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Deng Y, Wen Y, Yin J, Huang J, Zhang R, Zhang G, Qiu D. Corroded iron stent increases fibrin deposition and promotes endothelialization after stenting. Bioeng Transl Med 2023; 8:e10469. [PMID: 37206231 PMCID: PMC10189476 DOI: 10.1002/btm2.10469] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 11/19/2022] [Accepted: 11/30/2022] [Indexed: 12/15/2022] Open
Abstract
Poststent restenosis is caused by insufficient endothelialization and is one of the most serious clinical complications of stenting. We observed a rapid endothelialization rate and increased fibrin deposition on the surfaces of the corroded iron stents. Thus, we hypothesized that corroded iron stents would promote endothelialization by increasing fibrin deposition on rough surfaces. To verify this hypothesis, we conducted an arteriovenous shunt experiment to analyze fibrin deposition in the corroded iron stents. We implanted a corroded iron stent in both the carotid and iliac artery bifurcations to elucidate the effects of fibrin deposition on endothelialization. Co-culture experiments were conducted under dynamic flow conditions to explore the relationship between fibrin deposition and rapid endothelialization. Our findings indicate that, from the generation of corrosion pits, the surface of the corroded iron stent was rough, and numerous fibrils were deposited in the corroded iron stent. Fibrin deposition in corroded iron stents facilitates endothelial cell adhesion and proliferation, which, in turn, promotes endothelialization after stenting. Our study is the first to elucidate the role of iron stent corrosion in endothelialization, pointing to a new direction for preventing clinical complications caused by insufficient endothelialization.
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Affiliation(s)
- Yalan Deng
- NHC Key Laboratory of Cancer Proteomics & Laboratory of Structural Biology, Xiangya HospitalCentral South UniversityChangshaHunanPeople's Republic of China
| | - Yanbin Wen
- Department of Neurology, Xiangya HospitalCentral South UniversityChangshaHunanPeople's Republic of China
| | - Jun Yin
- Department of Neurology, Xiangya HospitalCentral South UniversityChangshaHunanPeople's Republic of China
| | - Jiabing Huang
- Department of CardiologyThe Second Affiliated Hospital of Nanchang UniversityNanchangJiangxiPeople's Republic of China
| | - Rongsen Zhang
- Department of Ultrasonography, Second Xiangya HospitalCentral South UniversityChangshaChina
| | - Gui Zhang
- R&D Center, Lifetech Scientific (Shenzhen) Co LtdShenzhenPeople's Republic of China
| | - Dongxu Qiu
- Department of Neurology, Xiangya HospitalCentral South UniversityChangshaHunanPeople's Republic of China
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Collagen-Sealed Polyester Vascular Prostheses Functionalized by Polycatecholamine Coatings. Int J Mol Sci 2022; 23:ijms23169369. [PMID: 36012635 PMCID: PMC9409057 DOI: 10.3390/ijms23169369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 08/11/2022] [Accepted: 08/16/2022] [Indexed: 11/19/2022] Open
Abstract
Collagen-sealed polyester (PET) prostheses are commonly used in reconstructive vascular surgery due to their self-sealing properties. To prevent post-surgical infection, different modification methods have been tested but so far none have showed long-term satisfactory efficiency. For this reason, in the present study, a commercial collagen-sealed PET prosthesis was coated by a highly adhesive poly (L-DOPA) layer maintaining the sealing protein without losing the original properties and functionality. This modified (as proven by SEM, FTIR, XPS and contact angle) graft exhibited comparable wettability and elasticity as pristine commercial graft, as well as reduced hemolysis-inducing effect, lowered toxicity against human endothelial cells and reduced toxicity in Danio rerio model. Poly (L-DOPA)-coated grafts were shown to bind six times more aminoglycoside antibiotic (gentamicin) than pristine graft. Poly (L-DOPA)-coated antibiotic-bound prostheses exhibited an improved antibacterial activity (bacterial growth inhibition and anti-adhesive capacity) in comparison with pristine antibiotic-bound graft. Overall, poly (L-DOPA)-coatings deposited on PET vascular grafts can effectively functionalize collagen-sealed prostheses without the loss of protein sealing layer and allow for antibiotics incorporation to provide higher safety in biomedical applications.
