Covalent binding of heparin to functionalized PET materials for improved haemocompatibility

Metod Kolar*, Miran Mozetič, Karin Stana Kleinschek, Mirjam Fröhlich, Boris Turk, Alenka Vesel

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The hemocompatibility of vascular grafts made from poly(ethylene terephthalate) (PET) is insufficient due to the rapid adhesion and activation of blood platelets that occur upon incubation with whole blood. PET polymer was treated with NHx radicals created by passing ammonia through gaseous plasma formed by a microwave discharge, which allowed for functionalization with amino groups. X-ray photoelectron spectroscopy characterization using derivatization with 4-chlorobenzaldehyde indicated that approximately 4% of the -NH2 groups were associated with the PET surface after treatment with the gaseous radicals. The functionalized polymers were coated with an ultra-thin layer of heparin and incubated with fresh blood. The free-hemoglobin technique, which is based on the haemolysis of erythrocytes, indicated improved hemocompatibility, which was confirmed by imaging the samples using confocal optical microscopy. A significant decrease in number of adhered platelets was observed on such samples. Proliferation of both human umbilical vein endothelial cells and human microvascular endothelial cells was enhanced on treated polymers, especially after a few hours of cell seeding. Thus, the technique represents a promising substitute for wet-chemical modification of PET materials prior to coating with heparin.

Original languageEnglish
Pages (from-to)1526-1544
Number of pages19
Issue number4
Publication statusPublished - 1 Jan 2015
Externally publishedYes


  • Biocompatibility
  • Endothelization
  • Functionalization
  • Haemolysis
  • Heparin
  • Plasma
  • Platelet adhesion
  • Poly(ethylene terephthalate)
  • Vascular graft

ASJC Scopus subject areas

  • Materials Science(all)

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