Grainger D W, Kim S W, Feijen J
Department of Pharmaceutics, University of Utah, Salt Lake City.
J Biomed Mater Res. 1988 Mar;22(3):231-49. doi: 10.1002/jbm.820220307.
Amphiphilic block copolymers containing poly(dimethylsiloxane), poly(ethylene oxide), and heparin (PDMS-PEO-Hep) have been prepared via a series of coupling reactions using functionalized prepolymers, diisocyanates, and derivatized heparins. All intermediate steps of the synthesis yield quantifiable products with reactive end-groups, while the final products demonstrate bioactive, covalently bound heparin moieties. Due to the solvent systems required, commercial sodium heparin was converted to its benzyltrimethyl ammonium salt to enhance its solubility. The same procedure was applied to heparin degraded by nitrous acid in order to covalently couple it in solutions with the semitelechelic copolymers. As might be expected, this derivatization reduces the apparent bioactivity of the heparin. However, preliminary findings suggest that the bioactivity can be restored by reforming the heparin sodium salt.
含有聚二甲基硅氧烷、聚环氧乙烷和肝素（PDMS-PEO-Hep）的两亲性嵌段共聚物是通过一系列偶联反应制备的，反应中使用了官能化预聚物、二异氰酸酯和衍生化肝素。合成的所有中间步骤都能产生具有可量化的、带有反应性端基的产物，而最终产物则显示出具有生物活性的、共价连接的肝素部分。由于所需的溶剂体系，将市售肝素钠转化为其苄基三甲基铵盐以提高其溶解度。将相同的程序应用于经亚硝酸降解的肝素，以便将其在溶液中与半遥爪共聚物共价偶联。正如预期的那样，这种衍生化降低了肝素的表观生物活性。然而，初步研究结果表明，通过重新形成肝素钠盐可以恢复其生物活性。