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Wolfe JT, Shradhanjali A, Tefft BJ. Strategies for improving endothelial cell adhesion to blood-contacting medical devices. TISSUE ENGINEERING PART B-REVIEWS 2021; 28:1067-1092. [PMID: 34693761 DOI: 10.1089/ten.teb.2021.0148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The endothelium is a critical mediator of homeostasis on blood-contacting surfaces in the body, serving as a selective barrier to regulate processes such as clotting, immune cell adhesion, and cellular response to fluid shear stress. Implantable cardiovascular devices including stents, vascular grafts, heart valves, and left ventricular assist devices are in direct contact with circulating blood and carry a high risk for platelet activation and thrombosis without a stable endothelial cell (EC) monolayer. Development of a healthy endothelium on the blood-contacting surface of these devices would help ameliorate risks associated with thrombus formation and eliminate the need for long-term anti-platelet or anti-coagulation therapy. Although ECs have been seeded onto or recruited to these blood-contacting surfaces, most ECs are lost upon exposure to shear stress due to circulating blood. Many investigators have attempted to generate a stable EC monolayer by improving EC adhesion using surface modifications, material coatings, nanofiber topology, and modifications to the cells. Despite some success with enhanced EC retention in vitro and in animal models, no studies to date have proven efficacious for routinely creating a stable endothelium in the clinical setting. This review summarizes past and present techniques directed at improving the adhesion of ECs to blood-contacting devices.
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Affiliation(s)
- Jayne Taylor Wolfe
- Medical College of Wisconsin, 5506, Biomedical Engineering, 8701 Watertown Plank Rd, Milwaukee, Wisconsin, United States, 53226-0509;
| | - Akankshya Shradhanjali
- Medical College of Wisconsin, 5506, Biomedical Engineering, Milwaukee, Wisconsin, United States;
| | - Brandon J Tefft
- Medical College of Wisconsin, 5506, Biomedical Engineering, Milwaukee, Wisconsin, United States;
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Spadaccio C, Nappi F, De Marco F, Sedati P, Sutherland FWH, Chello M, Trombetta M, Rainer A. Preliminary In Vivo Evaluation of a Hybrid Armored Vascular Graft Combining Electrospinning and Additive Manufacturing Techniques. Drug Target Insights 2016; 10:1-7. [PMID: 26949333 PMCID: PMC4772909 DOI: 10.4137/dti.s35202] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 11/12/2015] [Accepted: 11/16/2015] [Indexed: 11/05/2022] Open
Abstract
In this study, we tested in vivo effectiveness of a previously developed poly-l-lactide/poly-ε-caprolactone armored vascular graft releasing heparin. This bioprosthesis was designed in order to overcome the main drawbacks of tissue-engineered vascular grafts, mainly concerning poor mechanical properties, thrombogenicity, and endothelialization. The bioprosthesis was successfully implanted in an aortic vascular reconstruction model in rabbits. All grafts implanted were patent at four weeks postoperatively and have been adequately populated by endogenous cells without signs of thrombosis or structural failure and with no need of antiplatelet therapy. The results of this preliminary study might warrant for further larger controlled in vivo studies to further confirm these findings.
