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Potential of Biodegradable Synthetic Polymers for Use in Small-diameter Vascular Engineering. Macromol Res 2022. [DOI: 10.1007/s13233-022-0056-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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2
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Fang S, Ellman DG, Andersen DC. Review: Tissue Engineering of Small-Diameter Vascular Grafts and Their In Vivo Evaluation in Large Animals and Humans. Cells 2021; 10:713. [PMID: 33807009 PMCID: PMC8005053 DOI: 10.3390/cells10030713] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/10/2021] [Accepted: 03/15/2021] [Indexed: 12/15/2022] Open
Abstract
To date, a wide range of materials, from synthetic to natural or a mixture of these, has been explored, modified, and examined as small-diameter tissue-engineered vascular grafts (SD-TEVGs) for tissue regeneration either in vitro or in vivo. However, very limited success has been achieved due to mechanical failure, thrombogenicity or intimal hyperplasia, and improvements of the SD-TEVG design are thus required. Here, in vivo studies investigating novel and relative long (10 times of the inner diameter) SD-TEVGs in large animal models and humans are identified and discussed, with emphasis on graft outcome based on model- and graft-related conditions. Only a few types of synthetic polymer-based SD-TEVGs have been evaluated in large-animal models and reflect limited success. However, some polymers, such as polycaprolactone (PCL), show favorable biocompatibility and potential to be further modified and improved in the form of hybrid grafts. Natural polymer- and cell-secreted extracellular matrix (ECM)-based SD-TEVGs tested in large animals still fail due to a weak strength or thrombogenicity. Similarly, native ECM-based SD-TEVGs and in-vitro-developed hybrid SD-TEVGs that contain xenogeneic molecules or matrix seem related to a harmful graft outcome. In contrast, allogeneic native ECM-based SD-TEVGs, in-vitro-developed hybrid SD-TEVGs with allogeneic banked human cells or isolated autologous stem cells, and in-body tissue architecture (IBTA)-based SD-TEVGs seem to be promising for the future, since they are suitable in dimension, mechanical strength, biocompatibility, and availability.
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Affiliation(s)
- Shu Fang
- Laboratory of Molecular and Cellular Cardiology, Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, J. B. Winsløwsvej 25, 5000 Odense C, Denmark; (D.G.E.); (D.C.A.)
- The Danish Regenerative Center, Odense University Hospital, J. B. Winsløwsvej 4, 5000 Odense C, Denmark
- Institute of Clinical Research, University of Southern Denmark, J. B. Winsløwsvej 19, 5000 Odense C, Denmark
| | - Ditte Gry Ellman
- Laboratory of Molecular and Cellular Cardiology, Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, J. B. Winsløwsvej 25, 5000 Odense C, Denmark; (D.G.E.); (D.C.A.)
- Institute of Clinical Research, University of Southern Denmark, J. B. Winsløwsvej 19, 5000 Odense C, Denmark
| | - Ditte Caroline Andersen
- Laboratory of Molecular and Cellular Cardiology, Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, J. B. Winsløwsvej 25, 5000 Odense C, Denmark; (D.G.E.); (D.C.A.)
- The Danish Regenerative Center, Odense University Hospital, J. B. Winsløwsvej 4, 5000 Odense C, Denmark
- Institute of Clinical Research, University of Southern Denmark, J. B. Winsløwsvej 19, 5000 Odense C, Denmark
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3
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Regulation of endothelial functionality through direct and immunomodulatory effects by Ni-Ti-O nanospindles on NiTi alloy. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2021; 123:112007. [PMID: 33812627 DOI: 10.1016/j.msec.2021.112007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 02/08/2021] [Accepted: 02/23/2021] [Indexed: 12/25/2022]
Abstract
Stent implantation has become one of the most widely used methods for the treatment of cardiovascular diseases. However, endothelial dysfunction and abnormal inflammatory response following implantation may lead to delayed re-endothelialization, resulting in vascular restenosis and stent thrombus. To address the concerns, we constructed nanospindles composed of TiO2 and Ti4Ni2O through hydrothermal treatment of amorphous Ni-Ti-O nanopores anodically grown on NiTi alloy. The results show the treatment can significantly improve hydrophilicity and reduce Ni ion release, essentially independent of hydrothermal duration. The nanospindle surfaces not only promote the expression of endothelial functionality but also activate macrophages to induce a favorable immune response, downregulate pro-inflammatory M1 markers and upregulate pro-healing M2 markers. Moreover, nitric oxide (NO) synthesis, VEGF secretion, and migration of endothelial cells are enhanced after cultured in macrophage conditioned medium. The nanospindles thus are promising as vascular stent coatings to promote re-endothelization.
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Scarcello E, Lison D. Are Fe-Based Stenting Materials Biocompatible? A Critical Review of In Vitro and In Vivo Studies. J Funct Biomater 2019; 11:jfb11010002. [PMID: 31877701 PMCID: PMC7151573 DOI: 10.3390/jfb11010002] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/18/2019] [Accepted: 12/19/2019] [Indexed: 02/06/2023] Open
Abstract
Fe-based materials have increasingly been considered for the development of biodegradable cardiovascular stents. A wide range of in vitro and in vivo studies should be done to fully evaluate their biocompatibility. In this review, we summarized and analyzed the findings and the methodologies used to assess the biocompatibility of Fe materials. The majority of investigators drew conclusions about in vitro Fe toxicity based on indirect contact results. The setup applied in these tests seems to overlook the possible effects of Fe corrosion and does not allow for understanding of the complexity of released chemical forms and their possible impact on tissue. It is in particular important to ensure that test setups or interpretations of in vitro results do not hide some important mechanisms, leading to inappropriate subsequent in vivo experiments. On the other hand, the sample size of existing in vivo implantations is often limited, and effects such as local toxicity or endothelial function are not deeply scrutinized. The main advantages and limitations of in vitro design strategies applied in the development of Fe-based alloys and the correlation with in vivo studies are discussed. It is evident from this literature review that we are not yet ready to define an Fe-based material as safe or biocompatible.
