Summary
Heparin can be bound to polymer surfaces by precipitation of an ionic heparin-amine
complex which can be stabilized against dissolution by treatment with glutardialdehyde.
The aim of this investigation was to study the degree and course of desorption of
heparin from such a heparinized surface on contact with blood. This desorption must
be considered when analysing the interaction between the heparinized surface and blood.
Different heparinized surfaces were prepared by using 35S-labelled heparin, and the desorption of heparin on exposure in vitro to citrated plasma or heparinized blood as well as during exposure at in vivo conditions was quantified.
During in vitro experiments, the glutardialdehyde stabilized surface became stable with no further
desorption of heparin after an initial loss of about 3% of the initial surface-bound
heparin. Under in vivo conditions, there was an initial loss of about 12%. There was no further loss from
surfaces inserted into the circulation of the dog for seven days as compared to those
inserted for one hour.