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Affiliation(s)
- Cristiano Spadaccio
- Department of Cardiothoracic Surgery, Golden Jubilee National Hospital, Clydebank, Dunbartonshire, UK
| | - Francesco Nappi
- Cardiac Surgery, Centre Cardiologique du Nord de Saint-Denis, Paris, France
| | - Federico De Marco
- Laboratory of Virology, The Regina Elena National Cancer Institute, Rome, Italy
| | - Pietro Sedati
- Unit of Imaging and Diagnostics, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Fraser W H Sutherland
- Department of Cardiothoracic Surgery, Golden Jubilee National Hospital, Clydebank, Dunbartonshire, UK
| | - Massimo Chello
- Unit of Cardiac Surgery, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Marcella Trombetta
- Tissue Engineering Laboratory, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Alberto Rainer
- Tissue Engineering Laboratory, Università Campus Bio-Medico di Roma, Rome, Italy
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Tefft BJ, Kopacz AM, Liu WK, Liu SQ. Enhancement of Endothelial Cell Retention on ePTFE Vascular Constructs by siRNA-Mediated SHP-1 or SHP-2 Gene Silencing. Cell Mol Bioeng 2015. [DOI: 10.1007/s12195-015-0392-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Kurane A, Vyavahare N. Endothelial cells seeded on elastin–heparin matrices express normal EC markers and resist detachment on exposure to shear stress: a histological study. J Histotechnol 2013. [DOI: 10.1179/014788811x12949268296004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Tran PL, Gamboa JR, McCracken KE, Riley MR, Slepian MJ, Yoon JY. Nanowell-trapped charged ligand-bearing nanoparticle surfaces: a novel method of enhancing flow-resistant cell adhesion. Adv Healthc Mater 2013; 2:1019-27. [PMID: 23225491 PMCID: PMC4077426 DOI: 10.1002/adhm.201200250] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 09/29/2012] [Indexed: 01/07/2023]
Abstract
Assuring cell adhesion to an underlying biomaterial surface is vital in implant device design and tissue engineering, particularly under circumstances where cells are subjected to potential detachment from overriding fluid flow. Cell-substrate adhesion is a highly regulated process involving the interplay of mechanical properties, surface topographic features, electrostatic charge, and biochemical mechanisms. At the nanoscale level, the physical properties of the underlying substrate are of particular importance in cell adhesion. Conventionally, natural, pro-adhesive, and often thrombogenic, protein biomaterials are frequently utilized to facilitate adhesion. In the present study, nanofabrication techniques are utilized to enhance the biological functionality of a synthetic polymer surface, polymethymethacrylate, with respect to cell adhesion. Specifically we examine the effect on cell adhesion of combining: 1. optimized surface texturing, 2. electrostatic charge and 3. cell adhesive ligands, uniquely assembled on the substrata surface, as an ensemble of nanoparticles trapped in nanowells. Our results reveal that the ensemble strategy leads to enhanced, more than simply additive, endothelial cell adhesion under both static and flow conditions. This strategy may be of particular utility for enhancing flow-resistant endothelialization of blood-contacting surfaces of cardiovascular devices subjected to flow-mediated shear.
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Affiliation(s)
- Phat L Tran
- Department of Biomedical Engineering, The University of Arizona, Tucson, AZ 85721, USA.
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Filová E, Brynda E, Riedel T, Chlupáč J, Vandrovcová M, Svindrych Z, Lisá V, Houska M, Pirk J, Bačáková L. Improved adhesion and differentiation of endothelial cells on surface-attached fibrin structures containing extracellular matrix proteins. J Biomed Mater Res A 2013; 102:698-712. [PMID: 23723042 DOI: 10.1002/jbm.a.34733] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 01/07/2013] [Accepted: 01/09/2013] [Indexed: 02/04/2023]
Abstract
Currently used vascular prostheses are hydrophobic and do not allow endothelial cell (EC) adhesion and growth. The aim of this study was to prepare fibrin (Fb)-based two-dimensional (2D) and three-dimensional (3D) assemblies coated with extracellular matrix (ECM) proteins and to evaluate the EC adhesion, proliferation and differentiation on these assemblies in vitro. Coating of Fb with collagen, laminin (LM), and fibronectin (FN) was proved using the surface plasmon resonance technique. On all Fb assemblies, ECs reached higher cell densities than on polystyrene after 3 and 7 days of culture. Immunoflurescence staining showed better assembly of talin and vinculin into focal adhesion plaques, and also more apparent staining of vascular endothelial cadherin on surface-attached 3D Fb and protein-coated Fb assemblies. On these samples, ECs also contained a lower concentration of intercellular adhesion molecule-1, measured by enzyme-linked immunosorbent assay. Higher concentrations of CD31 (platelet-endothelial cell adhesion molecule-1) were found on 3D Fb coated with LM, and higher concentrations of von Willebrand factor were found on 3D Fb coated with type I collagen or LM in comparison to 2D Fb layers. The results indicate that ECM protein-coated 2D and 3D Fb assemblies can be used for versatile applications in various tissue replacements where endothelialization is desirable, for example, vascular prostheses and heart valves.
