NUK - logo
(UM)
  • Surface properties of PET vascular grafts [Elektronski vir]
    Indest, Tea ...
    Considerable progress has been achieved in manufacturing of vascular prostheses with required flexibility and mechanical durability. However the number of postoperative complications after surgical ... implantation is related to insufficient blood compatibility of polymer surfaces, resulting in thrombotic occlusion especially when small diameter vascular prostheses are involved. The walls of natural blood vessels are coated with endothelium, which is an ideal non-thrombogenic blood contacting surface due to the fact that it takes part in synthesis of anti-thrombogenic and anticoagulation substances. The logical way to improve the biocompatibility of vascular prostheses is to generate polymers by surface modification adsorbing preferably endothelial cells and marginally adsorbing fibrinogen. At present time, various polymer coatings (collagen, heparin, etc.), surface modifications, and preoperative treatments of prostheses are used extensively in order to enhance adhesion of endothelial cells and to obtain surfaces similar to that of natural blood vessels. This study was focused on differences between woven and knitted PET vascular grafts which surfaces are differently modified - coated with collagen and/or heparin. As a research model, in surgical treatments mostly applied PET vascular grafts have been chosen. The molecular weight and mechanical properties (Iinear density, tenacity, elongation) of fibres in woven and knitted vascular grafts were determined. The surface morphology of applied grafts was investigated using microscopic image processing and analysis. Surface electrokinetic properties of uncoated and with collagen coated grafts were evaluated using streaming potential measurements and on the basis of the differential scanning calorimetry (DSC) some structural parameters of fibres (amorphous/crystalline ratio) were evaluated. The results showed basic differences in appearance and mechanical properties of fibres composing woven or knitted grafts as also in appearance of inner and outer graft's surfaces. In comparison with fibres in knitted grafts, those in woven grafts are thicker (by about 23%), their lineardensity and tensile strength are higher (by about 25% and 7%) and elongation and initial modulus are lower (by about 25% and 55%). There are no significant differences in melting points of fibres from both grafts but the crystallinity degree of fibres in woven graft is higher by about 8%.
    Source: Fibre-grade polymers, chemical fibres and special textiles : proceedings [Elektronski vir] ([4] f.)
    Type of material - conference contribution
    Publish date - 2003
    Language - english
    COBISS.SI-ID - 8200726

Shelf entry