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Sánchez PF, Brey EM, Briceño JC. Endothelialization mechanisms in vascular grafts. J Tissue Eng Regen Med 2018; 12:2164-2178. [PMID: 30079631 DOI: 10.1002/term.2747] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 05/18/2018] [Accepted: 07/09/2018] [Indexed: 12/12/2022]
Abstract
Despite the wide variety of tissue-engineered vascular grafts that are currently being developed, autologous vessels, such as the saphenous vein, are still the gold standard grafts for surgical treatment of vascular disease. Recently developed technologies have shown promising results in preclinical studies, but they still do not overcome the issues that native vessels present, and only a few have made the transition into clinical use. The endothelial lining is a key aspect for the success or failure of the grafts, especially on smaller diameter grafts (<5 mm). However, during the design and evaluation of the grafts, the mechanisms for the formation of this layer are not commonly examined. Therefore, a significant amount of established research might not be relevant to the clinical context, due to important differences that exist between the vascular regeneration mechanisms found in animal models and humans. This article reviews current knowledge about endothelialization mechanisms that have been so far identified: in vitro seeding, transanastomotic growth, transmural infiltration, and fallout endothelialization. Emphasis is placed on the models used for study of theses mechanisms and their effects on the development of tissue-engineering vascular conduits.
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Affiliation(s)
- Paolo F Sánchez
- Department of Biomedical Engineering, Universidad de los Andes, Bogotá, Colombia
| | - Eric M Brey
- Biomedical Engineering, University of Texas at San Antonio, San Antonio, Texas.,Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois.,Research Service, South Texas Veterans Health Care System, San Antonio, Texas
| | - Juan Carlos Briceño
- Department of Biomedical Engineering, Universidad de los Andes, Bogotá, Colombia.,Research Department, Fundación Cardioinfantil Instituto de Cardiología, Bogotá, Colombia
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6
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Xie Y, Guan Y, Kim SH, King MW. The mechanical performance of weft-knitted/electrospun bilayer small diameter vascular prostheses. J Mech Behav Biomed Mater 2016; 61:410-418. [DOI: 10.1016/j.jmbbm.2016.04.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 04/04/2016] [Accepted: 04/06/2016] [Indexed: 11/16/2022]
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7
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Zhang S, Zhang X, Tian Y, Meng Y. Theoretical and experimental study of the porous film using quartz crystal microbalance. BIOMICROFLUIDICS 2016; 10:024127. [PMID: 27190562 PMCID: PMC4851629 DOI: 10.1063/1.4946876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 04/04/2016] [Indexed: 06/05/2023]
Abstract
The self-assembled multilayers have been studied by many researchers to modify the surfaces of artificial implants for increasing biocompatibility. The accurate mechanical properties of the film can only be obtained from the experimental results using appropriate theoretical models. As the film is composed of both solid polymers and fluid, this paper proposes a two-phase model. Based on the volume average method, the momentum equations are derived for both solid and liquid phases. In order to test our model, we built the porous film on the gold chip of the quartz crystal microbalance using the layer-by-layer method. The buildup process is based on the electrostatic interactions between anionic sodium hyaluronate and cationic chitosan by imitating the endothelial surface layer. By fitting our model to the experimental changes of the resonant frequency and dissipation factor, we get reasonable values of the film thickness, the porosity, the shear modulus of the solid phase, and the permeability. Compared with the existing models, the newly introduced permeability is an important property of the porous layer affecting the values of other parameters. Our model can provide more intrinsic properties of the self-assembled polymeric network and explain its interaction with the permeating fluid.
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Affiliation(s)
- Songpeng Zhang
- State Key Laboratory of Tribology, Tsinghua University , Beijing 100084, China
| | - Xiangjun Zhang
- State Key Laboratory of Tribology, Tsinghua University , Beijing 100084, China
| | - Yu Tian
- State Key Laboratory of Tribology, Tsinghua University , Beijing 100084, China
| | - Yonggang Meng
- State Key Laboratory of Tribology, Tsinghua University , Beijing 100084, China
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8
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Uthamaraj S, Tefft BJ, Hlinomaz O, Sandhu GS, Dragomir-Daescu D. Ferromagnetic Bare Metal Stent for Endothelial Cell Capture and Retention. J Vis Exp 2015. [PMID: 26436434 DOI: 10.3791/53100] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Rapid endothelialization of cardiovascular stents is needed to reduce stent thrombosis and to avoid anti-platelet therapy which can reduce bleeding risk. The feasibility of using magnetic forces to capture and retain endothelial outgrowth cells (EOC) labeled with super paramagnetic iron oxide nanoparticles (SPION) has been shown previously. But this technique requires the development of a mechanically functional stent from a magnetic and biocompatible material followed by in-vitro and in-vivo testing to prove rapid endothelialization. We developed a weakly ferromagnetic stent from 2205 duplex stainless steel using computer aided design (CAD) and its design was further refined using finite element analysis (FEA). The final design of the stent exhibited a principal strain below the fracture limit of the material during mechanical crimping and expansion. One hundred stents were manufactured and a subset of them was used for mechanical testing, retained magnetic field measurements, in-vitro cell capture studies, and in-vivo implantation studies. Ten stents were tested for deployment to verify if they sustained crimping and expansion cycle without failure. Another 10 stents were magnetized using a strong neodymium magnet and their retained magnetic field was measured. The stents showed that the retained magnetism was sufficient to capture SPION-labeled EOC in our in-vitro studies. SPION-labeled EOC capture and retention was verified in large animal models by implanting 1 magnetized stent and 1 non-magnetized control stent in each of 4 pigs. The stented arteries were explanted after 7 days and analyzed histologically. The weakly magnetic stents developed in this study were capable of attracting and retaining SPION-labeled endothelial cells which can promote rapid healing.