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Affiliation(s)
- Elena Filová
- Department of Biomaterials and Tissue Engineering, Institute of Physiology, Academy of Sciences of the Czech Republic, v.v.i., 142 20 Prague 4, Czech Republic
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Tefft BJ, Kopacz AM, Liu WK, Liu SQ. Enhancing Endothelial Cell Retention on ePTFE Constructs by siRNA-Mediated SHP-1 Gene Silencing. J Nanotechnol Eng Med 2011. [DOI: 10.1115/1.4003273] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Polymeric vascular grafts hold great promise for vascular reconstruction, but the lack of endothelial cells renders these grafts susceptible to intimal hyperplasia and restenosis, precluding widespread clinical applications. The purpose of this study is to establish a stable endothelium on expanded polytetrafluoroethylene (ePTFE) membrane by small interfering RNA (siRNA)-induced suppression of the cell adhesion inhibitor SH2 domain-containing protein tyrosine phosphatase-1 (SHP-1). Human umbilical vein endothelial cells (HUVECs) were treated with scrambled siRNA as a control or SHP-1 specific siRNA. Treated cells were seeded onto fibronectin-coated ePTFE scaffolds and exposed to a physiological range of pulsatile fluid shear stresses for 1 h in a variable-width parallel plate flow chamber. Retention of cells was measured and compared between various shear stress levels and between groups treated with scrambled siRNA and SHP-1 specific siRNA. HUVECs seeded on ePTFE membrane exhibited shear stress-dependent retention. Exposure to physiological shear stress (10 dyn/cm2) induced a reduction in the retention of scrambled siRNA treated cells from 100% to 85% at 1 h. Increased shear stress (20 dyn/cm2) further reduced retention of scrambled siRNA treated cells to 55% at 1 h. SHP-1 knockdown mediated by siRNA enhanced endothelial cell retention from approximately 60% to 85% after 1 h of exposure to average shear stresses in the range of 15–30 dyn/cm2. This study demonstrates that siRNA-mediated gene silencing may be an effective strategy for improving the retention of endothelial cells within vascular grafts.
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Affiliation(s)
- Brandon J. Tefft
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Tech E310, Evanston, IL 60208
| | - Adrian M. Kopacz
- Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Tech B224, Evanston, IL 60208
| | - Wing Kam Liu
- Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Tech B224, Evanston, IL 60208
| | - Shu Q. Liu
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Tech E310, Evanston, IL 60208
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Klemm D, Schumann D, Kramer F, Heßler N, Hornung M, Schmauder HP, Marsch S. Nanocelluloses as Innovative Polymers in Research and Application. POLYSACCHARIDES II 2006. [DOI: 10.1007/12_097] [Citation(s) in RCA: 306] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Meinhart JG, Schense JC, Schima H, Gorlitzer M, Hubbell JA, Deutsch M, Zilla P. Enhanced Endothelial Cell Retention on Shear-Stressed Synthetic Vascular Grafts Precoated with RGD-Cross-Linked Fibrin. ACTA ACUST UNITED AC 2005; 11:887-95. [PMID: 15998228 DOI: 10.1089/ten.2005.11.887] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Clinical in vitro endothelialization has been shown to increase the patency of synthetic vascular grafts. The shear stress resistance of the cultured autologous endothelium represents a crucial cornerstone of the concept. We investigated whether an enrichment of the precoating matrix with adhesion sites can augment endothelial cell attachment. Adult human saphenous vein endothelial cells (AHSVECs) were seeded confluently ([58 +/- 11] x 10(3) AHSVECs/cm2) onto 10-cm-long ePTFE (expanded polytetrafluorethylene) vascular grafts (n = 24) precoated with commercial clinically approved fibrin gel (Tisseal) containing various concentrations of cross-linked RGD peptide (0.0, 4.0, 8.0, or 16.0 mg of RGD per milliliter of Tisseal fibrinogen component). Endothelialized grafts were postcultivated for 9 days before they were exposed to a pulsatile circulation model mimicking peak physiological shear stress conditions of the femoral artery (12 dyn/cm2; min/max, -60/+28 dyn/cm2). Cell loss after 24 h was quantitatively determined by image analysis of vital stains. Initial 24-h cell loss was 27.2 +/- 1.7% in grafts precoated with the non-RGD-enriched fibrin matrix. In contrast, cell loss was significantly less on fibrin containing 4.0 mg of RGD peptide per milliliter of Tisseal fibrinogen component (13.3 +/- 7.9%; p < 0.05). Cell loss on fibrin containing 8 and 16 mg of RGD per milliliter of Tisseal fibrinogen component was 41.0 +/- 27.4 and 43.0 +/- 23.2% (p > 0.05), respectively. We conclude that low concentrations of RGD peptide cross-linked into commercial fibrin matrices used for clinical in vitro lining of vascular grafts led to significantly increased endothelial cell retention. The failure of higher RGD concentrations to enhance endothelial cell attachment may be explained by competitive binding of endothelial cells to non-cross-linked RGD.
