肝素和聚氨酯同溶液体系混合接枝及其抗凝血性

利用全新的四氢呋喃和水的溶液体系将肝素与不溶于水的聚氨酯同溶液混合,制备出含有肝素的聚氨酯薄膜利用碳二亚胺缩合反应将肝素接枝在聚氨酯分子上以改善材料的长效抗凝血性.在肝素过量的情况下,制备出同时含有游离和接枝肝素的聚氨酯薄膜,并初步评价了薄膜中肝素的扩散速率以及体外抗凝血性.结果表明,肝素均匀分布在薄膜中,肝素活性保持良好,扩散缓慢,具有相对长效的抗凝血活性.接枝后的肝素仍具有良好的生物活性,同时含有接枝和游离肝素薄膜的抗凝血性优异.

Preparation and blood compatibility of polyurethane films blending and grafting with heparin in the same solvent system

Heparin homogeneously mixed with polyurethane in the co-solvent of tetrahydrofuran and water through adjusting the ratio of the two solvents. After the film was prepared with casting method, heparin was homogeneously blended in polyurethane films. At the same time, through preac-tion of heparin with l-(3-dimethyl aminoprophyl)-3-ethylcarbodimide hydrochloride (DCCI), heparin partly grafted with the residual of polyurethane and the films containing free and covalent heparin was obtained using solvent casting. The heparin release rate was investigated with toluidine blue heparin assay (TBHA). The blood compatibility of polyurethane films was assessed with thrombin time (TT), prothrombin time (PT) and activated partial thromboplastin time (APTT). The results indicated that polyurethane containing heparin showed expected blood compatibility and polyurethane containing free and covalent heparin had the excellent bioactivity of free heparin and the long-term blood compatibility of covalent heparin.