Tissue-engineered vascular grafts and regeneration mechanisms

Author(s):  
Yongzhen Wei ◽  
Fei Wang ◽  
Zhikun Guo ◽  
Zhao Qiang
Keyword(s):  
Author(s):  
E.J. Prendiville ◽  
S. Laliberté Verdon ◽  
K. E. Gould ◽  
K. Ramberg ◽  
R. J. Connolly ◽  
...  

Endothelial cell (EC) seeding is postulated as a mechanism of improving patency in small caliber vascular grafts. However the majority of seeded EC are lost within 24 hours of restoration of blood flow in previous canine studies . We postulate that the cells have insufficient time to fully develop their attachment to the graft surface prior to exposure to hemodynamic stress. We allowed EC to incubate on fibronectin-coated ePTFE grafts for four different time periods after seeding and measured EC retention after perfusion in a canine ex vivo shunt circuit.Autologous canine EC, were enzymatically harvested, grown to confluence, and labeled with 30 μCi 111 Indium-oxine/80 cm 2 flask. Four groups of 5 cm x 4 mm ID ePTFE vascular prostheses were coated with 1.5 μg/cm.2 human fibronectin, and seeded with 1.5 x 105 EC/ cm.2. After seeding grafts in Group 1 were incubated in complete growth medium for 90 minutes, Group 2 were incubated for 24 hours, Group 3 for 72 hours and Group 4 for 6 days. Grafts were then placed in the canine ex vivo circuit, constructed between femoral artery and vein, and subjected to blood flow of 75 ml per minute for 6 hours. Continuous counting of γ-activity was made possible by placing the seeded graft inside the γ-counter detection crystal for the duration of perfusion. EC retention data after 30 minutes, 2 hours and 6 hours of flow are shown in the table.


1994 ◽  
Vol 27 (1) ◽  
pp. 91-123 ◽  
Author(s):  
Roy M. Fujitani ◽  
David L. Cull ◽  
David L. Dawson

1985 ◽  
Vol 53 (03) ◽  
pp. 423-427 ◽  
Author(s):  
Stephen R Hanson ◽  
Laurence A Harker

SummarySuloctidil has been evaluated in the baboon for its antithrombotic efficacy using models of both acute and chronic arterial thrombogenesis. Acute thrombus formation was initiated by Dacron vascular grafts inserted as extension segments into chronic arteriovenous shunts. 111In-platelet deposition was measured by scintillation camera imaging for one hour. The results after oral administration of suloctidil (100 mg/kg/d in two divided doses) were not different from control studies. Moreover, concurrent heparin anticoagulation did not affect 111In-platelet deposition compared with control data. In contrast, ticlopidine (20 mg/ kg/d) significantly decreased platelet deposition that was reduced further by the addition of heparin.Chronic arterial-thromboembolism was initiated by segments of polyurethane (Biomer) cannula introduced into chronic arteriovenous shunts. Thrombus formation by the polyurethane cannula was measured as 111In-platelet turnover (corrected for removal of senescent platelets). Cannula platelet consumption was unaffected by suloctidil (20 mg/kg/d given in two divided doses for two days preceding and throughout the period of platelet survival measurement). In contrast, dipyridamole (10 mg/ kg/d) and sulfinpyrazone (100 mg/kg/d) completely interrupted cannula platelet consumption.We conclude that suloctidil probably has little or no effect on platelet-dependent thrombus formation.


2007 ◽  
Vol 55 (S 1) ◽  
Author(s):  
CD Etz ◽  
TM Homann ◽  
D Silovitz ◽  
M Lühr ◽  
CA Bodian ◽  
...  

2020 ◽  
Vol 27 (10) ◽  
pp. 1634-1646 ◽  
Author(s):  
Huey-Shan Hung ◽  
Shan-hui Hsu

Treatment of cardiovascular disease has achieved great success using artificial implants, particularly synthetic-polymer made grafts. However, thrombus formation and restenosis are the current clinical problems need to be conquered. New biomaterials, modifying the surface of synthetic vascular grafts, have been created to improve long-term patency for the better hemocompatibility. The vascular biomaterials can be fabricated from synthetic or natural polymers for vascular tissue engineering. Stem cells can be seeded by different techniques into tissue-engineered vascular grafts in vitro and implanted in vivo to repair the vascular tissues. To overcome the thrombogenesis and promote the endothelialization effect, vascular biomaterials employing nanotopography are more bio-mimic to the native tissue made and have been engineered by various approaches such as prepared as a simple surface coating on the vascular biomaterials. It has now become an important and interesting field to find novel approaches to better endothelization of vascular biomaterials. In this article, we focus to review the techniques with better potential improving endothelization and summarize for vascular biomaterial application. This review article will enable the development of biomaterials with a high degree of originality, innovative research on novel techniques for surface fabrication for vascular biomaterials application.


Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 77
Author(s):  
Enric Casanova-Batlle ◽  
Antonio J. Guerra ◽  
Joaquim Ciurana

Bioresorbable cardiovascular applications are increasing in demand as fixed medical devices cause episodes of late restenosis. The autologous treatment is, so far, the gold standard for vascular grafts due to the similarities to the replaced tissue. Thus, the possibility of customizing each application to its end user is ideal for treating pathologies within a dynamic system that receives constant stimuli, such as the cardiovascular system. Direct Ink Writing (DIW) is increasingly utilized for biomedical purposes because it can create composite bioinks by combining polymers and materials from other domains to create DIW-printable materials that provide characteristics of interest, such as anticoagulation, mechanical resistance, or radiopacity. In addition, bioinks can be tailored to encounter the optimal rheological properties for the DIW purpose. This review delves into a novel emerging field of cardiovascular medical applications, where this technology is applied in the tubular 3D printing approach. Cardiovascular stents and vascular grafts manufactured with this new technology are reviewed. The advantages and limitations of blending inks with cells, composite materials, or drugs are highlighted. Furthermore, the printing parameters and the different possibilities of designing these medical applications have been explored.


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