, Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan 46241, South Korea
| | - Dong Sung Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, South Korea.,Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, South Korea.,Institute for Convergence Research and Education in Advanced Technology, Yonsei University, Seoul 03722, South Korea
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Wertheimer S, Sharabi M, Shelah O, Lesman A, Haj-Ali R. Bio-composites reinforced with unique coral collagen fibers: Towards biomimetic-based small diameter vascular grafts. J Mech Behav Biomed Mater 2021; 119:104526. [PMID: 33894525 DOI: 10.1016/j.jmbbm.2021.104526] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 03/15/2021] [Accepted: 04/09/2021] [Indexed: 01/01/2023]
Abstract
Cardiovascular Diseases (CVDs) are the leading cause of death worldwide. Approximately 31% of all global deaths are caused by CVDs, of which 42% are attributable to coronary artery disease (CAD). CAD is characterized by a narrowing of arteries that restricts the normal blood flow. Over time, surgical intervention is required in severe cases of occlusions and includes implantation of autologous vessels. Today synthetic grafts are used successfully as replacements for blood vessels with a diameter larger than 6 mm. However, they often fail as small-diameter blood vessel replacements. This study introduces a new biocomposite material system consisting of unique and long (cm-scale) collagen fibers derived from soft corals embedded within an alginate hydrogel matrix. The new biocomposite layers were used to fabricate grafts, towards developing a new class of tissue-engineered small-diameter blood vessels. These constructs consisted of both circumferentially and longitudinally oriented collagen fibers. The mechanical properties of the grafts were investigated via a new experimental setup constructed in our lab for this purpose, which applied internal pressure levels of 0-300 mmHg. Similar to native coronary arteries, the biocomposite tubes demonstrated a compliance of 4.88 ± 0.99%/100 mmHg for a physiologic pressure range of 80-120 mmHg. Furthermore, a numerical finite element simulation model is proposed to generate the overall mechanical response of the construct. It is composed of axial and circumferential fibers embedded within the continuum alginate elements. Good prediction is demonstrated when compared with the measured pressure-strain response. Moreover, we examined biocompatibility and cell growth on the collagen fibers. Fibroblast cells proliferated during the experiment that lasted for 32 days and showed aligned configuration with the collagen fiber orientation. The novelty of this study is manifested in the use of naturally derived coral-based long collagen fibers for the development of a new class of tissue-engineered grafts. The proposed novel biocomposite graft demonstrated both mechanical and biological compatibility and can be further developed for small-diameter blood-vessel replacement.
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Affiliation(s)
- Shir Wertheimer
- The Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Mirit Sharabi
- The Faculty of Engineering, Ariel University, Ariel, 407000, Israel
| | - Ortal Shelah
- The Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Ayelet Lesman
- The Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Rami Haj-Ali
- The Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, 69978, Israel.
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5
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Shelah O, Wertheimer S, Haj-Ali R, Lesman A. Coral-Derived Collagen Fibers for Engineering Aligned Tissues. Tissue Eng Part A 2020; 27:187-200. [PMID: 32524890 DOI: 10.1089/ten.tea.2020.0116] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
There is a growing need for biomaterial scaffolds that support engineering of soft tissue substitutes featuring structure and mechanical properties similar to those of the native tissue. This work introduces a new biomaterial system that is based on centimeter-long collagen fibers extracted from Sarcophyton soft corals, wrapped around frames to create aligned fiber arrays. The collagen arrays displayed hyperelastic and viscoelastic mechanical properties that resembled those of collagenous-rich tissues. Cytotoxicity tests demonstrated that the collagen arrays were nontoxic to fibroblast cells. In addition, fibroblast cells seeded on the collagen arrays demonstrated spreading and increased growth for up to 40 days, and their orientation followed that of the aligned fibers. The possibility to combine the collagen cellular arrays with poly(ethylene glycol) diacrylate (PEG-DA) hydrogel, to create integrated biocomposites, was also demonstrated. This study showed that coral collagen fibers in combination with a hydrogel can support biological tissue-like growth, with predefined orientation over a long period of time in culture. As such, it is an attractive scaffold for the construction of various engineered tissues to match their native oriented morphology.
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Affiliation(s)
- Ortal Shelah
- School of Mechanical Engineering, The Fleischman Faculty of Engineering, Tel-Aviv University, Israel
| | - Shir Wertheimer
- School of Mechanical Engineering, The Fleischman Faculty of Engineering, Tel-Aviv University, Israel
| | - Rami Haj-Ali
- School of Mechanical Engineering, The Fleischman Faculty of Engineering, Tel-Aviv University, Israel
| | - Ayelet Lesman
- School of Mechanical Engineering, The Fleischman Faculty of Engineering, Tel-Aviv University, Israel
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Ding Y, Johnson R, Sharma S, Ding X, Bryant SJ, Tan W. Tethering transforming growth factor β1 to soft hydrogels guides vascular smooth muscle commitment from human mesenchymal stem cells. Acta Biomater 2020; 105:68-77. [PMID: 31982589 DOI: 10.1016/j.actbio.2020.01.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 01/10/2020] [Accepted: 01/21/2020] [Indexed: 12/15/2022]
Abstract
Mesenchymal stem cells (MSCs) hold great promise for vascular smooth muscle regeneration. However, most studies have mainly relied on extended supplementation of sophisticated biochemical regimen to drive MSC differentiation towards vascular smooth muscle cells (vSMCs). Herein we demonstrate a concomitant method that exploits the advantages of biomimetic matrix stiffness and tethered transforming growth factor β1 (TGF-β1) to guide vSMC commitment from human MSCs. Our designed poly(ethylene glycol) hydrogels, presenting a biomimetic stiffness and tethered TGF-β1, provide an instructive environment to potently upregulate smooth muscle marker expression in vitro and in vivo. Importantly, it significantly enhances the functional contractility of vSMCs derived from MSCs within 3 days. Interestingly, compared to non-tethered one, tethered TGF-β1 enhanced the potency of vSMC commitment on hydrogels. We provide compelling evidence that combining stiffness and tethered TGF-β1 on poly(ethylene glycol) hydrogels can be a promising approach to drastically enhance maturation and function of vSMCs from stem cell differentiation in vitro and in vivo. STATEMENT OF SIGNIFICANCE: A fast, reliable and safe regeneration of vascular smooth muscle cells (vSMCs) from stem cell differentiation is promising for vascular tissue engineering and regenerative medicine applications, but remains challenging. Herein, a photo-click hydrogel platform is devised to recapitulate the stiffness of vascular tissue and appropriate presentation of transforming growth factor β1 (TGF-β1) to guide vSMC commitment from mesenchymal stem cells (MSCs). We demonstrate that such concomitant method drastically enhanced regeneration of mature, functional vSMCs from MSCs in vitro and in vivo within only a 3-days span. This work is not only of fundamental scientific importance, revealing how physiochemical factors and the manner of their presentation direct stem cell differentiation, but also attacks the long-standing difficulty in regenerating highly functional vSMCs within a short period.
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Yan S, Napiwocki B, Xu Y, Zhang J, Zhang X, Wang X, Crone WC, Li Q, Turng LS. Wavy small-diameter vascular graft made of eggshell membrane and thermoplastic polyurethane. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 107:110311. [PMID: 31761197 PMCID: PMC6905500 DOI: 10.1016/j.msec.2019.110311] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 09/17/2019] [Accepted: 10/12/2019] [Indexed: 12/17/2022]
Abstract
In this study, a small-diameter, double-layered eggshell membrane/thermoplastic polyurethane (ESM/TPU) vascular graft with a wavy structure was developed. The avian eggshell membrane, a fibrous structure similar to the extracellular matrix (ECM), has the potential to yield rapid endothelialization in vitro. The dopamine and heparin modification of the ESM surface not only promoted human umbilical vein endothelial cell (HUVEC) proliferation via cytocompatibility assessment, but also improved its anticoagulation properties as verified in platelet adhesion tests. The biomimetic mechanical properties of the vascular graft were provided by the elastic TPU fibers via electrospinning using a wavy cross-section rotating collector. The advantage of combining these two materials is to make use of the bioactivity of ESM as the internal membrane and the tunable mechanical properties of TPU as the external layer. The circumferentially wavy structure of the vascular graft produced a toe region in the non-linear section of the stress-strain curve similar to that of natural blood vessels. The ESM/TPU graft's circumferential ultimate strength was 2.57 MPa, its strain was 339% mm/mm, and its toe region was found to be around 20% mm/mm. Cyclical tension tests showed that the vascular graft could maintain good mechanical properties and showed no structural damage under repeated extension tests.
