Development and application of heparincontaining supports

CESAR G. GOMEZ; CECILIA I. ALVAREZ IGARZABAL; DARIO ARRUA; MIRIAM C. STRUMIA

Simposio; VII Simp. Latinoam. de Polímeros (SLAP ´02); 2002

In this work, different matrices: poly (ethylene glycol dimethacrylate-2-hydroxyethyl methacrylate) [poly(EGDMA-co-HEMA)] and commercial agarose (Aga), were modified to couple heparin. Poly(EGDMA-co-HEMA) matrix obtained in our labs by suspension copolymerization3-4 constitutes a highly porous crosslinked network. Its total porosity value was 83%, defined as5 %P = V p total d0 x 100. The total specific pore volume was 2.75 mL/g; the total specific surface area was 135.5 m2/g and the sample apparent density (d0) was 0.3 g/mL. These data were obtained from mercury intrusion porosimetry method (pore diameter between 4 - 400000 nm). Different samples of the matrix were activated with 1,4 butanediol diglycidyl ether (BDGE) or epichlorohydrin (ECH) in basic aqueous medium at room temperature, yielding poly(EGDMA-co-HEMA)-BDGE and poly(EGDMA-co-HEMA)-ECH products, that contain 98.6 and 107 µmol epoxy groups/g of dry sample, respectively. The epoxy-activated matrices were reacted with concentrated ammonia solution at 40 C to generate terminal primary amine groups 1, 6-7. Heparin (157 UI/mg) was then coupled on amino-matrices by reductive amination of its terminal formyl groups by incubation in phosphate buffer (pH 7) at room temperature for two days using sodium cyanoborohydride6-8. The amount of coupled heparin was determined by difference between the amount initially added to react and that remained in the reaction final supernatant. It was analyzed by UV-Vis spectrophotometry through the phenol-based method8.