CORRELATION OF THE SURFACE CHEMISTRIES OF POLYMER BIOACTIVE COATINGS,WITH THEIR BIOLOGICAL PERFORMANCES

Surface analysis techniques have been used to characterize heparin-con taining bioactive coatings. The relationship between uncoated polymer, intermediate coupling and final layer surface chemistry upon the over all quality of the coating system has been investigated. The results p resent data from ToFSIMS, XPS and bioactivity in terms of thrombin dea ctivation as measured using chromogenic assay technique on heparin-bas ed coatings on polymer surfaces including LDPE and PVC. The effect of pretreatment of uncoated polymer surfaces has been investigated where a number of effects critical to coating performance have been identifi ed. Sti!dies of the intermediate coupling regime show how the first an d final stages of coupling are the most critical. Finally it is shown how the integrity, mean thickness and chemical state of the heparin fi nal layer can be measured using a combination of ToFSIMS and XPS.