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Chan BP, Liu W, Klitzman B, Reichert WM, Truskey GA. In vivo performance of dual ligand augmented endothelialized expanded polytetrafluoroethylene vascular grafts. ACTA ACUST UNITED AC 2004; 72:52-63. [PMID: 15389501 DOI: 10.1002/jbm.b.30114] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In this study, we examined combinations of three approaches to improve the adhesion of endothelial cells (EC) onto expanded polytetrafluoroethylene (ePTFE) vascular grafts placed at the femoral artery of rats: (1) high-affinity receptor-ligand binding of RGD-streptavidin (SA) and biotin to supplement integrin-mediated EC adhesion; (2) cell sodding to pressurize the seeded EC into the interstices of the ePTFE grafts; and (3) longer postseeding attachment time from 1 to 24 h prior to implantation. An in vitro system, which accounts for cell loss due to both graft handling and shear stress, was designed to optimize conditions for in vivo experiments. Results suggest that longer in vitro attachment time enabled the adherent EC to endure mechanical stresses by forming strong adhesions to the underlying extracellular matrix substrates; cell sodding helped to retain the adherent EC by physically docking the cells against the graft interstices; and the SA-biotin interaction enhanced the early attachment of EC but did not lead to better cell retention or reduced surface coverage of blood clot in the current study. Mechanical manipulation of cells during implantation is a limiting factor in maintaining a confluent EC layer on synthetic vascular grafts.
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Affiliation(s)
- Bernard P Chan
- Department of Biomedical Engineering, Duke University, Hudson Hall, Room 136, Box 90281, Durham, North Carolina 27708-0281, USA
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Kader KN, Sweany JM, Bellamkonda RV. Cationic lipid-mediated transfection of bovine aortic endothelial cells inhibits their attachment. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2002; 60:405-10. [PMID: 11920664 DOI: 10.1002/jbm.10062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The need for a small-diameter vascular graft for coronary artery and peripheral vascular replacement is great and is projected to increase as the population ages. Synthetic small-diameter vascular grafts fail because of acute thrombosis or chronic intimal hyperplasia leading to restenosis. Endothelial cell seeding has been attempted with limited success in the femoral artery by Zilla and others. However, patency rates have not increased sufficiently to justify large clinical trials. Genetic engineering of endothelial cells before seeding has been proposed to encourage endothelial cell phenotypes that would predispose the graft to patency. In this study, we investigate the effect cationic lipid-mediated transfection of endothelial cells with respect to their attachment to a potential graft material, Fluoropassiv (Vascutek). Liposomal transfection was optimized for maximum gene expression. We report that transfection decreases the ability of bovine aortic endothelial cells to attach by approximately 100% as compared with nontransfected control over 18 h. Further, when placed under physiologic shear conditions, this difference is sustained. The effects of gene transfer on endothelial cell adhesion must be included as an important optimization criterion along with gene expression for engineered endothelial cell-seeding applications.
