Preparation of heparin-immobilized PVA and its adsorption for low-density lipoprotein from hyperlipemia plasma

Abstract

In this study, heparin was covalently coupled by glutaraldehyde to Poly(vinyl alcohol) [PVA] in solid-liquid two-phase reaction system by two-step synthesis method to prepare a LDL-selective adsorbent. The parameters (the material ratio, reaction time and dosage of catalyzer) were investigated to evaluate their effect upon the immobilized amount of heparin onto the surface of PVA, IR was used to verify the covalent immobilization result and the heparin-modified PVA was also undergone the evaluation of its adsorption capability for low-density lipoprotein from hyperlipemia plasma, and its hemocompatibility was preliminarily evaluated by platelet adhesion test. Results showed: (1) under optimized reaction conditions the highest immobilization amount of heparin onto PVA surface within the experiments of this study has been obtained; (2) the optimized reaction conditions were: (i) at the refluxing temperature 78 degrees C; (ii) the material ratio of "PVA(g): 50% glutaraldehyde (ml)" was about "1:3"; (iii) the reaction time was about 5 h; and (iv) the amount of catalyzer (concentrated HCL) was about 1% of the 50% glutaraldehyde; (3) within the experiments of this study the highest immobilization amount would be up to 25 microg heparin on the surface of per g PVA granules; (4) the heparin-modified PVA granules showed significant adsorption for LDL under faintly alkaline environment (pH=7.2-9.5) ; (5) The result of platelet adhesion test showed no platelet adhered to its surface. Therefore, immobilization of heparin onto the surface of a support is one approach to prepare a kind of LDL adsorbent for blood purification.