6 results on '"Small diameter vascular graft"'
Search Results
2. Promoting Endothelialization of Polymeric Cardiovascular Biomaterials.
- Author
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Heath, Daniel E.
- Subjects
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BIOMATERIALS , *VASCULAR grafts , *ENDOTHELIUM , *ENDOTHELIAL cells , *MONOMOLECULAR films - Abstract
The lack of a blood compatible synthetic interface is one of the largest unaddressed challenges in the field of biomaterials science. This technological shortcoming hinders the successful clinical application of small diameter vascular grafts and other cardiovascular devices such as stents and artificial heart valves. Therefore, intensive research activities are ongoing to develop polymer materials with improved blood compatibility. One attractive strategy to improve the blood compatibility of an interface is to design surfaces that promote the development of an endothelium, the monolayer of endothelial cells that line our native vasculature and is responsible for blood compatibility. This article describes the recent strategies that have been used to generate polymeric materials that promote the development of an endothelium, discusses shortcomings in the field, and proposes future directions of research that can be undertaken to design next generation polymeric biomaterial that promote endothelialization. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
3. Computationally Optimizing the Compliance of a Biopolymer Based Tissue Engineered Vascular Graft.
- Author
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Harrison, Scott, Tamimi, Ehab, Uhlorn, Josh, Leach, Tim, and Vande Geest, Jonathan P.
- Subjects
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TISSUE engineering , *VASCULAR grafts , *BIOPROSTHESIS , *GLUTARALDEHYDE , *FIBRINOGEN , *CROSSLINKING (Polymerization) - Abstract
Coronary heart disease is a leading cause of death among Americans for which coronary artery bypass graft (CABG) surgery is a standard surgical treatment. The success of CABG surgery is impaired by a compliance mismatch between vascular grafts and native vessels. Tissue engineered vascular grafts (TEVGs) have the potential to be compliance matched and thereby reduce the risk of graft failure. Glutaraldehyde (GLUT) vapor-crosslinked gelatin/fibrinogen constructs were fabricated and mechanically tested in a previous study by our research group at 2. 8, and 24 hrs of GLUT vapor exposure. The current study details a computational method that was developed to predict the material properties of our constructs for crosslinking times between 2 and 24 hrs by interpolating the 2. 8, and 24 hrs crosslinking time data. MATLAB and ABAQUS were used to determine the optimal combination of fabrication parameters to produce a compliance matched construct. The validity of the method was tested by creating a 16-hr crosslinked construct of 130 pm thickness and comparing its compliance to that predicted by the optimization algorithm. The predicted compliance of the 16-hr construct was 0.00059 mm Hg-1 while the experimentally determined compliance was 0.00065 mm Hg-1, a relative difference of 9.2%. Prior data in our laboratory has shown the compliance of the left anterior descending porcine coronary (LADC) artery to he 0.00071 ± 0.0003 mm Hg-1. Our optimization algorithm predicts that a 258-pm-thick construct that is GLUT vapor crosslinked for 8.1 hrs would match LADC compliance. This result is consistent with our previous work demonstrating that an 8-hr GLUT vapor crosslinked construct produces a compliance that is not significantly different from a porcine coronary LADC. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
4. Biomimetic tubular scaffold with heparin conjugation for rapid degradation in in situ regeneration of a small diameter neoartery.
- Author
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Navarro, Renato S., Jiang, Longtan, Ouyang, Yang, Luo, Jiawen, Liu, Zhiyong, Yang, Ying, Qiu, Ping, Kuroda, Kenichi, Chen, Y. Eugene, Ma, Peter X., and Yang, Bo
- Subjects
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METAL scaffolding , *VASCULAR grafts , *HEPARIN , *ANIMAL disease models , *CLICK chemistry , *METHYL groups , *POLYCAPROLACTONE - Abstract
To address the clinical need for readily available small diameter vascular grafts, biomimetic tubular scaffolds were developed for rapid in situ blood vessel regeneration. The tubular scaffolds were designed to have an inner layer that is porous, interconnected, and with a nanofibrous architecture, which provided an excellent microenvironment for host cell invasion and proliferation. Through the synthesis of poly(spirolactic-co-lactic acid) (PSLA), a highly functional polymer with a norbornene substituting a methyl group in poly(l -lactic acid) (PLLA), we were able to covalently attach biomolecules onto the polymer backbone via thiol-ene click chemistry to impart desirable functionalities to the tubular scaffolds. Specifically, heparin was conjugated on the scaffolds in order to prevent thrombosis when implanted in situ. By controlling the amount of covalently attached heparin we were able to modulate the physical properties of the tubular scaffold, resulting in tunable wettability and degradation rate while retaining the porous and nanofibrous morphology. The scaffolds were successfully tested as rat abdominal aortic replacements. Patency and viability were confirmed through dynamic ultrasound and histological analysis of the regenerated tissue. The harvested tissue showed excellent vascular cellular infiltration, proliferation, and migration with laminar cellular arrangement. Furthermore, we achieved both complete reendothelialization of the vessel lumen and native-like media extracellular matrix. No signs of aneurysm or hyperplasia were observed after 3 months of vessel replacement. Taken together, we have developed an effective vascular graft able to generate small diameter blood vessels that can function in a rat model. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
5. Fucoidan functionalization on poly(vinyl alcohol) hydrogels for improved endothelialization and hemocompatibility.
- Author
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Yao, Yuan, Zaw, Aung Moe, Anderson, Deirdre E.J., Hinds, Monica T., and Yim, Evelyn K.F.
- Subjects
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POLYVINYL alcohol , *VASCULAR grafts , *CELL adhesion , *BLOOD platelet activation , *ENDOTHELIAL cells , *ALCOHOL - Abstract
The performance of clinical synthetic small diameter vascular grafts remains disappointing due to the fast occlusion caused by thrombosis and intimal hyperplasia formation. Poly(vinyl alcohol) (PVA) hydrogels have tunable mechanical properties and a low thrombogenic surface, which suggests its potential value as a small diameter vascular graft material. However, PVA does not support cell adhesion and thus requires surface modification to encourage endothelialization. This study presents a modification of PVA with fucoidan. Fucoidan is a sulfated polysaccharide with anticoagulant and antithrombotic properties, which was shown to potentially increase endothelial cell adhesion and proliferation. By mixing fucoidan with PVA and co-crosslinked by sodium trimetaphosphate (STMP), the modification was achieved without sacrificing mechanical properties. Endothelial cell adhesion and monolayer function were significantly enhanced by the fucoidan modification. In vitro and ex-vivo studies showed low platelet adhesion and activation and decreased thrombin generation with fucoidan modified PVA. The modification proved to be compatible with gamma sterilization. In vivo evaluation of fucoidan modified PVA grafts in rabbits exhibited increased patency rate, endothelialization, and reduced intimal hyperplasia formation. The fucoidan modification presented here benefited the development of PVA vascular grafts and can be adapted to other blood contacting surfaces. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
6. Macromol. Chem. Phys. 8/2017.
- Author
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Heath, Daniel E.
- Subjects
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MACROMOLECULAR synthesis , *POLYMERIC composites , *BIOMATERIALS - Abstract
Front Cover: Blood clots when it contacts foreign surfaces and can result in failure of cardiovascular biomedical devices. Endothelial cells line our native vasculature and are responsible for blood compatibility. Designing materials that foster a functional layer of endothelial cells is a promising strategy for improving their blood compatibility. In the article number 1600574 Daniel E. Heath describes recent advances in the design of polymeric biomaterials that promote endothelialization. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
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