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Affiliation(s)
- Khalid N Kader
- Biomaterials, Cell, and Tissue Engineering Laboratory, Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106-7207, USA
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Salacinski HJ, Tiwari A, Hamilton G, Seifalian AM. Cellular engineering of vascular bypass grafts: role of chemical coatings for enhancing endothelial cell attachment. Med Biol Eng Comput 2001; 39:609-18. [PMID: 11804165 DOI: 10.1007/bf02345431] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Surgical treatment of vascular disease has become common. The use of synthetic materials is limited to grafts larger than 5-6mm, because of the frequency of occlusion observed with small-diameter prosthetics. An alternative would be a hybrid or tissue-engineered graft with the surface coated with a monolayer of the patient's own cells. Currently, to be effective, high-density seeding regimens have to be undertaken. This is because endothelial cells (ECs) are washed off the graft lumen once exposed to physiological blood flow. EC attachment has been shown to be significantly improved by pre-coating with substances known to attach ECs selectively. The review examines the various types of coating and bonding technology used to date to enhance endothelial cell attachment onto the surface of prosthetic vascular bypass grafts.
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Affiliation(s)
- H J Salacinski
- Tissue Engineering Centre, University Department of Surgery, Royal Free and University College Medical School, University College London & Royal Free Hospital, UK
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Fernandez P, Bareille R, Conrad V, Midy D, Bordenave L. Evaluation of an in vitro endothelialized vascular graft under pulsatile shear stress with a novel radiolabeling procedure. Biomaterials 2001; 22:649-58. [PMID: 11246958 DOI: 10.1016/s0142-9612(00)00227-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To improve the hemocompatibility of vascular grafts, endothelial cell (EC) seeding of biomaterials prior to implantation is critical. The current in vitro study was designed to investigate such a feasibility on a collagen-coated heparin-bonded graft and to evaluate cell detachment upon pulsatile shear stress. MATERIALS AND METHODS Endothelial cells (EA-hy-926) were seeded onto grafts. The endothelialization of the grafts was evaluated by the [3H]-thymidine incorporation, scanning electron microscopy (SEM) and histological examinations. After in situ EC radiolabeling with a novel 99mTc technique, the prostheses were exposed to pulsatile shear stress (0.27 N/m2), mimicking the shear rate occurring in a superficial femoral artery, for 3 h in a flow circuit and EC loss quantified by gamma camera detection. RESULTS Complete EC coverage was achieved after 5 days. Three hours of artificial perfusion resulted in a low EC loss (12.9+/-0.8%, n = 7). SEM shows EC withstanding shear stress in valleys of prosthesis circumvolutions. CONCLUSIONS These satisfactory results could be explained by the high affinity of EC for heparinized surfaces in addition to cell surface receptors involved in adhesion to collagen.
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Affiliation(s)
- P Fernandez
- Laboratoire de Biophysique, Université Victor Ségalen Bordeaux 2, France.
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Salacinski HJ, Tai NR, Punshon G, Giudiceandrea A, Hamilton G, Seifalian AM. Optimal endothelialisation of a new compliant poly(carbonate-urea)urethane vascular graft with effect of physiological shear stress. Eur J Vasc Endovasc Surg 2000; 20:342-52. [PMID: 11035966 DOI: 10.1053/ejvs.2000.1185] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE to define the optimal seeding conditions of a new stress free poly(carbonate-urea)urethane (CPU) graft with compliance similar to that of human artery with honeycomb structure engineered during the manufacturing process to enhance adhesion and growth of endothelial cells. METHODS (111)Indium-oxine radiolabeled human umbilical vein endothelial cells (HUVEC) were seeded onto CPU grafts at (a) concentrations from 2-24x10(5)cells/cm(2)and (b) incubated for 0.5, 1, 2, 4 and 6 h. Following incubation, graft segments were subjected to three washing/gamma counting procedures and scanning electron microscopy (SEM). Cell viability was measured using a modified Alamar blue(TM)assay. To test physiological retention a pulsatile flow phantom was used to subject optimally seeded (16x10(5), 4 h) CPU grafts to arterial shear stress for 6 h with real time acquisition of scintigraphic images of seeded grafts using a nuclear medicine gamma camera system. RESULTS the seeding efficiency of 54+/-13% post three washes was achieved using 16x10(5)cells/cm(2). Similarly in SEM micrographs a seeding density of 16x10(5)cells/cm(2)resulted in a confluent monolayer. Seeded CPU segments incubated for 4 h exhibited significantly higher resistance to wash-off than segments incubated for 30 min (p <0.05). Exposure of seeded grafts to pulsatile shear stress resulted in some cell loss with 67+/-3% of cells adherent following 6 h of perfusion with ongoing metabolic activity. Thus, optimal conditions were 16x10(5)cells/cm(2)at 4 h. CONCLUSIONS the optimal seeding conditions have been defined for "tissue-engineered" vascular graft which allow complete endothelialisation and high cell-to-substrate strength that resists hydrodynamic stress.