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Affiliation(s)
| | | | - Ota Hlinomaz
- Department of Cardioangiology, ICRC, St. Anne's University Hospital
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9
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Zhou Q, Li L, Li J. Stem cells with decellularized liver scaffolds in liver regeneration and their potential clinical applications. Liver Int 2015; 35:687-94. [PMID: 24797694 DOI: 10.1111/liv.12581] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 04/27/2014] [Indexed: 02/13/2023]
Abstract
End-stage hepatic failure is a potentially life-threatening condition for which orthotopic liver transplantation (OLT) is the only effective treatment. However, a shortage of available donor organs for transplantation each year results in the death of many patients waiting for liver transplantation. Cell-based therapies and hepatic tissue engineering have been considered as alternatives to liver transplantation. However, primary hepatocyte transplantation has rarely produced therapeutic effects because mature hepatocytes cannot be effectively expanded in vitro, and the availability of hepatocytes is often limited by shortages of donor organs. Decellularization is an attractive technique for scaffold preparation in stem cell-based liver engineering, as the resulting material can potentially retain the liver architecture, native vessel network and specific extracellular matrix (ECM). Thus, the reconstruction of functional and practical liver tissue using decellularized scaffolds becomes possible. This review focuses on the current understanding of liver tissue engineering, whole-organ liver decellularization techniques, cell sources for recellularization and potential clinical applications and challenges.
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Affiliation(s)
- Qian Zhou
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, 79 Qingchun Rd., Hangzhou, 310003, China
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10
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Li X, Yuan S, Chen S, Luo R, Xiong K, Yang Z, Wang J, Huang N. Proliferation and functionality of human umbilical vein endothelial cells on angiopoietin-1 immobilized 316L stainless steel. J Mater Chem B 2015; 3:8717-8728. [DOI: 10.1039/c5tb01313e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An angiopoietin-1 functionalized surface was establishedviapolydopamine coating and regulated HUVECs survival, proliferation and function.
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Affiliation(s)
- Xin Li
- Key Lab. of Advanced Technology for Materials of Education Ministry
- Southwest Jiaotong University
- Chengdu 610031
- China
- The Institute of Biomaterials and Surface Engineering
| | - Shuheng Yuan
- Key Lab. of Advanced Technology for Materials of Education Ministry
- Southwest Jiaotong University
- Chengdu 610031
- China
- The Institute of Biomaterials and Surface Engineering
| | - Si Chen
- Key Lab. of Advanced Technology for Materials of Education Ministry
- Southwest Jiaotong University
- Chengdu 610031
- China
- The Institute of Biomaterials and Surface Engineering
| | - Rifang Luo
- Key Lab. of Advanced Technology for Materials of Education Ministry
- Southwest Jiaotong University
- Chengdu 610031
- China
- The Institute of Biomaterials and Surface Engineering
| | - Kaiqin Xiong
- Key Lab. of Advanced Technology for Materials of Education Ministry
- Southwest Jiaotong University
- Chengdu 610031
- China
| | - Zhilu Yang
- Key Lab. of Advanced Technology for Materials of Education Ministry
- Southwest Jiaotong University
- Chengdu 610031
- China
| | - Jin Wang
- Key Lab. of Advanced Technology for Materials of Education Ministry
- Southwest Jiaotong University
- Chengdu 610031
- China
| | - Nan Huang
- Key Lab. of Advanced Technology for Materials of Education Ministry
- Southwest Jiaotong University
- Chengdu 610031
- China
- The Institute of Biomaterials and Surface Engineering
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11
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Uthamaraj S, Tefft BJ, Klabusay M, Hlinomaz O, Sandhu GS, Dragomir-Daescu D. Design and validation of a novel ferromagnetic bare metal stent capable of capturing and retaining endothelial cells. Ann Biomed Eng 2014; 42:2416-24. [PMID: 25138164 DOI: 10.1007/s10439-014-1088-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 08/04/2014] [Indexed: 11/25/2022]
Abstract
Rapid healing of vascular stents is important for avoiding complications associated with stent thrombosis, restenosis, and bleeding related to antiplatelet drugs. Magnetic forces can be used to capture iron-labeled endothelial cells immediately following stent implantation, thereby promoting healing. This strategy requires the development of a magnetic stent that is biocompatible and functional. We designed a stent from the weakly ferromagnetic 2205 stainless steel using finite element analysis. The final design exhibited a principal strain below the fracture limit of 30% during crimping and expansion. Ten stents were fabricated and validated experimentally for fracture resistance. Another 10 stents magnetized with a neodymium magnet showed a magnetic field in the range of 100-750 mG. The retained magnetism was sufficiently strong to capture magnetically-labeled endothelial cells on the stent surfaces during in vitro studies. Magnetically-labeled endothelial cell capture was also verified in vivo after 7 days following coronary implantation in 4 pigs using histological analysis. Images of the stented blood vessels showed uniform endothelium formation on the stent surfaces. In conclusion, we have designed a ferromagnetic bare metal stent from 2205 stainless steel that is functional, biocompatible, and able to capture and retain magnetically-labeled endothelial cells in order to promote rapid stent healing.