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Affiliation(s)
- Shujie Yan
- School of Mechanics and Engineering Science, Zhengzhou University, Zhengzhou, China; National Center for International Research of Micro-Nano Molding Technology Zhengzhou University, Zhengzhou, China; Polymer Engineering Center, Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI, USA; Wisconsin Institute for Discovery University of Wisconsin-Madison, Madison, WI, USA
| | - Brett Napiwocki
- Wisconsin Institute for Discovery University of Wisconsin-Madison, Madison, WI, USA
| | - Yiyang Xu
- School of Mechanics and Engineering Science, Zhengzhou University, Zhengzhou, China; National Center for International Research of Micro-Nano Molding Technology Zhengzhou University, Zhengzhou, China; Polymer Engineering Center, Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI, USA; Wisconsin Institute for Discovery University of Wisconsin-Madison, Madison, WI, USA
| | - Jue Zhang
- Morgridge Institute for Research, Madison, WI, USA
| | - Xiang Zhang
- School of Mechanics and Engineering Science, Zhengzhou University, Zhengzhou, China; National Center for International Research of Micro-Nano Molding Technology Zhengzhou University, Zhengzhou, China
| | - Xiaofeng Wang
- School of Mechanics and Engineering Science, Zhengzhou University, Zhengzhou, China; National Center for International Research of Micro-Nano Molding Technology Zhengzhou University, Zhengzhou, China
| | - Wendy C Crone
- Wisconsin Institute for Discovery University of Wisconsin-Madison, Madison, WI, USA
| | - Qian Li
- School of Mechanics and Engineering Science, Zhengzhou University, Zhengzhou, China; National Center for International Research of Micro-Nano Molding Technology Zhengzhou University, Zhengzhou, China.
| | - Lih-Sheng Turng
- Polymer Engineering Center, Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI, USA; Wisconsin Institute for Discovery University of Wisconsin-Madison, Madison, WI, USA.
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Mi HY, Jiang Y, Jing X, Enriquez E, Li H, Li Q, Turng LS. Fabrication of triple-layered vascular grafts composed of silk fibers, polyacrylamide hydrogel, and polyurethane nanofibers with biomimetic mechanical properties. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 98:241-249. [DOI: 10.1016/j.msec.2018.12.126] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/09/2018] [Accepted: 12/28/2018] [Indexed: 12/21/2022]
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9
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Mi H, Jing X, Li Z, Lin Y, Thomson JA, Turng L. Fabrication and modification of wavy multicomponent vascular grafts with biomimetic mechanical properties, antithrombogenicity, and enhanced endothelial cell affinity. J Biomed Mater Res B Appl Biomater 2019; 107:2397-2408. [DOI: 10.1002/jbm.b.34333] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 12/31/2018] [Accepted: 01/05/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Hao‐Yang Mi
- Wisconsin Institute for DiscoveryUniversity of Wisconsin–Madison Madison Wisconsin 53715 USA
- Department of Mechanical EngineeringUniversity of Wisconsin–Madison Madison Wisconsin, 53706 USA
| | - Xin Jing
- Wisconsin Institute for DiscoveryUniversity of Wisconsin–Madison Madison Wisconsin 53715 USA
- Department of Mechanical EngineeringUniversity of Wisconsin–Madison Madison Wisconsin, 53706 USA
- School of Packaging and Materials EngineeringHunan University of Technology Zhuzhou, 412007 China
| | - Zhu‐Tong Li
- Wisconsin Institute for DiscoveryUniversity of Wisconsin–Madison Madison Wisconsin 53715 USA
- Department of Mechanical EngineeringUniversity of Wisconsin–Madison Madison Wisconsin, 53706 USA
| | - Yu‐Jyun Lin
- Wisconsin Institute for DiscoveryUniversity of Wisconsin–Madison Madison Wisconsin 53715 USA
| | - James A. Thomson
- Morgridge Institute for ResearchUniversity of Wisconsin–Madison Madison Wisconsin, 53715 USA
| | - Lih‐Sheng Turng
- Wisconsin Institute for DiscoveryUniversity of Wisconsin–Madison Madison Wisconsin 53715 USA
- Department of Mechanical EngineeringUniversity of Wisconsin–Madison Madison Wisconsin, 53706 USA
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Nguyen TU, Shojaee M, Bashur CA, Kishore V. Electrochemical fabrication of a biomimetic elastin-containing bi-layered scaffold for vascular tissue engineering. Biofabrication 2018; 11:015007. [PMID: 30411718 DOI: 10.1088/1758-5090/aaeab0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Biomimetic tissue-engineered vascular grafts (TEVGs) have immense potential to replace diseased small-diameter arteries (<4 mm) for the treatment of cardiovascular diseases. However, biomimetic approaches developed thus far only partially recapitulate the physicochemical properties of the native vessel. While it is feasible to fabricate scaffolds that are compositionally similar to native vessels (collagen and insoluble elastic matrix) using freeze-drying, these scaffolds do not mimic the aligned topography of collagen and elastic fibers found in native vessels. Extrusion-based scaffolds exhibit anisotropic collagen orientation but these scaffolds are compositionally dissimilar (cannot incorporate insoluble elastic matrix). In this study, an electrochemical fabrication technique was employed to develop a biomimetic elastin-containing bi-layered collagen scaffold which is compositionally and structurally similar to native vessels and the effect of insoluble elastin incorporation on scaffold mechanics and smooth muscle cell (SMC) response was investigated. Further, the functionality of human umbilical vein endothelial cells (HUVECs) on the scaffold lumen surface was assessed via immunofluorescence. Results showed that incorporation of insoluble elastin maintained the overall collagen alignment within electrochemically aligned collagen (ELAC) fibers and this underlying aligned topography can direct cellular orientation. Ring test results showed that circumferential orientation of ELAC fibers significantly improved scaffold mechanics. Real-time PCR revealed that the expression of α-smooth muscle actin (Acta2) and myosin heavy chain (MyhII) was significantly higher on elastin containing scaffolds suggesting that the presence of insoluble elastin can promote contractility in SMCs. Further, mechanical properties of the scaffolds significantly improved post-culture indicating the presence of a mature cell-synthesized and remodeled matrix. Finally, HUVECs expressed functional markers on collagen lumen scaffolds. In conclusion, electrochemical fabrication is a viable method for the generation of a functional biomimetic TEVG with the potential to be used in bypass surgery.
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Affiliation(s)
- Thuy-Uyen Nguyen
- Department of Chemical Engineering, Florida Institute of Technology, Melbourne, FL 32901, United States of America
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Yu E, Mi HY, Zhang J, Thomson JA, Turng LS. Development of biomimetic thermoplastic polyurethane/fibroin small-diameter vascular grafts via a novel electrospinning approach. J Biomed Mater Res A 2018; 106:985-996. [PMID: 29143442 PMCID: PMC5826852 DOI: 10.1002/jbm.a.36297] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 10/28/2017] [Accepted: 11/10/2017] [Indexed: 12/18/2022]
Abstract
A new electrospinning approach for fabricating vascular grafts with a layered, circumferentially aligned, and micro-wavy fibrous structure similar to natural elastic tissues has been developed. The customized electrospinning collector was able to generate wavy fibers using the dynamic "jump rope" collecting process, which also solved the sample removal problem for mandrel-type collectors. In this study, natural silk fibroin and synthetic thermoplastic polyurethane (TPU) were combined at different weight ratios to produce hybrid small-diameter vascular grafts. The purpose of combining these two materials was to leverage the bioactivity and tunable mechanical properties of these natural and synthetic materials. Results showed that the electrospun fiber morphology was highly influenced by the material compositions and solvents employed. All of the TPU/fibroin hybrid grafts had mechanical properties comparable to natural blood vessels. The circumferentially aligned and wavy biomimetic configuration provided the grafts with a sufficient toe region and the capacity for long-term usage under repeated dilatation and contraction. Cell culture tests with human endothelial cells (EC) also revealed high cell viability and good biocompatibility for these grafts. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 985-996, 2018.
