In Vitro and in Vivo Biodurability of a Compliant Microporous Vascular Graft

Edwards, A. J.; Carson, Robert J.; Szycher, Michael; Bowald, Staffan

doi:10.1177/088532829801300102

Cited by 55 publications

(35 citation statements)

References 18 publications

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“…CPU grafts showed no such changes with regard to the H 2 O 2 /CoCl 2 mixture, confirming the earlier experiences of Edwards and coworkers. 27,41 However, CPU grafts did show significant differences in compliance with regard to Glut/tbut/CoCl 2 . Although compliance measurements have previously been used to characterize the physical properties of polyurethane grafts in the virgin state, 41,42 this result indicates that such measurements may also provide a qualitative indicator of change in material character.…”

Section: Behaviour Of Cpu and Pulse-tec Upon Oxidation And Peroxidationmentioning

confidence: 87%

“…2). 26,27 The chemicals are added sequentially, including a watersoluble porosifier (10-60 wt %) and a surfactant (1-10 wt %), onto the surface of a rotating and transversing steel mandrel. The mandrel and extrusion head rotate synchronously minimizing shear and residual stress, while a pair of 2.5-m-long mandrels are drawn through twin extrusion heads into a coagulant maintained at 40°C.…”

Section: Graft Materialsmentioning

confidence: 99%

“…12 With these in vitro methods, CPU grafts have previously exhibited superior survivability and no catastrophic failure (n = 10) after 250 days over poly(ether)urethane controls, whereas all samples (n = 10) failed catastrophically between 47 and 169 days. 27 In this study, grafts were exposed to simple solutions capable of generating several oxidizing freeradical species, including hydroxyl ( и OH), superoxide, and singlet oxygen species from H 2 O 2 /CoCl 2 .…”

Section: Behaviour Of Cpu and Pulse-tec Upon Oxidation And Peroxidationmentioning

confidence: 99%

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In vitro stability of a novel compliant poly(carbonate‐urea)urethane to oxidative and hydrolytic stress

Salacinski

Tai

Carson³

et al. 2001

J. Biomed. Mater. Res.

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Poly(ester)urethane and poly(ether)urethane vascular grafts fail in vivo because of hydrolytic and oxidative degradative mechanisms. Studies have shown that poly(carbonate)urethanes have enhanced resistance. There is still a need for a viable, nonrigid, small-diameter, synthetic vascular graft. In this study, we sought to confirm this by exposing a novel formulation of compliant poly(carbonate-urea)urethane (CPU) manufactured by an innovative process, resulting in a stress-free. Small-diameter prosthesis, and a conventional poly(ether)urethane Pulse-Tec graft known to readily undergo oxidation in a variety of degradative solutions, and we assessed them for the development of oxidative and hydrolytic degradation, changes in elastic properties, and chemical stability. To simulate the in vivo environment, we used buffered solutions of phospholipase A(2) and cholesterol esterase; solutions of H(2)O(2)/CoCl(2), t-butyl peroxide/CoCl(2) (t-but/CoCl(2)), and glutathione/t-butyl peroxide/CoCl(2) (Glut/t-but/CoCl(2)); and plasma fractions I-IV, which were derived from fresh human plasma centrifuged in poly(ethylene glycol). To act as a negative control, both graft types were incubated in distilled water. Samples of both graft types (100 mm with a 5.0-mm inner diameter) were incubated in these solutions at 37 degrees C for 70 days before environmental scanning electron microscopy, radial tensile strength and quality control, gel permeation chromatography, and in vitro compliance assessments were performed. Oxidative degradation was ascertained from significant changes in molecular weight with respect to a control on all Pulse-Tec grafts treated with t-but/CoCl(2), Glut/t-but/CoCl(2), and plasma fractions I-III. Pulse-Tec grafts exposed to the H(2)O(2)/CoCl(2) mixture had significantly greater compliance than controls incubated in distilled water (p < 0.001 at 50 mmHg). No changes in molecular weight with respect to the control were observed for the CPU samples; only those immersed in t-but/CoCl(2) and Glut/t-but/CoCl(2) showed an 11% increase in molecular weight to 108,000. Only CPU grafts treated with the Glut/t-but/CoCl(2) mixture exhibited significantly greater compliance (p < 0.05 at 50 mmHg). Overall, results from this study indicate that CPU presents a far greater chemical stability than poly(ether)-urethane grafts do.

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Section: Behaviour Of Cpu and Pulse-tec Upon Oxidation And Peroxidationmentioning

confidence: 87%

Section: Graft Materialsmentioning

confidence: 99%

Section: Behaviour Of Cpu and Pulse-tec Upon Oxidation And Peroxidationmentioning

confidence: 99%

See 1 more Smart Citation

In vitro stability of a novel compliant poly(carbonate‐urea)urethane to oxidative and hydrolytic stress

Salacinski

Tai

Carson³

et al. 2001

J. Biomed. Mater. Res.

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show abstract

“…Coronary bypass surgery has been accepted as one of the surgical treatment methods in the case of occluded coronary arteries. Various types of synthetic polymers have been employed to prepare vascular grafts, among which some have been effective in fabricating such large-diameter (> 6 mm) vascular substitutes as Dacron (poly(ethylene teraphthalate)), expanded poly(tetrafluoroethylene) (ePTFE), and microporous polyurethanes [1][2][3]. However, in the case of small-diameter vascular grafts, there are relatively few successful examples mainly due to the rapid occlusion caused by thrombosis and intimal hyperplasia [3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Core-shell fibrous vascular grafts with the nitric oxide releasing property

et al. 2010

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Small-diameter vascular grafts with the nitric oxide (NO) releasing property were designed and prepared. Diazeniumdiolated N,N′-dibutyl-1,6-hexanediamine (DBHD/N 2 O 2 ) was first synthesized as the NO donor and doped into the biocompatible polymer poly(-caprolactone) (PCL). The fibrous vascular grafts were fabricated by electrospinning. Despite the reduced platelet adhesion observed on the NO releasing grafts, the cytotoxicity and burst release were apparent, especially at a higher loading level of the NO donor. In order to solve this problem, core-shell structured nanofibers, in which PCL or gelatin is the shell and PCL doped with the NO donor is the core, were fabricated via coaxial electrospinning. The core-shell structure made the NO release more steady and controllable, and the cell compatibility was improved.nitric oxide release, coaxial electrospinning, platelet adhesion, vascular graft

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“…2 Scanning electron microscopy (SEM) was performed by the group but in none of the figures incorporated into the text are any features visible in the graft resembling pitting, etching, or environmental stress cracking, which are known indicators of instability. 3 In Figure 13 of the article a photograph of the graft that was explanted from a sheep is presented in the Discussion section, where it is stated that "the graft material lost its cylindrical shape. The material is curved, radially expanded, and shows signs of chemical breakdown."…”

mentioning

confidence: 99%