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Affiliation(s)
- Susheil Uthamaraj
- Division of Engineering, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
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12
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Regenerative implants for cardiovascular tissue engineering. Transl Res 2014; 163:321-41. [PMID: 24589506 DOI: 10.1016/j.trsl.2014.01.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 01/27/2014] [Accepted: 01/27/2014] [Indexed: 01/22/2023]
Abstract
A fundamental problem that affects the field of cardiovascular surgery is the paucity of autologous tissue available for surgical reconstructive procedures. Although the best results are obtained when an individual's own tissues are used for surgical repair, this is often not possible as a result of pathology of autologous tissues or lack of a compatible replacement source from the body. The use of prosthetics is a popular solution to overcome shortage of autologous tissue, but implantation of these devices comes with an array of additional problems and complications related to biocompatibility. Transplantation offers another option that is widely used but complicated by problems related to rejection and donor organ scarcity. The field of tissue engineering represents a promising new option for replacement surgical procedures. Throughout the years, intensive interdisciplinary, translational research into cardiovascular regenerative implants has been undertaken in an effort to improve surgical outcome and better quality of life for patients with cardiovascular defects. Vascular, valvular, and heart tissue repair are the focus of these efforts. Implants for these neotissues can be divided into 2 groups: biologic and synthetic. These materials are used to facilitate the delivery of cells or drugs to diseased, damaged, or absent tissue. Furthermore, they can function as a tissue-forming device used to enhance the body's own repair mechanisms. Various preclinical studies and clinical trials using these advances have shown that tissue-engineered materials are a viable option for surgical repair, but require refinement if they are going to reach their clinical potential. With the growth and accomplishments this field has already achieved, meeting those goals in the future should be attainable.
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13
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Finosh GT, Jayabalan M. Regenerative therapy and tissue engineering for the treatment of end-stage cardiac failure: new developments and challenges. BIOMATTER 2014; 2:1-14. [PMID: 23507781 DOI: 10.4161/biom.19429] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Regeneration of myocardium through regenerative therapy and tissue engineering is appearing as a prospective treatment modality for patients with end-stage heart failure. Focusing on this area, this review highlights the new developments and challenges in the regeneration of myocardial tissue. The role of various cell sources, calcium ion and cytokine on the functional performance of regenerative therapy is discussed. The evolution of tissue engineering and the role of tissue matrix/scaffold, cell adhesion and vascularisation on tissue engineering of cardiac tissue implant are also discussed.
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Affiliation(s)
- G T Finosh
- Polymer Science Division, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Kerala, India
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14
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Bordenave L, Menu P, Baquey C. Developments towards tissue-engineered, small-diameter arterial substitutes. Expert Rev Med Devices 2014; 5:337-47. [DOI: 10.1586/17434440.5.3.337] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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15
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Abstract
This review outlines the current understanding of the interactions of titanium and its alloys with blood components, and the ways in which surface modification techniques can be used to alter the surface physicochemical and topographical features that determine blood-material interactions. Surface modification of the spontaneously formed titanium oxide surface layer is a highly attractive means of improving haemocompatibility without forgoing the advantageous mechanical and physical properties of titanium and its alloys. A number of surface modification techniques and treatment processes are discussed in the context of enhancing the haemocompatibility of titanium and its alloys, with a view to optimising the clinical efficacy of blood-contacting devices and materials.
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16
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Baumer Y, Funk D, Schlosshauer B. Does telomerase reverse transcriptase induce functional de-differentiation of human endothelial cells? Cell Mol Life Sci 2010; 67:2451-65. [PMID: 20352467 PMCID: PMC11115536 DOI: 10.1007/s00018-010-0349-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2009] [Revised: 02/26/2010] [Accepted: 03/09/2010] [Indexed: 01/05/2023]
Abstract
By counteracting the shortening of chromosome telomeres, telomerase reverse transcriptase (hTERT) prevents senescence and age-related cell death. Embryonic cells display a high telomerase activity that declines rapidly with cell differentiation. Conversely, de-differentiated tumor cells tend to re-express telomerase. In view of the controversial data on the reciprocal correlation between cell proliferation and differentiation, we questioned whether telomerase overexpression and the resulting immortalization would affect the functional phenotype of human endothelial cells. Our comparative analysis addressed (1) distinct cell adhesion to different ECM-proteins analyzed on miniaturized multisubstrate arrays (MSA), (2) protein expression of diverse markers, (3) the uptake of DiI-Ac-LDL, (4) the inflammatory response based on upregulation of ICAM-1, (5) tube formation, and (6) the barrier properties of cell monolayers in transfilter cultures. Our results, based on some 40 data sets, demonstrate that immortalization of primary endothelial cells by hTERT maintains the typical endothelial characteristics without any sign of functional de-differentiation.