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Affiliation(s)
- Emily Yu
- Department of Mechanical Engineering, University of Wisconsin–Madison, WI, USA, 53706
- Wisconsin Institute for Discovery, University of Wisconsin–Madison, WI, USA, 53715
| | - Hao-Yang Mi
- Department of Mechanical Engineering, University of Wisconsin–Madison, WI, USA, 53706
- Wisconsin Institute for Discovery, University of Wisconsin–Madison, WI, USA, 53715
- Department of Industrial Equipment and Control Engineering, South China University of Technology, Guangzhou, China
| | - Jue Zhang
- Morgridge Institute for Research, WI, USA, 53715
| | | | - Lih-Sheng Turng
- Department of Mechanical Engineering, University of Wisconsin–Madison, WI, USA, 53706
- Wisconsin Institute for Discovery, University of Wisconsin–Madison, WI, USA, 53715
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Eoh JH, Shen N, Burke JA, Hinderer S, Xia Z, Schenke-Layland K, Gerecht S. Enhanced elastin synthesis and maturation in human vascular smooth muscle tissue derived from induced-pluripotent stem cells. Acta Biomater 2017; 52:49-59. [PMID: 28163239 DOI: 10.1016/j.actbio.2017.01.083] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 12/29/2016] [Accepted: 01/30/2017] [Indexed: 10/20/2022]
Abstract
Obtaining vascular smooth muscle tissue with mature, functional elastic fibers is a key obstacle in tissue-engineered blood vessels. Poor elastin secretion and organization leads to a loss of specialization in contractile smooth muscle cells, resulting in over proliferation and graft failure. In this study, human induced-pluripotent stem cells (hiPSCs) were differentiated into early smooth muscle cells, seeded onto a hybrid poly(ethylene glycol) dimethacrylate/poly (l-lactide) (PEGdma-PLA) scaffold and cultured in a bioreactor while exposed to pulsatile flow, towards maturation into contractile smooth muscle tissue. We evaluated the effects of pulsatile flow on cellular organization as well as elastin expression and assembly in the engineered tissue compared to a static control through immunohistochemistry, gene expression and functionality assays. We show that culturing under pulsatile flow resulted in organized and functional hiPSC derived smooth muscle tissue. Immunohistochemistry analysis revealed hiPSC-smooth muscle tissue with robust, well-organized cells and elastic fibers and the supporting microfibril proteins necessary for elastic fiber assembly. Through qRT-PCR analysis, we found significantly increased expression of elastin, fibronectin, and collagen I, indicating the synthesis of necessary extracellular matrix components. Functionality assays revealed that hiPSC-smooth muscle tissue cultured in the bioreactor had an increased calcium signaling and contraction in response to a cholinergic agonist, significantly higher mature elastin content and improved mechanical properties in comparison to the static control. The findings presented here detail an effective approach to engineering elastic human vascular smooth muscle tissue with the functionality necessary for tissue engineering and regenerative medicine applications. STATEMENT OF SIGNIFICANCE Obtaining robust, mature elastic fibers is a key obstacle in tissue-engineered blood vessels. Human induced-pluripotent stem cells have become of interest due to their ability to supplement tissue engineered scaffolds. Their ability to differentiate into cells of vascular lineages with defined phenotypes serves as a potential solution to a major cause of graft failure in which phenotypic shifts in smooth muscle cells lead to over proliferation and occlusion of the graft. Herein, we have differentiated human induced-pluripotent stem cells in a pulsatile flow bioreactor, resulting in vascular smooth muscle tissue with robust elastic fibers and enhanced functionality. This study highlights an effective approach to engineering elastic functional vascular smooth muscle tissue for tissue engineering and regenerative medicine applications.
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Lou CW, Lu PC, Hu JJ, Lin JH. Effects of yarn types and fabric types on the compliance and bursting strength of vascular grafts. J Mech Behav Biomed Mater 2016; 59:474-483. [DOI: 10.1016/j.jmbbm.2016.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Revised: 03/01/2016] [Accepted: 03/03/2016] [Indexed: 01/14/2023]
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14
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Nguyen TU, Bashur CA, Kishore V. Impact of elastin incorporation into electrochemically aligned collagen fibers on mechanical properties and smooth muscle cell phenotype. Biomed Mater 2016; 11:025008. [PMID: 26987364 DOI: 10.1088/1748-6041/11/2/025008] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Application of tissue-engineered vascular grafts (TEVGs) for the replacement of small-diameter arteries is limited due to thrombosis and intimal hyperplasia. Previous studies have attempted to address the limitations of TEVGs by developing scaffolds that mimic the composition (collagen and elastin) of native arteries to better match the mechanical properties of the graft with the native tissue. However, most existing scaffolds do not recapitulate the aligned topography of the collagen fibers found in native vessels. In the current study, based on the principles of isoelectric focusing, two different types of elastin (soluble and insoluble) were incorporated into highly oriented electrochemically aligned collagen (ELAC) fibers and the effect of elastin incorporation on the mechanical properties of the ELAC fibers and smooth muscle cell (SMC) phenotype was investigated. The results indicate that elastin incorporation significantly decreased the modulus of ELAC fibers to converge upon that of native vessels. Further, a significant increase in yield strain and decrease in Young's modulus was observed on all fibers post SMC culture compared with before the culture. Real-time polymerase chain reaction results showed a significant increase in the expression of α-smooth muscle actin and calponin on ELAC fibers with insoluble elastin, suggesting that incorporation of insoluble elastin induces a contractile phenotype in SMCs after two weeks of culture on ELAC fibers. Immunofluorescence results showed that calponin expression increased with time on all fibers. In conclusion, insoluble elastin incorporated ELAC fibers have the potential to be used for the development of functional TEVGs for the repair and replacement of small-diameter arteries.
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Affiliation(s)
- Thuy-Uyen Nguyen
- Department of Chemical Engineering, Florida Institute of Technology, Melbourne, FL 32901, USA
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15
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Hinderer S, Brauchle E, Schenke-Layland K. Generation and Assessment of Functional Biomaterial Scaffolds for Applications in Cardiovascular Tissue Engineering and Regenerative Medicine. Adv Healthc Mater 2015; 4:2326-41. [PMID: 25778713 PMCID: PMC4745029 DOI: 10.1002/adhm.201400762] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/11/2015] [Indexed: 12/27/2022]
Abstract
Current clinically applicable tissue and organ replacement therapies are limited in the field of cardiovascular regenerative medicine. The available options do not regenerate damaged tissues and organs, and, in the majority of the cases, show insufficient restoration of tissue function. To date, anticoagulant drug-free heart valve replacements or growing valves for pediatric patients, hemocompatible and thrombus-free vascular substitutes that are smaller than 6 mm, and stem cell-recruiting delivery systems that induce myocardial regeneration are still only visions of researchers and medical professionals worldwide and far from being the standard of clinical treatment. The design of functional off-the-shelf biomaterials as well as automatable and up-scalable biomaterial processing methods are the focus of current research endeavors and of great interest for fields of tissue engineering and regenerative medicine. Here, various approaches that aim to overcome the current limitations are reviewed, focusing on biomaterials design and generation methods for myocardium, heart valves, and blood vessels. Furthermore, novel contact- and marker-free biomaterial and extracellular matrix assessment methods are highlighted.
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Affiliation(s)
- Svenja Hinderer
- Department of Cell and Tissue Engineering, Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), Nobelstrasse 12, Stuttgart, 70569, Germany
- Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen, Silcherstr. 7/1, Tübingen, 72076, Germany
| | - Eva Brauchle
- Department of Cell and Tissue Engineering, Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), Nobelstrasse 12, Stuttgart, 70569, Germany
- Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen, Silcherstr. 7/1, Tübingen, 72076, Germany
- Institute of Interfacial Process Engineering and Plasma Technology (IGVP), University of Stuttgart, Nobelstrasse 12, Stuttgart, 70569, Germany
| | - Katja Schenke-Layland
- Department of Cell and Tissue Engineering, Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), Nobelstrasse 12, Stuttgart, 70569, Germany
- Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen, Silcherstr. 7/1, Tübingen, 72076, Germany
- Department of Medicine/Cardiology, Cardiovascular Research Laboratories, David Geffen School of Medicine at the, University of California Los Angeles (UCLA), Los Angeles, CA, USA
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16
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Lomas A, Ryan C, Sorushanova A, Shologu N, Sideri A, Tsioli V, Fthenakis G, Tzora A, Skoufos I, Quinlan L, O'Laighin G, Mullen A, Kelly J, Kearns S, Biggs M, Pandit A, Zeugolis D. The past, present and future in scaffold-based tendon treatments. Adv Drug Deliv Rev 2015; 84:257-77. [PMID: 25499820 DOI: 10.1016/j.addr.2014.11.022] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 11/08/2014] [Accepted: 11/12/2014] [Indexed: 02/07/2023]
Abstract
Tendon injuries represent a significant clinical burden on healthcare systems worldwide. As the human population ages and the life expectancy increases, tendon injuries will become more prevalent, especially among young individuals with long life ahead of them. Advancements in engineering, chemistry and biology have made available an array of three-dimensional scaffold-based intervention strategies, natural or synthetic in origin. Further, functionalisation strategies, based on biophysical, biochemical and biological cues, offer control over cellular functions; localisation and sustained release of therapeutics/biologics; and the ability to positively interact with the host to promote repair and regeneration. Herein, we critically discuss current therapies and emerging technologies that aim to transform tendon treatments in the years to come.