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Affiliation(s)
- H J Salacinski
- Vascular Haemodynamic Laboratory, University Department of Surgery, London, NW3 2QG, UK
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Bordenave L, Remy-Zolghadri M, Fernandez P, Bareille R, Chaudet B, Baquey C. Conduite in vitro d'une étude de biocompatibilité pour la confection d'un substitut vasculaire bioartificiel de petit calibre. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s1297-9562(00)90005-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
Obstructive atherosclerotic vascular disease stands as one of the greatest public health threats in the world. While a number of therapies have been developed to combat vascular disease, endothelial cell delivery has emerged as a distinct therapeutic modality. In this article, we will review the anatomy of the normal blood vessel and the biology of the intact endothelium, focusing upon its centrality in vascular biology and control over the components of the vascular response to injury so as to understand better the motivation for a cell-based form of therapy. Our discussion of cell delivery for cardiovascular therapy will be divided into surgical and interventional approaches. We will briefly recount the development of artificial grafts for surgical vascular bypass before turning our attention towards endothelial cell seeded vascular grafts, in which endothelial cells effectively provide local delivery of endogenous endothelial secretory products to maintain prosthetic integrity after surgical implantation. New techniques in tissue and genetic engineering of vascular grafts and whole blood vessels will be presented. Methods for percutaneous interventions will be examined as well. We will evaluate results of endoluminal endothelial cell seeding for treatment of restenosis and gene therapy approaches to enhance endogenous re-endothelialization. Finally, we will examine some innovations in endothelial cell delivery that may lead to the development of endothelial cell implants as a novel therapy for controlling proliferative vascular arteriopathy.
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Affiliation(s)
- S A Parikh
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Fastenau DR, Labarrere CA, Hormuth DA, McIntyre JA. Immunohistochemical analysis of vascular prostheses implanted with the left ventricular assist system. J Heart Lung Transplant 1999; 18:916-20. [PMID: 10528755 DOI: 10.1016/s1053-2498(99)00003-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022] Open
Abstract
BACKGROUND Dacron vascular prostheses are associated with thromboembolic complications and inflammatory responses; impregnation with bovine collagen reportedly stimulates additional inflammatory/immunologic complications. The Novacor (Baxter Healthcare Corp., Oakland, CA, USA) left ventricular assist system uses Dacron inflow and collagen-impregnated Dacron outflow prostheses. METHODS Explanted inflow and outflow prostheses were evaluated for inflammatory/immunologic, hemostatic, anticoagulant, and fibrinolytic pathways. Non-implanted prostheses immersed in whole blood or plasma were used as controls. RESULTS Immunoglobulins and complement components were observed in all prostheses with activated macrophages being present only in implanted prostheses. Antithrombin III was observed in all prostheses whereas fibrin, tissue plasminogen activator, and alpha-2 plasmin inhibitor were present only in implanted prostheses. Endothelial and smooth muscle cells associated with vascular structures containing collagen type IV and laminin were observed solely in implanted prostheses. CONCLUSION An inflammatory response occurs and key components of hemostatic, anticoagulant, and fibrinolytic pathways are present within implanted prostheses. These processes are accompanied by endothelial and smooth muscle cell infiltration which appear to lay the foundation for neovessel development.