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Affiliation(s)
- Yvonne Baumer
- NMI, Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstraße 55, 72770 Reutlingen, Germany
| | - Dorothee Funk
- NMI, Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstraße 55, 72770 Reutlingen, Germany
| | - Burkhard Schlosshauer
- NMI, Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstraße 55, 72770 Reutlingen, Germany
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Allen J, Khan S, Serrano MC, Ameer G. Characterization of Porcine Circulating Progenitor Cells: Toward a Functional Endothelium. Tissue Eng Part A 2008; 14:183-94. [DOI: 10.1089/ten.a.2007.0265] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Josephine Allen
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
| | - Sadiya Khan
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
| | | | - Guillermo Ameer
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
- Institute for BioNanotechnology in Medicine, Northwestern University, Evanston, Illinois
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18
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Leali D, Moroni E, Bussolino F, Presta M. Osteopontin Overexpression Inhibits in Vitro Re-endothelialization via Integrin Engagement. J Biol Chem 2007; 282:19676-84. [PMID: 17456474 DOI: 10.1074/jbc.m606938200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The extracellular matrix protein osteopontin (OPN) plays a nonredundant role in atherosclerosis and restenosis. Here we investigated the impact of OPN up-regulation in an in vitro model of re-endothelialization after mechanical injury of the endothelial cell monolayer. Murine aortic endothelial (MAE) cells interact via alpha(v) integrins with the integrin-binding Arg-Gly-Asp OPN sequence and adhere to immobilized OPN. On this basis, MAE cells were stably transfected with a wild-type OPN cDNA (OPN-MAE cells), with an OPN mutant lacking the Arg-Gly-Asp sequence (DeltaRGD-OPN-MAE cells), or with vector alone (mock-MAE cells). When compared with mock-MAE and DeltaRGD-OPN-MAE cells, OPN-MAE cells showed a reduced sprouting activity in fibrin gel, a reduced motility in a Boyden chamber assay, and a reduced capacity to repair the wounded monolayer. Accordingly, OPN-MAE cells at the edge of the wound were unable to form membrane ruffles, to reorganize their cytoskeleton, and to activate the focal adhesion kinase and the small GTPase Rac1, key regulators of the cell entry into the first phase of the cell migration cycle. Accordingly, wounded OPN-MAE cells failed to activate the intracellular signals RhoA and ERK1/2, involved in the later phases of the cell migration cycle. Also, parental MAE cells showed reduced re-endothelialization after wounding when seeded on immobilized OPN and exhibited increased adhesiveness to OPN-enriched extracellular matrix. In conclusion, OPN up-regulation impairs re-endothelialization by inhibiting the first phase of the cell migration cycle via alpha(v) integrin engagement by the extracellular matrix-immobilized protein. This may contribute to the adverse effects exerted by OPN in restenosis and atherosclerosis.
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Affiliation(s)
- Daria Leali
- Unit of General Pathology, Department of Biomedical Sciences and Biotechnology, School of Medicine, University of Brescia, 25123 Brescia, Italy
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19
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McGuigan AP, Sefton MV. The influence of biomaterials on endothelial cell thrombogenicity. Biomaterials 2007; 28:2547-71. [PMID: 17316788 PMCID: PMC1868518 DOI: 10.1016/j.biomaterials.2007.01.039] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Accepted: 01/31/2007] [Indexed: 01/01/2023]
Abstract
Driven by tissue engineering and regenerative medicine, endothelial cells are being used in combination with biomaterials in a number of applications for the purpose of improving blood compatibility and host integration. Endothelialized vascular grafts are beginning to be used clinically with some success in some centers, while endothelial seeding is being explored as a means of creating a vasculature within engineered tissues. The underlying assumption of this strategy is that when cultured on artificial biomaterials, a confluent layer of endothelial cells maintain their non-thrombogenic phenotype. In this review the existing knowledge base of endothelial cell thrombogenicity cultured on a number of different biomaterials is summarized. The importance of selecting appropriate endpoint measures that are most reflective of overall surface thrombogenicity is the focus of this review. Endothelial cells inhibit thrombosis through three interconnected regulatory systems (1) the coagulation cascade, (2) the cellular components of the blood such as leukocytes and platelets and (3) the complement cascade, and also through effects on fibrinolysis and vascular tone, the latter which influences blood flow. Thus, in order to demonstrate the thrombogenic benefit of seeding a biomaterial with EC, the conditions under which EC surfaces are more likely to exhibit lower thrombogenicity than unseeded biomaterial surfaces need to be consistent with the experimental context. The endpoints selected should be appropriate for the dominant thrombotic process that occurs under the given experimental conditions.
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Brewster L, Brey E, Greisler H. Cardiovascular gene delivery: The good road is awaiting. Adv Drug Deliv Rev 2006; 58:604-29. [PMID: 16769148 PMCID: PMC3337725 DOI: 10.1016/j.addr.2006.03.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Accepted: 03/24/2006] [Indexed: 01/13/2023]
Abstract
Atherosclerotic cardiovascular disease is a leading cause of death worldwide. Despite recent improvements in medical, operative, and endovascular treatments, the number of interventions performed annually continues to increase. Unfortunately, the durability of these interventions is limited acutely by thrombotic complications and later by myointimal hyperplasia followed by progression of atherosclerotic disease over time. Despite improving medical management of patients with atherosclerotic disease, these complications appear to be persisting. Cardiovascular gene therapy has the potential to make significant clinical inroads to limit these complications. This article will review the technical aspects of cardiovascular gene therapy; its application for promoting a functional endothelium, smooth muscle cell growth inhibition, therapeutic angiogenesis, tissue engineered vascular conduits, and discuss the current status of various applicable clinical trials.