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17
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Bashur CA, Ramamurthi A. Composition of intraperitoneally implanted electrospun conduits modulates cellular elastic matrix generation. Acta Biomater 2014; 10:163-72. [PMID: 24016842 DOI: 10.1016/j.actbio.2013.08.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 08/07/2013] [Accepted: 08/29/2013] [Indexed: 12/28/2022]
Abstract
Improving elastic matrix generation is critical to developing functional tissue engineered vascular grafts. Therefore, this study pursued a strategy to grow autologous tissue in vivo by recruiting potentially more elastogenic cells to conduits implanted within the peritoneal cavity. The goal was to determine the impacts of electrospun conduit composition and hyaluronan oligomer (HA-o) modification on the recruitment of peritoneal cells, and their phenotype and ability to synthesize elastic matrix. These responses were assessed as a function of conduit intra-peritoneal implantation time. This study showed that the blending of collagen with poly(ε-caprolactone) (PCL) promotes a faster wound healing response, as assessed by trends in expression of macrophage and smooth muscle cell (SMC) contractile markers and in matrix deposition, compared to the more chronic response for PCL alone. This result, along with the increase in elastic matrix production, demonstrates the benefits of incorporating as little as 25% w/w collagen into the conduit. In addition, PCR analysis demonstrated the challenges in differentiating between a myofibroblast and an SMC using traditional phenotypic markers. Finally, the impact of the tethered HA-o is limited within the inflammatory environment, unlike the significant response found previously in vitro. In conclusion, these results demonstrate the importance of both careful control of implanted scaffold composition and the development of appropriate delivery methods for HA-o.
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18
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Vassalli M, Sbrana F, Laurita A, Papi M, Bloise N, Visai L, Bochicchio B. Biological and structural characterization of a naturally inspired material engineered from elastin as a candidate for tissue engineering applications. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:15898-15906. [PMID: 24328291 DOI: 10.1021/la403311x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The adoption of a biomimetic approach in the design and fabrication of innovative materials for biomedical applications is encountering a growing interest. In particular, new molecules are being engineered on the basis of proteins present in the extracellular matrix, such as fibronectin, collagen, or elastin. Following this approach scientists expect to be able not only to obtain materials with tailored mechanical properties but also to elicit specific biological responses inherited by the mimicked tissue. In the present work, a novel peptide, engineered starting from the sequence encoded by exon 28 of human tropoelastin, was characterized from a chemical, physical, and biological point of view. The obtained molecule was observed to aggregate at high temperatures, forming a material able to induce a biological effect similar to what elastin does in the physiological context. This material seems to be a good candidate to play a relevant role in future biomedical applications with special reference to vascular surgery.
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Affiliation(s)
- Massimo Vassalli
- Institute of Biophysics, National Research Council, Genova, Italy
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19
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Lee P, Bax DV, Bilek MMM, Weiss AS. A novel cell adhesion region in tropoelastin mediates attachment to integrin αVβ5. J Biol Chem 2013; 289:1467-77. [PMID: 24293364 DOI: 10.1074/jbc.m113.518381] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Tropoelastin protein monomers assemble to form elastin. Cellular integrin αVβ3 binds RKRK at the C-terminal tail of tropoelastin. We probed cell interactions with tropoelastin by deleting the RKRK sequence to identify other cell-binding interactions within tropoelastin. We found a novel human dermal fibroblast attachment and spreading site on tropoelastin that is located centrally in the molecule. Inhibition studies demonstrated that this cell adhesion was not mediated by either elastin-binding protein or glycosaminoglycans. Cell interactions were divalent cation-dependent, indicating integrin dependence. Function-blocking monoclonal antibodies revealed that αV integrin(s) and integrin αVβ5 specifically were critical for cell adhesion to this part of tropoelastin. These data reveal a common αV integrin-binding theme for tropoelastin: αVβ3 at the C terminus and αVβ5 at the central region of tropoelastin. Each αV region contributes to fibroblast attachment and spreading, but they differ in their effects on cytoskeletal assembly.
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Affiliation(s)
- Pearl Lee
- From the School of Molecular Bioscience
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20
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Cellularized microcarriers as adhesive building blocks for fabrication of tubular tissue constructs. Ann Biomed Eng 2013; 42:1470-81. [PMID: 23943070 DOI: 10.1007/s10439-013-0883-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 07/29/2013] [Indexed: 10/26/2022]
Abstract
To meet demands of vascular reconstruction, there is a need for prosthetic alternatives to natural blood vessels. Here we explored a new conduit fabrication approach. Macroporous, gelatin microcarriers laden with human umbilical vein endothelial cells and aortic smooth muscle cells were dispensed into tubular agarose molds and found to adhere to form living tubular tissues. The ability of cellularized microcarriers to adhere to one another involved cellular and extracellular matrix bridging that included the formation of epithelium-like cell layers lining the lumenal and ablumenal surfaces of the constructs and the deposition of collagen and elastin fibers. The tubular tissues behaved as elastic solids, with a uniaxial mechanical response that is qualitatively similar to that of native vascular tissues and consistent with their elastin and collagen composition. Linearized measures of the mechanical response of the fabricated tubular tissues at both low and high strains were observed to increase with duration of static culture, with no significant loss of stiffness following decellularization. The findings highlight the utility of cellularized macroporous gelatin microcarriers as self-adhering building blocks for the fabrication of living tubular structures.
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21
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Zhang P, Huang A, Morales-Ruiz M, Starcher BC, Huang Y, Sessa WC, Niklason LE, Giordano FJ. Engineered zinc-finger proteins can compensate genetic haploinsufficiency by transcriptional activation of the wild-type allele: application to Willams-Beuren syndrome and supravalvular aortic stenosis. Hum Gene Ther 2013; 23:1186-99. [PMID: 22891920 DOI: 10.1089/hum.2011.201] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Williams-Beuren syndrome (WBS) and supravalvular aortic stenosis (SVAS) are genetic syndromes marked by the propensity to develop severe vascular stenoses. Vascular lesions in both syndromes are caused by haploinsufficiency of the elastin gene. We used these distinct genetic syndromes as models to evaluate the feasibility of using engineered zinc-finger protein transcription factors (ZFPs) to achieve compensatory expression of haploinsufficient genes by inducing augmented expression from the remaining wild-type allele. For complex genes with multiple splice variants, this approach could have distinct advantages over cDNA-based gene replacement strategies. Targeting the elastin gene, we show that transcriptional activation by engineered ZFPs can induce compensatory expression from the wild-type allele in the setting of classic WBS and SVAS genetic mutations, increase elastin expression in wild-type cells, induce expression of the major elastin splice variants, and recapitulate their natural stoichiometry. Further, we establish that transcriptional activation of the mutant allele in SVAS does not overcome nonsense-mediated decay, and thus ZFP-mediated transcriptional activation is not likely to induce production of a mutant protein, a crucial consideration. Finally, we show in bioengineered blood vessels that ZFP-mediated induction of elastin expression is capable of stimulating functional elastogenesis. Haploinsufficiency is a common mechanism of genetic disease. These findings have significant implications for WBS and SVAS, and establish that haploinsufficiency can be overcome by targeted transcriptional activation without inducing protein expression from the mutant allele.
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Affiliation(s)
- Pei Zhang
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT 06520, USA
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22
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Bashur CA, Eagleton MJ, Ramamurthi A. Impact of electrospun conduit fiber diameter and enclosing pouch pore size on vascular constructs grown within rat peritoneal cavities. Tissue Eng Part A 2012; 19:809-23. [PMID: 23075322 DOI: 10.1089/ten.tea.2012.0309] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The generation of vascular grafts by recruiting autologous cells within the peritoneal cavity has shown promise. However, the microenvironment affects cell differentiation and elastic matrix production. Therefore, this study determined the impact of systematic changes in the average fiber diameter of electrospun poly(ɛ-caprolactone) conduits, and the pore size of pouches used to enclose the conduits, on recruited cells. After 2 weeks in the peritoneal cavity, fibrous capsules formed containing macrophages, α-smooth muscle actin (α-SMA)(+) and SM22α(+) myofibroblastic or smooth muscle like-cells, and what appeared to be mesothelial cells on the outer surfaces. These cells infiltrated and deposited matrix (e.g., collagen, hyaluoronan, and limited elastin) within conduit walls. Constructs enclosed within the largest pore pouches exhibited significantly better tissue generation responses (e.g., better cell infiltration, elongation, and matrix deposition). Additionally, the healing response was impacted by the conduit average fiber diameter, and consequently, the effective pore diameter, with the largest diameter fibers promoting the most positive healing response (e.g., greater total cellularity, extracellular matrix deposition, and α-SMA(+) cells). Six weeks post-intra-aortal grafting, constructs were occluded, but significant remodeling also occurred in the arterial microenvironment. Overall, these results demonstrate the importance of microenvironmental cues on recruited peritoneal cells and the necessity of developing strategies to further improve elastic matrix synthesis.
