HEPARINIZED POLYURETHANE SURFACE THROUGH IONIC BONDING OF HEPARIN

Surface heparinization through an ionic bond is one of the methods used to improve polyurethane blood compatibility. Chains of poly(amido-amine), a tertiary aminic polymer capable of forming stable complexes with heparin, were either surface-grafted on polyurethane or interconnected with polyurethane chains using hexamethylenediisocyanate as cross-linking agent. In the latter case, a new material (PUPA) is formed with a heparin adsorbing capacity higher than poly (amido-amine) surface-grafted polyurethane. By changing the percentages of the components, different series of PUPA materials can be obtained with different physico-chemical properties. The ATR/FT-IR technique was used to characterize the new materials in the native and in the heparinized state. PUPA solution was used to coat commercial biomedical devices and they were also characterized physico-chemically using ATR/FT-IR.