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Affiliation(s)
- L.P. Brewster
- Department of Surgery, Loyola University Medical Center, Maywood, IL, 60153, USA
- Department of Cell Biology, Neurobiology, and Anatomy, Loyola University Medical Center, Maywood, IL, 60153, USA
| | - E.M. Brey
- Department of Surgery, Loyola University Medical Center, Maywood, IL, 60153, USA
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, 60616, USA
- Research and Surgical Services, Edward J. Hines Jr. V.A. Hospital, Hines, IL, 60141, USA
| | - H.P. Greisler
- Department of Surgery, Loyola University Medical Center, Maywood, IL, 60153, USA
- Department of Cell Biology, Neurobiology, and Anatomy, Loyola University Medical Center, Maywood, IL, 60153, USA
- Research and Surgical Services, Edward J. Hines Jr. V.A. Hospital, Hines, IL, 60141, USA
- Corresponding author. Loyola University Medical Center, Department of Surgery, 2160 South First Avenue, Maywood, IL, 60153, USA. Tel.: +1 708 216 8541; fax: +1 708 216 6300. (H.P. Greisler)
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21
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Gavalas VG, Berrocal MJ, Bachas LG. Enhancing the blood compatibility of ion-selective electrodes. Anal Bioanal Chem 2005; 384:65-72. [PMID: 16132141 DOI: 10.1007/s00216-005-0039-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Revised: 07/15/2005] [Accepted: 07/19/2005] [Indexed: 10/25/2022]
Abstract
In vivo monitoring of various analytes is important for many bioanalytical and biomedical applications. The crucial challenge in this type of applications is the interaction of the sensor with the host environment, which is qualitatively described by the term biocompatibility. This review discusses recent advances in methods and materials used for the improvement of the biocompatibility of ion-selective electrodes especially as it relates to their interaction with blood components.
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Affiliation(s)
- Vasilis G Gavalas
- Department of Chemistry and Center of Membrane Sciences, University of Kentucky, Lexington, KY 40506-0055, USA
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Brey EM, Uriel S, Greisler HP, McIntire LV. Therapeutic neovascularization: contributions from bioengineering. ACTA ACUST UNITED AC 2005; 11:567-84. [PMID: 15869435 DOI: 10.1089/ten.2005.11.567] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A number of pathological entities and surgical interventions could benefit from therapeutic stimulation of new blood vessel formation. Although strategies designed for promoting neovascularization have shown promise in preclinical models, translation to human application has met with limited success when angiogenesis is used as the single therapeutic mechanism. While clinical protocols continue to be optimized, a number of exciting new approaches are being developed. Bioengineering has played an important role in the progress of many of these innovative new strategies. In this review, we present a general outline of therapeutic neovascularization, with an emphasis on investigations using engineering principles to address this vexing clinical problem. In addition, we identify some limitations and suggest areas for future research.
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Affiliation(s)
- Eric M Brey
- Pritzker Institute of Biomedical Science and Engineering, Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, 60616, USA.
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Schwartz MA, Stone AL, Greer KA, Hoying JB, Williams SK. Gene expression in tissue associated with extracellular matrix modified ePTFE. J Biomed Mater Res A 2005; 73:30-8. [PMID: 15714498 DOI: 10.1002/jbm.a.30228] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Previous studies have established that surface modification of ePTFE with extracellular matrix molecules promotes vascularization within and around the implanted material. To understand the molecular basis of this tissue response to modified ePTFE, we analyzed large-scale gene expression in nonmodified and extracellular matrix-modified ePTFE-associated healing. Using a microarray containing 15,000 unique mouse cDNAs and an ANOVA-based analysis, we identified 789 genes related to cell signaling, inflammation, matrix remodeling, and proliferation that were differentially expressed across time, between modifications, or both. Genes were clustered based upon similarity in gene expression, producing 7 unique temporal super-patterns of expression. The clustered data revealed 3 general expression patterns unique to tissue surrounding the nonmodified ePTFE, while 6 unique expression patterns were associated with extracellular matrix-modified ePTFE. The more diverse expression patterns associated with extracellular matrix-modified ePTFE suggests that the tissue surrounding the extracellular matrix-modified ePTFE is more dynamic in terms of transcriptional activity. Taken together, these clusters serve as a "genetic fingerprint" for tissue healing in response to a specific material or material modification. Use of these genetic profiles will aid in the pursuit of improved device biocompatibility and enhanced material function.
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Affiliation(s)
- Mark A Schwartz
- Biomedical Engineering Program, University of Arizona, Tucson, Arizona 85724, USA
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Gauvreau V, Chevallier P, Vallières K, Petitclerc E, Gaudreault RC, Laroche G. Engineering Surfaces for Bioconjugation: Developing Strategies and Quantifying the Extent of the Reactions. Bioconjug Chem 2004; 15:1146-56. [PMID: 15366971 DOI: 10.1021/bc049858u] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This study presents two-step and multistep reactions for modifying the surface of plasma-functionalized poly(tetrafluoroethylene) (PTFE) surfaces for subsequent conjugation of biologically relevant molecules. First, PTFE films were treated by a radiofrequency glow discharge (RFGD) ammonia plasma to introduce amino groups on the fluoropolymer surface. This plasma treatment is well optimized and allows the incorporation of a relative surface concentration of approximately 2-3.5% of amino groups, as assessed by chemical derivatization followed by X-ray photoelectron spectroscopy (XPS). In a second step, these amino groups were further reacted with various chemical reagents to provide the surface with chemical functionalities such as maleimides, carboxylic acids, acetals, aldehydes, and thiols, that could be used later on to conjugate a wide variety of biologically relevant molecules such as proteins, DNA, drugs, etc. In the present study, glutaric and cis-aconitic anhydrides were evaluated for their capability to provide carboxylic functions to the PTFE plasma-treated surface. Bromoacetaldehyde diethylacetal was reacted with the aminated PTFE surface, providing a diethylacetal function, which is a latent form of aldehyde functionality. Reactions with cross-linkers such as sulfo-succinimidyl derivatives (sulfo-SMCC, sulfo-SMPB) were evaluated to provide a highly reactive maleimide function suitable for further chemical reactions with thiolated molecules. Traut reagent (2-iminothiolane) was also conjugated to introduce a thiol group onto the fluoropolymer surface. PTFE-modified surfaces were analyzed by XPS with a particular attention to quantify the extent of the reactions that occurred on the polymer. Finally, surface immobilization of fibronectin performed using either glutaric anhydride or sulfo-SMPB activators demonstrated the importance of selecting the appropriate conjugation strategy to retain the protein biological activity.