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Affiliation(s)
- Chris A Bashur
- Department of Biomedical Engineering, Cleveland Clinic, Cleveland, OH 44195, USA
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23
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Hayes AJ, Smith SM, Melrose J. Comparative immunolocalisation of fibrillin-1 and perlecan in the human foetal, and HS-deficient hspg2 exon 3 null mutant mouse intervertebral disc. Histochem Cell Biol 2012; 139:1-11. [PMID: 23104139 DOI: 10.1007/s00418-012-1041-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2012] [Indexed: 12/20/2022]
Abstract
The aim of this study was to examine the comparative localisations of fibrillin-1 and perlecan in the foetal human, wild-type C57BL/6 and HS-deficient hspg2Δ³⁻/Δ³⁻ exon 3 null mouse intervertebral disc (IVD) using fluorescent laser scanning confocal microscopy. Fibrillin-1 fibrils were prominent components of the outer posterior and anterior annulus fibrosus (AF) of the foetal human IVD. Finer fibrillin-1 fibrils were evident in the inner AF where they displayed an arcade-type arrangement in the developing lamellae. Relatively short but distinct fibrillin-1 fibrils were evident in the central region of the IVD and presumptive cartilaginous endplate and defined the margins of the nuclear sheath in the developing nucleus pulposus (NP). Fibrillin-1 was also demonstrated in the AF of C57BL/6 wild-type mice but to a far lesser extent in the HS-deficient hspg2Δ³⁻/Δ³⁻ exon 3 null mouse. This suggested that the HS chains of perlecan may have contributed to fibrillin-1 assembly or its deposition in the IVD. The cell-matrix interconnections provided by the fibrillin fibrils visualised in this study may facilitate communication between disc cells and their local biomechanical microenvironment in mechanosensory processes which regulate tissue homeostasis. The ability of fibrillin-1 to sequester TGF-β a well-known anabolic growth factor in the IVD also suggests potential roles in disc development and/or remodelling.
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Affiliation(s)
- Anthony J Hayes
- Confocal Microscopy Unit, Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3US, Wales, UK
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24
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Sivaraman B, Bashur CA, Ramamurthi A. Advances in biomimetic regeneration of elastic matrix structures. Drug Deliv Transl Res 2012; 2:323-50. [PMID: 23355960 PMCID: PMC3551595 DOI: 10.1007/s13346-012-0070-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Elastin is a vital component of the extracellular matrix, providing soft connective tissues with the property of elastic recoil following deformation and regulating the cellular response via biomechanical transduction to maintain tissue homeostasis. The limited ability of most adult cells to synthesize elastin precursors and assemble them into mature crosslinked structures has hindered the development of functional tissue-engineered constructs that exhibit the structure and biomechanics of normal native elastic tissues in the body. In diseased tissues, the chronic overexpression of proteolytic enzymes can cause significant matrix degradation, to further limit the accumulation and quality (e.g., fiber formation) of newly deposited elastic matrix. This review provides an overview of the role and importance of elastin and elastic matrix in soft tissues, the challenges to elastic matrix generation in vitro and to regenerative elastic matrix repair in vivo, current biomolecular strategies to enhance elastin deposition and matrix assembly, and the need to concurrently inhibit proteolytic matrix disruption for improving the quantity and quality of elastogenesis. The review further presents biomaterial-based options using scaffolds and nanocarriers for spatio-temporal control over the presentation and release of these biomolecules, to enable biomimetic assembly of clinically relevant native elastic matrix-like superstructures. Finally, this review provides an overview of recent advances and prospects for the application of these strategies to regenerating tissue-type specific elastic matrix structures and superstructures.
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Affiliation(s)
- Balakrishnan Sivaraman
- Department of Biomedical Engineering, The Cleveland Clinic, 9500 Euclid Avenue, ND 20, Cleveland, OH 44195, USA
| | - Chris A. Bashur
- Department of Biomedical Engineering, The Cleveland Clinic, 9500 Euclid Avenue, ND 20, Cleveland, OH 44195, USA
| | - Anand Ramamurthi
- Department of Biomedical Engineering, The Cleveland Clinic, 9500 Euclid Avenue, ND 20, Cleveland, OH 44195, USA
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25
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Wang F, Li Z, Guan J. Fabrication of mesenchymal stem cells-integrated vascular constructs mimicking multiple properties of the native blood vessels. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 24:769-83. [PMID: 23594067 DOI: 10.1080/09205063.2012.712029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mesenchymal stem cells (MSCs)-populated small diameter (6 mm) vascular constructs were fabricated. The constructs mimicked the native vessels in multiple levels, i.e. having similar structure and morphology to that of the extracellular matrix in the native blood vessels; recapitulating mechanical properties such as compliance and burst pressure of the native blood vessels; simulating the highly cellularized nature of the native blood vessels; and having an antithrombogenic lumen. The constructs were fabricated by simultaneously assembling poly(ester carbonate urethane) urea nanofibers and MSCs in an electrical field. The nanofibers had a diameter similar to that of the collagen and elastin fibers in the native blood vessels. MSCs were distributed evenly in the constructs. The constructs were highly cellularized when the cell loading density was exceeded 6 million/ml. The vascular constructs were strong and flexible with breaking strains of 144-202%, tensile strengths of 0.80-1.29 MPa, compliances of 13.23-21.96 × 10(-4 )mmHg(-1), stiffness indexes of 7.3-9.8, and burst pressures greater than 1700 mmHg. These mechanical properties were similar to those of the native blood vessels. In vitro platelet deposition experiments showed that platelet adhesion was remarkably decreased in the MSCs-populated constructs compared to that in the construct without MSCs. An increase in MSC density in the constructs further decreased platelet adhesion. When cultured in a spinner flask, MSCs maintained their mitochondria viability and cell number during a two-week culture period, as confirmed by MTT and dsDNA assays. These vascular constructs may hold the potential to regenerate functional small diameter vessels for cardiovascular tissue repair.
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Affiliation(s)
- Feng Wang
- Department of Materials Science and Engineering, The Ohio State University, 2041 College Road, Columbus, OH 43210, USA
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26
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Consonni SR, Werneck CC, Sobreira DR, Kühne F, Moraes SG, Alvares LE, Joazeiro PP. Elastic fiber assembly in the adult mouse pubic symphysis during pregnancy and postpartum. Biol Reprod 2012; 86:151, 1-10. [PMID: 22238283 DOI: 10.1095/biolreprod.111.095653] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Impairment of pelvic organ support has been described in mice with genetic modifications of the proteins involved in elastogenesis, such as lysyl oxidase-like 1 (LOXL1) and fibulin 5. During pregnancy, elastic fiber-enriched pelvic tissues are modified to allow safe delivery. In addition, the mouse pubic symphysis is remodeled in a hormone-controlled process that entails the modification of the fibrocartilage into an interpubic ligament (IpL) and the relaxation of this ligament. After first parturition, recovery occurs to ensure pelvic tissue homeostasis. Because ligaments are the main supports of the pelvic organs, this study aimed to evaluate elastogenesis in the IpL during mouse pregnancy and postpartum. Accordingly, virgin, pregnant, and postpartum C57BL/6 mice were studied using light, confocal, and transmission electron microscopy as well as Western blots and real-time PCR. Female mice exhibited the separation of the pubic bones and the formation, relaxation, and postpartum recovery of the IpL. By the time the IpL was formed, the elastic fibers had increased in profile length and diameter, and they consisted of small conglomerates of amorphous material distributed among the bundles of microfibrils. Our analyses also indicated that elastin/tropoelastin, fibrillin 1, LOXL1/Loxl1, and fibulin 5 were spatially and temporally regulated, suggesting that these molecules may contribute to the synthesis of new elastic fibers during IpL development. Overall, this work revealed that adult elastogenesis may be important to assure the elasticity of the pelvic girdle during preparation for parturition and postpartum recovery. This finding may contribute to our understanding of pathological processes involving elastogenesis in the reproductive tract.