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Affiliation(s)
- D R Fastenau
- Methodist Hospital of Indiana, Indianapolis 46202, USA
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Pollara P, Alessandri G, Bonardelli S, Simonini A, Cabibbo E, Portolani N, Tiberio GA, Giulini SM, Turano A. Complete in vitro prosthesis endothelialization induced by artificial extracellular matrix. J INVEST SURG 1999; 12:81-8. [PMID: 10327077 DOI: 10.1080/089419399272638] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
This report presents our research on the conditions necessary to substain optimal in vitro prosthetic endothelialization using human endothelium cultures. Human vein endothelial cells were seeded at a concentration of 3 x 10(5)/cm2 in a gelatinized Dacron patch graft coated with a commercial collagen film, using a solution of fibrin glue. Endothelium adhesion, proliferation, and survival were measured by [3H]thymidine incorporation, after 7 days of incubation. Finally, the morphology of prosthetic endothelialization was analyzed by scanning electron microscopy. We observed that the Dacron patch grafts coated with collagen film were able to promote endothelialization better than the prostheses coated with highly concentrated collagen solution or gelatin. We therefore concluded that the collagen film that supports endothelial cell adhesion and proliferation uniformly covers the entire synthetic endoluminal surface of the Dacron graft, thus preventing endothelial cell alterations induced by direct contact with the synthetic prosthetic surface.
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Affiliation(s)
- P Pollara
- Institute of Microbiology, University of Brescia, Italy
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Abstract
In the field of cardiovascular surgery there is presently a lack of biomaterials possessing essential characteristics of the native tissue or organ which is to be replaced. This paper describes various biomaterials that have been introduced into the circulatory system and the complex reactions that subsequently occur. The risk of infection is also discussed as well as prevention and treatment regimes that can be used. Examples of future biomaterial development are outlined in an attempt to achieve biocompatibility.
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Affiliation(s)
- R Macnair
- Bristol Heart Institute, Bristol Royal Infirmary
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Noh I, Goodman SL, Hubbell JA. Chemical modification and photograft polymerization upon expanded poly(tetrafluoroethylene). JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 1998; 9:407-26. [PMID: 9648024 DOI: 10.1163/156856298x00532] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Poly(tetrafluoroethylene) (PTFE) films were surface-modified by employing a reaction solution of benzophenone and sodium hydride in anhydrous dimethylformamide at a temperature of 150 degrees C for 12 h. Electron spectroscopy for chemical analysis (ESCA) showed defluorination, oxygen incorporation, and extensive unsaturation within the treated PTFE surfaces. The suitably of these reduced PTFE films as substrates for graft polymerization was initially assessed via photograft polymerization of the sodium salt of styrenesulfonic acid (SS-Na), which permitted unequivocal surface analysis by the introduction of a new atom, as well as poly(ethylene glycol) monoacrylate (PEG-Ac). All photograpt polymerization was performed employing ultraviolet irradiation with 2,2-dimethoxy-2-phenylacetophenone as an initiator. Photograft polymerization of SS-Na was verified by further reduction of fluorine atomic content and the appearance of new sulfur and sodium atomic peaks on ESCA survey spectra, and that of PEG-Ac was verified by further reduction of fluorine atomic content and increase of atomic percent ratio of O/C from ESCA survey spectra as well as appearance of a new ester peak on high resolution ESCA C 1s spectra. Dynamic water contact angles on reduced and PEG-Ac photograft polymerized films were measured and showed that the PTFE film surface became more hydrophilic after reduction (from 120 to 89 deg) and the reduced film became more hydrophilic after photograft polymerization with PEG-Ac (from 89 to 36 deg). Modification of the complete surface of expanded PTFE (ePTFE), i.e. of the lumenal, outside and pore surfaces, was performed by employing the reaction described above, except at 105 degrees C for 1 day, followed by photograft polymerization of PEG-Ac. ESCA was performed on the superficial surfaces (i.e. the lumen and exterior) as well as on cross-sections of the ePTFE to permit analysis of the pore surfaces. This analysis showed that both the initial surface reduction and subsequent photograft polymerization were successful as indicated from F/C and O/C atomic percent ratios from ESCA survey spectra, from overall peaks shapes of high resolution ESCA C 1s spectra and from generation of new ester peaks on high resolution ESCA C 1s spectra of ePTFE graft polymerized with PEG-Ac, which demonstrated an O/C atomic percent ratio close to that of PEG-Ac homopolymer. Low voltage scanning electron microscopy confirmed minimal morphological damage to the ePTFE microstructure after reduction and graft polymerization. The approach explored thus provides a means for modulation of biological interactions at ePTFE surfaces with only minimal modification of material morphology, with some surface texture appearing on a length scale of 50-100 nm.
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Affiliation(s)
- I Noh
- Department of Chemical Engineering, University of Texas, Austin 78712, USA
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