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Affiliation(s)
- Virginie Gauvreau
- Unité de Biotechnologie et de Bioingénierie, Centre de Recherche de l'Hôpital Saint-François d'Assise, C.H.U.Q., 10 rue de l'Espinay, Québec, Québec, Canada, G1L 3L5
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Abstract
Within native tissues cells are held within the extracellular matrix (ECM), which has a role in maintaining homeostasis, guiding development and directing regeneration. Efforts in tissue engineering have aimed to mimick the ECM to help guide morphogenesis and tissue repair. Studies have not only looked at ways to mimick the structure and characteristics of the ECM, but have also considered ways to reproduce its molecular properties including its bioadhesive character, proteolytic susceptibility and ability to bind growth factors.
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Affiliation(s)
- Jeffrey A Hubbell
- Institute for Biological and Chemical Engineering, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Ecublens, Switzerland.
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Kidd KR, Williams SK. Laminin-5-enriched extracellular matrix accelerates angiogenesis and neovascularization in association with ePTFE. J Biomed Mater Res A 2004; 69:294-304. [PMID: 15058002 DOI: 10.1002/jbm.a.20133] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The performance of biomedical implant devices is often limited by inappropriate tissue responses associated with synthetic materials used in device construction. Adverse healing responses, in particular the lack of an extensive vascular supply in the peri-implant tissue, are believed to lead to the ultimate failure of many of these medical devices. Accelerated formation of new blood vessels in the peri-implant tissue and within porous polymeric implants is hypothesized to improve the performance of such biomedical implant devices. The current study evaluated the use of cell-mediated, extracellular matrix modification of expanded polytetrafluoroethylene (ePTFE) to increase vessel growth in peri-implant tissue and within the pores of the implants. Discs of ePTFE were modified through cell-mediated matrix deposition using epithelial and endothelial cell lines with variable deposition of collagen types, fibronectin, and laminin types. Cell matrix-modified discs, Matrigel-coated discs, and nonmodified discs were implanted in both the adipose and subcutaneous tissues of the rat. Following a 5-week implant period, samples were removed and evaluated histologically and morphometrically for the presence of blood vessels in the peri-implant tissue and within the pores of the polymer as well as for the presence of activated macrophages and monocytes. A significantly increased presence of activated macrophages and monocytes was associated only with the samples modified with the matrix from a human microvessel endothelial cell line. Increased vessel density was identified in association with those ePTFE samples modified with either the 804-G, HaCaT, or II-4 cell matrices, all of which have extracellular matrices enriched in the protein laminin-5.
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Affiliation(s)
- Kameha R Kidd
- Biomedical Engineering Program, University of Arizona, Tucson, Arizona 85724, USA
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Crombez M, Mantovani D. Progresses in synthetic vascular prostheses: toward the endothelialization. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2004; 534:165-77. [PMID: 12903719 DOI: 10.1007/978-1-4615-0063-6_13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Affiliation(s)
- Mathilde Crombez
- Bioengineering and Biotechnology Unit, St-François d'Assise Hospital Research Centre and Laval University, Department of Materials Engineering, Laboratory for Biomaterials and Bioengineering, Quebec City, G1K 7P4, Canada
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Gumpenberger T, Heitz J, Bäuerle D, Kahr H, Graz I, Romanin C, Svorcik V, Leisch F. Adhesion and proliferation of human endothelial cells on photochemically modified polytetrafluoroethylene. Biomaterials 2003; 24:5139-44. [PMID: 14568430 DOI: 10.1016/s0142-9612(03)00460-5] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We studied the adhesion and proliferation of human endothelial cells on photochemically modified polytetrafluoroethylene samples. The polymer surfaces were modified by exposure to the ultraviolet light of a Xe(2)(*)-excimer lamp at a wavelength of 172 nm in an ammonia atmosphere. Treatment times were between 10 and 20 min. The endothelial cell density was determined 1, 3 and 8 days after seeding by image analysis. Surface modification of the samples resulted in a significant increase in the number of adhering cells and in the formation of a confluent cell layer after 3-8 days. The results were comparable than those obtained on polystyrene Petri dishes, which are used as standard substrates in cell cultivation. Thus modified PTFE appears to be a promising material for the fabrication of artificial vascular prostheses coated with endothelial cells.
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Affiliation(s)
- T Gumpenberger
- Department of Applied Physics, Johannes Kepler University, Linz A-4040, Austria
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Heitz J, Svorcík V, Bacáková L, Rocková K, Ratajová E, Gumpenberger T, Bäuerle D, Dvoránková B, Kahr H, Graz I, Romanin C. Cell adhesion on polytetrafluoroethylene modified by UV-irradiation in an ammonia atmosphere. J Biomed Mater Res A 2003; 67:130-7. [PMID: 14517870 DOI: 10.1002/jbm.a.10043] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We report on the modification of polytetrafluoroethylene (PTFE) by exposure to the ultraviolet (UV) light of a Xe(2)*-excimer lamp at a wavelength of 172 nm in an ammonia atmosphere. Typical treatment times were up to 30 min. Subsequently, the samples were grafted with the amino acid alanine from an aqueous solution. The samples were characterized by means of optical transmission spectroscopy, laser-induced fluorescence and contact-angle measurements. We studied the adhesion of rat aortic smooth muscle cells (SMC) and mouse fibroblasts (3T3 cells) to the modified polymer samples using an in vitro technique, where the population density and spread of adhering cells is determined 24 h after seeding by image analysis. For both cell types the exposure of PTFE to UV-light in an ammonia atmosphere resulted in a significant increase in the number of adhering cells and in the size of their spreading area. The grafting with alanine enhanced this effect. Additional experiments with human endothelial cells (HEC) also demonstrated improved adhesion to modified PTFE. Thus, PTFE modified by our method appears to be a promising material for fabrication of artificial vascular prostheses and implants or for cultivation of skin substitutes.