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Affiliation(s)
- Sílvio Roberto Consonni
- Department of Histology and Embryology, State University of Campinas (Unicamp), Campinas, Brazil
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27
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Thurstan SA, Gibbs NK, Langton AK, Griffiths CE, Watson RE, Sherratt MJ. Chemical consequences of cutaneous photoageing. Chem Cent J 2012; 6:34. [PMID: 22534143 PMCID: PMC3410765 DOI: 10.1186/1752-153x-6-34] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Accepted: 04/25/2012] [Indexed: 12/28/2022] Open
Abstract
Human skin, in common with other organs, ages as a consequence of the passage of time, but in areas exposed to solar ultraviolet radiation, the effects of this intrinsic ageing process are exacerbated. In particular, both the severity and speed of onset of age-related changes, such as wrinkle formation and loss of elasticity, are enhanced in photoaged (also termed extrinsically aged) as compared with aged, photoprotected, skin. The anatomy of skin is characterised by two major layers: an outer, avascular, yet highly cellular and dynamic epidermis and an underlying vascularised, comparatively static and cell-poor, dermis. The structural consequences of photoageing are mainly evident in the extracellular matrix-rich but cell-poor dermis where key extracellular matrix proteins are particularly susceptible to photodamage. Most investigations to date have concentrated on the cell as both a target for and mediator of, ultraviolet radiation-induced photoageing. As the main effectors of dermal remodelling produced by cells (extracellular proteases) generally have low substrate specificity, we recently suggested that the differential susceptibility of key extracellular matrix proteins to the processes of photoageing may be due to direct, as opposed to cell-mediated, photodamage. In this review, we discuss the experimental evidence for ultraviolet radiation (and related reactive oxygen species)-mediated differential degradation of normally long lived dermal proteins including the fibrillar collagens, elastic fibre components, glycoproteins and proteoglycans. Whilst these components exhibit highly diverse primary and hence macro- and supra-molecular structures, we present evidence that amino acid composition alone may be a useful predictor of age-related protein degradation in both photoexposed and, as a consequence of differential oxidation sensitivity, photoprotected, tissues.
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Affiliation(s)
- Sarah A Thurstan
- Developmental Biomedicine Research Groups, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK.
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28
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Patel D, Vandromme SE, Reid ME, Taite LJ. Synergistic Activity of αvβ3 Integrins and the Elastin Binding Protein Enhance Cell-Matrix Interactions on Bioactive Hydrogel Surfaces. Biomacromolecules 2012; 13:1420-8. [DOI: 10.1021/bm300144y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Dhaval Patel
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
| | - Susan E. Vandromme
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
| | - Michael E. Reid
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
| | - Lakeshia J. Taite
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
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29
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Srokowski EM, Blit PH, McClung WG, Brash JL, Santerre JP, Woodhouse KA. Platelet Adhesion and Fibrinogen Accretion on a Family of Elastin-Like Polypeptides. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 22:41-57. [DOI: 10.1163/092050609x12578498935594] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- E. M. Srokowski
- a Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - P. H. Blit
- b Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - W. G. McClung
- c Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada; Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - J. L. Brash
- d Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada; Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada; School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada
| | - J. P. Santerre
- e Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Department of Biomaterials, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - K. A. Woodhouse
- f Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Department of Chemical Engineering, Queen's University, Kingston, ON, Canada
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30
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Bashur CA, Venkataraman L, Ramamurthi A. Tissue engineering and regenerative strategies to replicate biocomplexity of vascular elastic matrix assembly. TISSUE ENGINEERING PART B-REVIEWS 2012; 18:203-17. [PMID: 22224468 DOI: 10.1089/ten.teb.2011.0521] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cardiovascular tissues exhibit architecturally complex extracellular matrices, of which the elastic matrix forms a major component. The elastic matrix critically maintains native structural configurations of vascular tissues, determines their ability to recoil after stretch, and regulates cell signaling pathways involved in morphogenesis, injury response, and inflammation via biomechanical transduction. The ability to tissue engineer vascular replacements that incorporate elastic matrix superstructures unique to cardiac and vascular tissues is thus important to maintaining vascular homeostasis. However, the vascular elastic matrix is particularly difficult to tissue engineer due to the inherently poor ability of adult vascular cells to synthesize elastin precursors and organize them into mature structures in a manner that replicates the biocomplexity of elastic matrix assembly during development. This review discusses current tissue engineering materials (e.g., growth factors and scaffolds) and methods (e.g., dynamic stretch and contact guidance) used to promote cellular synthesis and assembly of elastic matrix superstructures, and the limitations of these approaches when applied to smooth muscle cells, the primary elastin-generating cell type in vascular tissues. The potential application of these methods for in situ regeneration of disrupted elastic matrix at sites of proteolytic vascular disease (e.g., abdominal aortic aneurysms) is also discussed. Finally, the review describes the potential utility of alternative cell types to elastic tissue engineering and regenerative matrix repair. Future progress in the field is contingent on developing a thorough understanding of developmental elastogenesis and then mimicking the spatiotemporal changes in the cellular microenvironment that occur during that phase. This will enable us to tissue engineer clinically applicable elastic vascular tissue replacements and to develop elastogenic therapies to restore homeostasis in de-elasticized vessels.
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Affiliation(s)
- Chris A Bashur
- Department of Biomedical Engineering, Cleveland Clinic, Cleveland, Ohio, USA
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Hayes AJ, Lord MS, Smith SM, Smith MM, Whitelock JM, Weiss AS, Melrose J. Colocalization in vivo and association in vitro of perlecan and elastin. Histochem Cell Biol 2011; 136:437-54. [PMID: 21874555 DOI: 10.1007/s00418-011-0854-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2011] [Indexed: 12/30/2022]
Abstract
We have colocalized elastin and fibrillin-1 with perlecan in extracellular matrix of tensional and weight-bearing connective tissues. Elastin and fibrillin-1 were identified as prominent components of paraspinal blood vessels, and posterior longitudinal ligament in the human fetal spine and outer annulus fibrosus of the fetal intervertebral disc. We also colocalized perlecan with a synovial elastic basal lamina, where the attached synovial cells were observed to produce perlecan. Elastin, fibrillin-1 and perlecan were co-localized in the intima and media of small blood vessels in the synovium and in human fetal paraspinal blood vessels. Elastic fibers were observed at the insertion point of the anterior cruciate ligament to bone in the ovine stifle joint where they colocalized with perlecan. Elastin has not previously been reported to be spatially associated with perlecan in these tissues. Interactions between the tropoelastin and perlecan heparan sulfate chains were demonstrated using quartz crystal microbalance with dissipation solid phase binding studies. Electrostatic interactions through the heparan sulfate chains of perlecan and core protein mediated the interactions with tropoelastin, and were both important in the coacervation of tropoelastin and deposition of elastin onto perlecan immobilized on the chip surface. This may help us to understand the interactions which are expected to occur in vivo between the tropoelastin and perlecan to facilitate the deposition of elastin and formation of elastic microfibrils in situ and would be consistent with the observed distributions of these components in a number of connective tissues.
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Affiliation(s)
- Anthony J Hayes
- BioImaging Unit, Cardiff School of Biosciences, University of Cardiff, Cardiff, UK
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33
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Localised micro-mechanical stiffening in the ageing aorta. Mech Ageing Dev 2011; 132:459-67. [PMID: 21777602 PMCID: PMC3192262 DOI: 10.1016/j.mad.2011.07.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 05/09/2011] [Accepted: 07/05/2011] [Indexed: 12/31/2022]
Abstract
Age-related loss of tissue elasticity is a common cause of human morbidity and arteriosclerosis (vascular stiffening) is associated with the development of both fatal strokes and heart failure. However, in the absence of appropriate micro-mechanical testing methodologies, multiple structural remodelling events have been proposed as the cause of arteriosclerosis. Therefore, using a model of ageing in female sheep aorta (young: <18 months, old: >8 years) we: (i) quantified age-related macro-mechanical stiffness, (ii) localised in situ micro-metre scale changes in acoustic wave speed (a measure of tissue stiffness) and (iii) characterised collagen and elastic fibre remodelling. With age, there was an increase in both macro-mechanical stiffness and mean microscopic wave speed (and hence stiffness; young wave speed: 1701 ± 1 m s−1, old wave speed: 1710 ± 1 m s−1, p < 0.001) which was localized to collagen fibril-rich regions located between large elastic lamellae. These micro-mechanical changes were associated with increases in both collagen and elastic fibre content (collagen tissue area, young: 31 ± 2%, old: 40 ± 4%, p < 0.05; elastic fibre tissue area, young: 55 ± 3%, old: 69 ± 4%, p < 0.001). Localised collagen fibrosis may therefore play a key role in mediating age-related arteriosclerosis. Furthermore, high frequency scanning acoustic microscopy is capable of co-localising micro-mechanical and micro-structural changes in ageing tissues.
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Tissue Engineering of Blood Vessels: Functional Requirements, Progress, and Future Challenges. Cardiovasc Eng Technol 2011. [PMID: 23181145 DOI: 10.1007/s13239-011-0049-3] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Vascular disease results in the decreased utility and decreased availability of autologus vascular tissue for small diameter (< 6 mm) vessel replacements. While synthetic polymer alternatives to date have failed to meet the performance of autogenous conduits, tissue-engineered replacement vessels represent an ideal solution to this clinical problem. Ongoing progress requires combined approaches from biomaterials science, cell biology, and translational medicine to develop feasible solutions with the requisite mechanical support, a non-fouling surface for blood flow, and tissue regeneration. Over the past two decades interest in blood vessel tissue engineering has soared on a global scale, resulting in the first clinical implants of multiple technologies, steady progress with several other systems, and critical lessons-learned. This review will highlight the current inadequacies of autologus and synthetic grafts, the engineering requirements for implantation of tissue-engineered grafts, and the current status of tissue-engineered blood vessel research.
