A Technology for Anti-Thrombogenic Drug Coating of Small-Diameter Biodegradable Vascular Prostheses

Background. Preclinical tests of biodegradable small diameter vascular prostheses on a sheep model have been carried out.Aim. To assess the results of long-term patency and remodeling of biodegradable vascular prostheses based on polyhydroxybutyrate / valerate and polycaprolactone with an atrombogenic drug coating in a large laboratory animal model.Methods. We researched vascular prostheses made of polyhydroxybutyrate / valerate and polycaprolactone (PHBV/PCL) 4 mm in diameter with layer-by-layer vascular endothelial growth factor incorporated into the polymer framework, the main fibroblast growth factor, chemoattractant molecule containing SDF-1a (GFmix) surface, and additional modifying drug surface heparin and iloprost (PHBV/PCL/ GFmix/Heparin/Iloprost). Animals with implanted synthetic Gore-Tex vascular grafts with a diameter of 4 mm were included into a comparison group.Results. After one day of implantation it was revealed that the patency of biodegradable PHBV/PCL/GFmix/Heparin/Iloprost prostheses was 62.5%, while synthetic Gore-Tex prostheses were thrombosed in 100% of cases. At the same time, after 18 months of implantation, the patency of biodegradable vascular PHBV/PCL/ GFmix/Heparin/Iloprost prostheses decreased to 50%. Passable drug-eluting polymer grafts were completely resorbed after 18 months of implantation, and aneurysmically expanded newly formed vascular tissue was formed in their place.Conclusion. Vascular prostheses made of polyhydroxybutyrate/valerate and polycaprolactone showed better long-term patency results than synthetic prostheses used in the clinical practice. However, the strengthening of the external framework of the prostheses is required in order to prevent the formation of aneurysms.

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Mechanical Issues in Vascular Grafting: A Review

The International Journal of Artificial Organs ◽

10.1177/039139889201501002 ◽

1992 ◽

Vol 15 (10) ◽

pp. 579-584 ◽

Cited By ~ 21

Author(s):

L.J. Brossollet

Keyword(s):

Saphenous Vein ◽

Vein Graft ◽

Vascular Grafts ◽

Small Diameter ◽

Vascular Prostheses ◽

Intensive Research ◽

Vascular Grafting ◽

Relevant Property ◽

Small Diameter Vascular Grafts

Despite intensive research, the success of artificial small-diameter vascular grafts has yet to match that of natural grafts like the saphenous vein. One of the possible reasons is mechanical mismatch of the graft to the host vessel. The study of compliance (dilatability under pressure) has not been conclusive, especially after a series of recent investigations on vein graft evolution. Lately, the focus has been shifting towards more detailed characteristics, like anastomic behaviour, longitudinal elasticity, and flow-related variables. When the relevant property is identified, it should be included in the criteria for design and use of vascular prostheses.

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Endothelialization of Small-Diameter Vascular Prostheses

Archives of Physiology and Biochemistry ◽

10.3109/13813450312331342274 ◽

2003 ◽

Vol 111 (5) ◽

pp. 415-427 ◽

Cited By ~ 22

Author(s):

Y.J.T van der Zijpp ◽

A.A. Poot ◽

J. Feijen

Keyword(s):

Small Diameter ◽

Vascular Prostheses

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Fabrication and Preliminary Study of a Prototype Bi-Layered Small Diameter Vascular Prosthesis Composed of Nano-Fiber and Silk Fiber

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.843.66 ◽

2013 ◽

Vol 843 ◽

pp. 66-69 ◽

Cited By ~ 1

Author(s):

Hui Jing Zhao ◽

Guo Li Zhou ◽

Zhi Qing Yuan

Keyword(s):

Mechanical Properties ◽

Blood Vessels ◽

Outer Layer ◽

Small Diameter ◽

Peak Stress ◽

Silk Fiber ◽

Content Increase ◽

Peak Strain ◽

Tissue Engineering Scaffolds ◽

Vascular Prostheses

Biomaterials used for vascular prostheses should possess certain strength that can keep the normal blood fluidity, as well as certain flexibility and elasticity that can resist blood pulsation pressure. In order to fabricate small diameter vascular prostheses (SDVP) that possess matchable mechanical properties with natural blood vessels, a bi-layered tubular structure composed of electrospinning blended nanofiber and silk fiber was designed and prepared in this study. The inner layer of the structure, prepared through electrospinning, was composed of Poly (L-lactide-co-ε-caprolactone) (PLCL) and silk fibroin (SF) blended nanofibers. Braided silk tube was used as the outer layer of the structure. Morphological, structural and mechanical properties including peak stress, peak strain, and Youngs modulus of the prototype bi-layered SDVP were characterized initially. Results showed that the diameter range of the blended nanofiber was between 100 and 900 nm, and the fiber diameter increased with the content increase of PLCL. Through blending PLCL together with SF, peak stress and peak strain of the electrospun inner layer were improved, and that of the Youngs modulus decreased. Meanwhile, the outer layer of SDVP was stronger and had higher Youngs modulus. Those mechanical performances of the prototype bi-layered SDVP fabricated in this study are similar to natural blood vessels, which provide a promising biomaterial that could be applied on tubular tissue engineering scaffolds.

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