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Affiliation(s)
- J Heitz
- Angewandte Physik, Johannes Kepler Universität, A-4040 Linz, Austria.
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Erzurum VZ, Bian JF, Husak VA, Ellinger J, Xue L, Burgess WH, Greisler HP. R136K fibroblast growth factor-1 mutant induces heparin-independent migration of endothelial cells through fibrin glue. J Vasc Surg 2003; 37:1075-81. [PMID: 12756357 DOI: 10.1067/mva.2003.177] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES R136K is a mutation of fibroblast growth factor-1 (FGF-1) in which arginine replaces lysine at the primary thrombin cleavage site. This may be important in vivo in inducing endothelial cell (EC) migration and coverage of arterial injury sites by allowing R136K to be used in a fibrin glue delivery system, without thrombin-induced degradation, in the absence of heparin. The objectives of this study were to determine whether R136K, with and without heparin, can induce migration of EC and smooth muscle cells (SMC) through fibrin glue, and to compare these results with those of wild-type FGF-1; and to determine the resistance of R136K to thrombin-induced degradation versus FGF-1. METHODS The dose-response migration through fibrin glue induced by wild-type FGF-1 and the R136K mutant in the presence and absence of heparin was tested with EC and SMC. Migration was tested with 50, 100, and 200 ng/mL of both FGF-1 and R136K, either with or without 5 U/mL of heparin. Migration of EC was also assessed after growth inhibition with mitomycin C. A novel modified Boyden chamber-type migration assay using fibrin glue on the upper surface of the chamber filter was used to test migration. The fluorescent marker calcein was used to identify those cells that had migrated through the fibrin glue and were embedded in the filter. Molecular degradation by thrombin was assessed with sodium dodecylsulfate polyacrylamide gel electrophoresis. RESULTS For EC, R136K in the absence of heparin induced significantly more migration than did FGF-1 at 50 (P <.002), 100 (P <.0001), and 200 (P <.0001) ng/mL. In the presence of heparin, a chemotactic response of EC to cytokine was seen at all doses, with no significant difference between FGF-1 and R136K. A dose-dependent difference was noted in this group between the 100 and 200 ng/mL concentrations of cytokine (for FGF-1, P <.0001; for R136K, P <.0001). SMC showed no difference in migration with FGF-1, R136K, or negative control at any dose in the presence or absence of heparin. Gel electrophoresis demonstrated that R136K was more resistant to thrombin degradation than was FGF-1. CONCLUSION Site-directed mutagenesis of FGF-1 to R136K enables induction of heparin-independent migration of EC through fibrin glue at an optimal concentration of 100 ng/mL. Neither FGF-1 nor R136K elicits SMC migration through fibrin glue. The ability of R136K to induce EC migration through fibrin glue in the absence of heparin may prove useful in vivo by inducing EC migration and coverage of arterial injury sites, thus potentially reducing thrombogenicity and intimal hyperplasia.
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Perego G, Preda P, Pasquinelli G, Curti T, Freyrie A, Cenni E. Functionalization of poly-L-lactic-co-ε-caprolactone: effects of surface modification on endothelial cell proliferation and hemocompatibility. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2003; 14:1057-75. [PMID: 14661879 DOI: 10.1163/156856203769231565] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A copolymer of L-lactic acid and epsilon-caprolactone (PLLACL) was synthesized with the aim of preparing a bioartificial, small-diameter and partially resorbable vascular graft. The material was submitted to surface functionalizations (i.e. chemical modification by means of hydrolytic 'etching' and plasma discharge) to promote endothelial cell (EC) adhesion and growth avoiding platelet adhesion or coagulation factor absorption. Furthermore, the behaviour of human microvascular endothelial cells (HMVEC) seeded on the untreated and treated copolymer is described, as well as the platelet adhesion and the modifications of coagulation factors determined by the copolymer itself. PLLACL in its native state provided little support for EC adhesion. Improved EC adherence was obtained when functional groups were provided on the polymer surface by surface chemical hydrolysis. HMVEC seeded and cultured on the polymer surface did not show any ultrastructural alteration, thus demonstrating the absence of the polymer cytotoxicity. Moreover, SEM analysis performed on cold plasma modified specimens showed the presence of a subconfluent monolayer of EC, with an elongated spread morphology. Both the untreated and treated copolymers induced only slight variations of platelet number, but determined the activated partial thromboplastin time (APTT) increase, due to factor XI reduction. Finally, a prototype of partially biodegradable vascular prosthesis was prepared with NaOH/HCl-treated copolymer. Pre-cultured HMVEC seeding of the prosthesis by means of a rotation device resulted in an almost completely coverage of the graft inner surface.
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Affiliation(s)
- Howard P Greisler
- Loyola University Medical Center, 2160 South First Avenue, Maywood, IL 60153, USA.
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