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Patel D, Menon R, Taite LJ. Self-Assembly of Elastin-Based Peptides into the ECM: the Importance of Integrins and the Elastin Binding Protein in Elastic Fiber Assembly. Biomacromolecules 2010; 12:432-40. [DOI: 10.1021/bm101214f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Dhaval Patel
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
| | - Rohan Menon
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
| | - Lakeshia J. Taite
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
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36
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Keire PA, L'Heureux N, Vernon RB, Merrilees MJ, Starcher B, Okon E, Dusserre N, McAllister TN, Wight TN. Expression of versican isoform V3 in the absence of ascorbate improves elastogenesis in engineered vascular constructs. Tissue Eng Part A 2010; 16:501-12. [PMID: 19712046 DOI: 10.1089/ten.tea.2009.0129] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
A promising method to fabricate tissue-engineered blood vessels is to have cells synthesize the supportive extracellular matrix scaffold of the tissue-engineered blood vessel; however, a shortcoming of this method has been limited elastogenesis. Previously, we found that arterial smooth muscle cells (ASMCs) produced significant quantities of elastin when transduced with splice variant 3 of the proteoglycan versican (V3). In this study, we assessed whether elastogenesis and the structural properties of entirely cell-derived engineered vascular constructs could be improved by the incorporation of V3-transduced rat ASMCs. After 18 weeks of culture, V3 constructs had more tropoelastin, more elastin crosslinks, higher burst strengths, greater elasticity, and thicker collagen fiber bundles compared with empty-vector controls. The expression of elastin and elastin-associated proteins was increased in V3 and control ASMC monolayer cultures when ascorbic acid, which promotes collagen synthesis and inhibits elastogenesis, was removed from the medium. Engineered vascular constructs with ascorbate withdrawn for 14 weeks, after an initial 4-week exposure to ascorbate, exhibited increased elastin, desmosine content, elasticity, and burst strength compared with constructs exposed continuously to ascorbate. Our results show that V3 coupled with limited exposure to ascorbate promotes elastogenesis and improves the structural and functional properties of engineered vascular constructs.
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Affiliation(s)
- Paul A Keire
- The Hope Heart Program, Benaroya Research Institute at Virginia Mason, Seattle, Washington, USA
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37
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Jakab K, Marga F, Norotte C, Murphy K, Vunjak-Novakovic G, Forgacs G. Tissue engineering by self-assembly and bio-printing of living cells. Biofabrication 2010; 2:022001. [PMID: 20811127 PMCID: PMC3635954 DOI: 10.1088/1758-5082/2/2/022001] [Citation(s) in RCA: 323] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Biofabrication of living structures with desired topology and functionality requires the interdisciplinary effort of practitioners of the physical, life and engineering sciences. Such efforts are being undertaken in many laboratories around the world. Numerous approaches are pursued, such as those based on the use of natural or artificial scaffolds, decellularized cadaveric extracellular matrices and, most lately, bioprinting. To be successful in this endeavor, it is crucial to provide in vitro micro-environmental clues for the cells resembling those in the organism. Therefore, scaffolds, populated with differentiated cells or stem cells, of increasing complexity and sophistication are being fabricated. However, no matter how sophisticated scaffolds are, they can cause problems stemming from their degradation, eliciting immunogenic reactions and other a priori unforeseen complications. It is also being realized that ultimately the best approach might be to rely on the self-assembly and self-organizing properties of cells and tissues and the innate regenerative capability of the organism itself, not just simply prepare tissue and organ structures in vitro followed by their implantation. Here we briefly review the different strategies for the fabrication of three-dimensional biological structures, in particular bioprinting. We detail a fully biological, scaffoldless, print-based engineering approach that uses self-assembling multicellular units as bio-ink particles and employs early developmental morphogenetic principles, such as cell sorting and tissue fusion.
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Affiliation(s)
- Karoly Jakab
- Department of Physics & Astronomy, University of Missouri, Columbia, MO 65211, USA
| | - Francoise Marga
- Department of Physics & Astronomy, University of Missouri, Columbia, MO 65211, USA
| | - Cyrille Norotte
- Department of Biology, University of Missouri, Columbia, MO 65211, USA
| | - Keith Murphy
- Organovo, Inc., 5871 Oberlin Drive, San Diego, CA 92121, USA
| | | | - Gabor Forgacs
- Department of Physics & Astronomy, University of Missouri, Columbia, MO 65211, USA
- Department of Biology, University of Missouri, Columbia, MO 65211, USA
- Department of Biomedical Engineering, University of Missouri, Columbia, MO 65211, USA
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38
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Kothapalli CR, Ramamurthi A. Lysyl oxidase enhances elastin synthesis and matrix formation by vascular smooth muscle cells. J Tissue Eng Regen Med 2010; 3:655-61. [PMID: 19813219 DOI: 10.1002/term.214] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Lysyl oxidase (LOX) is a copper-dependent enzyme that initiates covalent crosslinking of elastin precursors by oxidizing peptidyl lysine to aminoadipic semi-aldehydes. Previous studies have shown LOX deficiency to affect crosslinking of elastin and collagen in vivo, resulting in disorganized connective tissue formation. In this study, we investigated the utility of exogenously supplemented LOX peptides (50-100 microl/well) to elastin synthesis, crosslinking efficiency and matrix deposition in adult rat aortic smooth muscle cell (RASMC) cultures. Additionally, we also examined the role of LOX peptides on SMC proliferation and matrix metalloproteinase (MMP) synthesis in these cultures. Highly purified bovine aorta LOX peptide was found to increase matrix elastin synthesis by 40-80% to that in control cultures in a dose-dependent manner, while the crosslinking efficiency significantly (as measured by the ratio of matrix elastin protein to the total elastin protein synthesized) improved to 45-55% of total elastin synthesized under these conditions. However, LOX peptides affected neither SMC proliferation relative to controls, nor elastin precursor (tropoelastin) synthesis, nor the total elastin synthesis on a per-cell basis. In general, LOX peptides also did not affect MMP-2 and MMP-9 activities relative to control cultures, except for MMP-9 activity suppression at a higher LOX dose, suggesting that these LOX peptide cues could be safely used to enhance tropoelastin crosslinking into matrix structures and elastin matrix yield, within tissue-engineered constructs, a major challenge in the field.
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39
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Liu H, Xu W, Liu X, Xu J, Li W, Liu X. Effects of superfine silk protein powders on mechanical properties of wet-spun polyurethane fibers. J Appl Polym Sci 2009. [DOI: 10.1002/app.30515] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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40
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Sherratt MJ. Tissue elasticity and the ageing elastic fibre. AGE (DORDRECHT, NETHERLANDS) 2009; 31:305-25. [PMID: 19588272 PMCID: PMC2813052 DOI: 10.1007/s11357-009-9103-6] [Citation(s) in RCA: 203] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 06/08/2009] [Indexed: 04/16/2023]
Abstract
The ability of elastic tissues to deform under physiological forces and to subsequently release stored energy to drive passive recoil is vital to the function of many dynamic tissues. Within vertebrates, elastic fibres allow arteries and lungs to expand and contract, thus controlling variations in blood pressure and returning the pulmonary system to a resting state. Elastic fibres are composite structures composed of a cross-linked elastin core and an outer layer of fibrillin microfibrils. These two components perform distinct roles; elastin stores energy and drives passive recoil, whilst fibrillin microfibrils direct elastogenesis, mediate cell signalling, maintain tissue homeostasis via TGFβ sequestration and potentially act to reinforce the elastic fibre. In many tissues reduced elasticity, as a result of compromised elastic fibre function, becomes increasingly prevalent with age and contributes significantly to the burden of human morbidity and mortality. This review considers how the unique molecular structure, tissue distribution and longevity of elastic fibres pre-disposes these abundant extracellular matrix structures to the accumulation of damage in ageing dermal, pulmonary and vascular tissues. As compromised elasticity is a common feature of ageing dynamic tissues, the development of strategies to prevent, limit or reverse this loss of function will play a key role in reducing age-related morbidity and mortality.
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Affiliation(s)
- Michael J Sherratt
- Tissue Injury and Repair Group, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK.
