Venkataramani E S, Senatore F, Feola M, Tran R M
Surgery. 1986 Jun;99(6):735-43.
The present investigation demonstrates covalent binding of heparin with carbodiimide to ammonium hydroxide-treated collagenous surfaces. Human umbilical vein grafts (HUVG) outperform carotid arteries of goat, porcine, and canine origin in both heparin loading and stability of the immobilized heparin preparation. The average heparin loading on the untreated carotid arteries and HUVGs and ammonium hydroxide-treated HUVGs were 18, 27, and 31.5 micrograms/cm2, respectively. There was negligible loss of heparin activity under in vitro and in vivo conditions. In vitro studies demonstrate that heparin-bound HUVGs discourage platelet adhesion and subsequent fibrin clot formation. In vivo studies with heparin-bound HUVGs show a significant increase in thrombus-free surface compared with control grafts. Heparin-bound HUVGs also show an enhanced patency rate in the two sets of protocols tested--one lasting for 3 in vivo days (seven grafts) and the other lasting for 7 (15 grafts) in vivo days. The studies conducted so far demonstrate the promise of developing a nonthrombogenic small-caliber HUVG prosthesis.
本研究证明了肝素与碳二亚胺共价结合于氢氧化铵处理过的胶原表面。人脐静脉移植物（HUVG）在肝素负载量和固定化肝素制剂的稳定性方面均优于山羊、猪和犬来源的颈动脉。未经处理的颈动脉、HUVG以及氢氧化铵处理过的HUVG上肝素的平均负载量分别为18、27和31.5微克/平方厘米。在体外和体内条件下，肝素活性的损失可忽略不计。体外研究表明，结合肝素的HUVG可抑制血小板黏附及随后的纤维蛋白凝块形成。结合肝素的HUVG的体内研究显示，与对照移植物相比，无血栓表面显著增加。结合肝素的HUVG在两组测试方案中也显示出更高的通畅率——一组体内持续3天（7个移植物），另一组体内持续7天（15个移植物）。迄今为止进行的研究表明，开发一种非血栓形成的小口径HUVG假体具有前景。
