UCL  IRIS
Institutional Research Information Service
UCL Logo
Please report any queries concerning the funding data shown on the profile page to:

http://www.ucl.ac.uk/finance/secure/research/post_award
Please report any queries concerning the student data shown on the profile page to:

Email: portico-services@ucl.ac.uk

Help Desk: http://www.ucl.ac.uk/ras/portico/helpdesk
Publication Detail
Manufacture of small calibre quadruple lamina vascular bypass grafts using a novel automated extrusion-phase-inversion method and nanocomposite polymer
  • Publication Type:
    Journal article
  • Publication Sub Type:
    Article
  • Authors:
    Sarkar S, Burriesci G, Wojcik A, Aresti N, Hamilton G, Seifalian AM
  • Publisher:
    ELSEVIER SCI LTD
  • Publication date:
    16/04/2009
  • Pagination:
    722, 730
  • Journal:
    J BIOMECH
  • Volume:
    42
  • Issue:
    6
  • Print ISSN:
    0021-9290
  • Language:
    EN
  • Keywords:
    Bypass graft, Nanocomposite, Compliance, Viscoelastic, Polymer, Coronary artery, OLIGOMERIC SILSESQUIOXANE NANOCOMPOSITES, MECHANICAL-PROPERTIES, IN-VITRO, POLYURETHANE, FABRICATION, PROSTHESIS, RESISTANCE, COMPLIANT, POROSITY
  • Addresses:
    Seifalian, AM
    UCL
    Ctr Nanotechnol Biomat & Tissue Engn
    UCL Div Surg & Intervent Sci
    Royal Free Hampstead NHS Trust Hosp
    London
    NW3 2PF
    England
Abstract
Long-term patency of expanded polytetrafluoroethylene (ePTFE) small calibre cardiovascular bypass prostheses (<6 mm) is poor because of thrombosis and intimal hyperplasia due to low compliance, stimulating the search for elastic alternatives. Wall porosity allows effective post-implantation graft healing, encouraging endothelialisation and a measured fibrovascular response. We have developed a novel poly (carbonate) urethane-based nanocomposite polymer incorporating polyhedral oligomeric silsesquioxane (POSS) nanocages (UCL-NANO (TM)) which shows anti-thrombogenicity and biostability.We report an extrusion-phase-inversion technique for manufacturing uniform-walled porous conduits using UCL-NANO (TM). Image analysis-aided wall measurement showed that two uniform wall-thicknesses could be specified. Different coagulant conditions revealed the importance of low-temperature phase-inversion for graft integrity. Although minor reduction of pore-size variation resulted from the addition of ethanol or N,N-dimethylacetamide, high concentrations of ethanol as coagulant did not provide uniform porosity throughout the wall. Tensile testing showed the grafts to be elastic with strength being directly proportional to weight. The ultimate strengths achieved were above those expected from haemodynamic conditions, with anisotropy due to the manufacturing process. Elemental analysis by energy-dispersive X-ray analysis did not show a regional variation of POSS on the lumen or outer surface. In conclusion. the automated vertical extrusion-phase-inversion device can reproducibly fabricate uniform-walled small calibre conduits from UCL-NANO (TM). These elastic microporous grafts demonstrate favourable mechanical integrity for haemodynamic exposure and are currently undergoing in-vivo evaluation of durability and healing properties. (C) 2009 Elsevier Ltd. All rights reserved.
Publication data is maintained in RPS. Visit https://rps.ucl.ac.uk
 More search options
UCL Authors
Dept of Mechanical Engineering
University College London - Gower Street - London - WC1E 6BT Tel:+44 (0)20 7679 2000

© UCL 1999–2011

Search by