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41
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Bax DV, Rodgers UR, Bilek MMM, Weiss AS. Cell adhesion to tropoelastin is mediated via the C-terminal GRKRK motif and integrin alphaVbeta3. J Biol Chem 2009; 284:28616-23. [PMID: 19617625 DOI: 10.1074/jbc.m109.017525] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Elastin fibers are predominantly composed of the secreted monomer tropoelastin. This protein assembly confers elasticity to all vertebrate elastic tissues including arteries, lung, skin, vocal folds, and elastic cartilage. In this study we examined the mechanism of cell interactions with recombinant human tropoelastin. Cell adhesion to human tropoelastin was divalent cation-dependent, and the inhibitory anti-integrin alpha(V)beta(3) antibody LM609 inhibited cell spreading on tropoelastin, identifying integrin alpha(V)beta(3) as the major fibroblast cell surface receptor for human tropoelastin. Cell adhesion was unaffected by lactose and heparin sulfate, indicating that the elastin-binding protein and cell surface glycosaminoglycans are not involved. The C-terminal GRKRK motif of tropoelastin can bind to cells in a divalent cation-dependent manner, identifying this as an integrin binding motif required for cell adhesion.
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Affiliation(s)
- Daniel V Bax
- Applied and Plasma Physics, School of Physics, University of Sydney, Sydney, New South Wales 2006, Australia.
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42
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Kothapalli CR, Taylor PM, Smolenski RT, Yacoub MH, Ramamurthi A. Transforming growth factor beta 1 and hyaluronan oligomers synergistically enhance elastin matrix regeneration by vascular smooth muscle cells. Tissue Eng Part A 2009; 15:501-11. [PMID: 18847364 PMCID: PMC2810272 DOI: 10.1089/ten.tea.2008.0040] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Accepted: 05/21/2008] [Indexed: 01/19/2023] Open
Abstract
Elastin is a vital structural and regulatory matrix protein that plays an important role in conferring elasticity to blood vessel wall. Previous tissue engineering approaches to regenerate elastin in situ or within tissue engineering constructs are curtailed by innate poor elastin synthesis potential by adult vascular smooth muscle cells (SMCs). Currently, we seek to develop cellular cues to enhance tropoelastin synthesis and improve elastin matrix yield, stability, and ultrastructure. Our earlier studies attest to the elastogenic utility of hyaluronan (HA)-based cellular cues, though their effects are fragment size dependent and dose dependent, with HA oligomers deemed most elastogenic. We presently show transforming growth factor beta 1 (TGF-beta1) and HA oligomers, when provided concurrently, to synergistically and dramatically improve elastin matrix regeneration by adult vascular SMCs. Together, these cues suppress SMC proliferation, enhance synthesis of tropoelastin (8-fold) and matrix elastin protein (5.5-fold), and also improve matrix elastin yield (45% of total elastin vs. 10% for nonadditive controls), possibly by more efficient recruitment of tropoelastin for crosslinking. The density of desmosine crosslinks within the elastin matrix was itself attenuated, although the cues together modestly increased production and activity of the elastin crosslinking enzyme, lysyl oxidase. TGF-beta1 and HA oligomers together induced much greater assembly of mature elastin fibers than they did separately, and did not induce matrix calcification. The present outcomes might be great utility to therapeutic regeneration of elastin matrix networks in situ within elastin-compromised vessels, and within tissue-engineered vascular graft replacements.
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Affiliation(s)
| | - Patricia M. Taylor
- Heart Science Center, National Heart and Lung Institute, Imperial College London at Harefield Hospital, Harefield, Middlesex, United Kingdom
| | - Ryszard T. Smolenski
- Heart Science Center, National Heart and Lung Institute, Imperial College London at Harefield Hospital, Harefield, Middlesex, United Kingdom
| | - Magdi H. Yacoub
- Heart Science Center, National Heart and Lung Institute, Imperial College London at Harefield Hospital, Harefield, Middlesex, United Kingdom
| | - Anand Ramamurthi
- Clemson University-Medical University of South Carolina Bioengineering Program, Charleston, South Carolina
- Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston, South Carolina
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43
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Kothapalli CR, Ramamurthi A. Copper nanoparticle cues for biomimetic cellular assembly of crosslinked elastin fibers. Acta Biomater 2009; 5:541-53. [PMID: 18849207 DOI: 10.1016/j.actbio.2008.09.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Revised: 07/31/2008] [Accepted: 09/03/2008] [Indexed: 11/18/2022]
Abstract
Elastin, a structural protein distributed in the extracellular matrix of vascular tissues, is critical to maintaining the elastic stability and mechanical properties of blood vessels, as well as regulating cell-signaling pathways involved in vascular injury response and morphogenesis. Pathological degradation of vascular elastin or its malformation within native vessels and the poor ability to tissue-engineer elastin-rich vascular replacements due to innately poor elastin synthesis by adult vascular cells can compromise vascular homeostasis, and must thus be addressed. Our recent studies attest to the utility of hyaluronan (HA) oligomers for elastin synthesis and organization by adult vascular smooth muscle cells (SMCs), though the elastin matrix yields in these cases were quite low relative to total elastin produced. Thus, in this study, we investigated the utility of copper (Cu(2+)) ions to enhance cellular elastin deposition, crosslinking and maturation into structural fibers. Copper nanoparticles (CuNPs; 80-100 nm) in the dose range of 1-100 ng ml(-1) were tested for Cu(2+) ion release, and based on mathematical modeling of their release profiles, CuNPs (1, 10, and 400 ng ml(-1)) were chosen for supplementation to adult SMC cultures. The 400 ng ml(-1) dose of CuNPs cumulatively delivered Cu(2+) doses in the range of 0.1 M, over the 21 day culture period. It was observed that while exogenous CuNP supplements do not up-regulate tropoelastin production by vascular SMCs, they promoted formation of crosslinked elastin matrices. The deposition of crosslinked matrix elastin was further improved by the additional presence of HA oligomers in these cultures. Immunofluorescence imaging and structural analysis of the isolated elastin matrices indicate that amorphous elastin clumps were formed within non-additive control cultures, while aggregating elastin fibrils were observed within SMC cultures treated with CuNPs (1-10 ng ml(-1)) alone or together with HA oligomers. The presence of 400 ng ml(-1) of CuNPs concurrent with HA oligomers furthered aggregation of these elastin fibrils into mature fibers with diameters ranging from 200 to 500 nm. Ultrastructural analysis of elastin matrix within cultures treated with HA oligomers and 400 ng ml(-1) of CuNPs suggest that elastin matrix deposition as stimulated by Cu(2+) ions proceeds via a fibrillin-mediated assembly process, with enhanced crosslinking occurring via stimulation of lysyl oxidase. Overall, the data suggest that CuNPs and HA oligomers are highly useful for regenerating crosslinked, fibrillar elastin matrices by adult vascular SMCs. These results have immense utility in tissue-engineering vascular replacements.
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MESH Headings
- Animals
- Blotting, Western
- Cell Proliferation
- Cells, Cultured
- Copper
- Dose-Response Relationship, Drug
- Elastin/biosynthesis
- Elastin/chemistry
- Elastin/metabolism
- Enzyme-Linked Immunosorbent Assay
- Fibrillins
- Fluorescent Antibody Technique
- Metal Nanoparticles
- Microfilament Proteins/metabolism
- Microscopy, Electron, Scanning
- Microscopy, Electron, Transmission
- Molecular Mimicry
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Rats
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Affiliation(s)
- Chandrasekhar R Kothapalli
- Clemson University-Medical University of South Carolina Bioengineering Program, 173 Ashley Avenue, BSB 601, Charleston, SC 29425, USA
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44
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Biomolecular analysis of elastic fibre molecules. Methods 2008; 45:42-52. [DOI: 10.1016/j.ymeth.2008.01.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Accepted: 01/30/2008] [Indexed: 11/18/2022] Open
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45
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Affiliation(s)
- Magdi Yacoub
- Heart Science Centre, Harefield Hospital, Harefield, Middlesex UB9 6 JH, UK.
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46
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Stephan S, Ball SG, Williamson M, Bax DV, Lomas A, Shuttleworth CA, Kielty CM. Cell-matrix biology in vascular tissue engineering. J Anat 2006; 209:495-502. [PMID: 17005021 PMCID: PMC2100353 DOI: 10.1111/j.1469-7580.2006.00633.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2006] [Indexed: 12/18/2022] Open
Abstract
We are developing biocompatible small-calibre vascular substitutes based on polymeric scaffolds that incorporate cell-matrix signals to enhance vascular cell attachment and function. Our graft scaffold comprises an outer electrostatically spun porous polyurethane layer seeded with smooth muscle cells, and a luminal polycaprolactone layer for endothelial cell attachment. Vascular cell adhesion properties of three vascular elastic fibre molecules, tropoelastin, fibrillin-1 and fibulin-5, have been defined, and adhesion fragments optimized. These fragments are being used to coat the scaffolds to enhance luminal endothelial cell attachment, and to regulate smooth muscle cell attachment and function. Tropoelastin-based cell seeding materials are also being developed. In this way, vascular cell-matrix biology is enhancing graft design.
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Affiliation(s)
- Simon Stephan
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, UK
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