Heparinized Polyurethane Surface through Ionic Bonding of Heparin

Abstract

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 physicochemically using ATR/FT-IR.

In vitro study of blood-contacting properties and effect on bacterial adhesion of a polymeric surface with immobilized heparin and sulphated hyaluronic acid

“…In our case, native PUPA at body pH induced conformational changes in adsorbed brinogen [26]. With PUPA -heparin and PUPA -HyalS 3:5 , the amount of the adsorbed protein was low and did not cause conformational changes [49].…”

“…PUPA was synthesised as described elsewhere [26,31]. Brie y, a 10% solution of Pellethane (2363-80AE) (PU) (Dow Chemical, Delft, The Netherlands) in N;N -dimethyl formamide (DMF) was added to a methylene chloride solution of poly(amido-amine) (N 2 LL) with terminal free isocyanate groups.…”

“…PUPA consists of poly(amido-amine) (N 2 LL) connected with PU chains via hexamethylene diisocyanate (HMDI) [26]. PUPA has the heparin-complexing ability of N 2 LL, binding large amounts of heparin, even when used to coat the surfaces of commercial materials [27].…”

“…PUPA has the heparin-complexing ability of N 2 LL, binding large amounts of heparin, even when used to coat the surfaces of commercial materials [27]. Heparin binds to the PUPA surface by a tight electrostatic bond and physical adsorption [26]. Sulphated hyaluronic acid, a polymer obtained by sulphation of the natural glycosaminoglycan hyaluronic acid, has heparin-like anticoagulant activity; does not induce platelet aggregation and activation, even at very high concentrations of the polymer in solution; and is resistant to enzymatic degradation [28][29][30].…”

Poly(amidoamine)s: Past, present, and perspectives

“…Mixed poly(urethane-PAA) networks, named PUPA, were more extensively studied. [128][129][130][131][132][133][134][135][136] These materials were prepared by first treating A-PAA with excess diisocyanate in chloroform solution and subsequently coupling the resultant isocyanate-terminated PAA with a commercial polyurethane via the CONH groups of the latter (Scheme 6).…”