Immobilization of heparin oligosaccharides onto radiofrequency plasma modified pyrolytic carbon-coated graphite.
Immobilization of heparin oligosaccharides onto radiofrequency plasma modified pyrolytic carbon-coated graphite.
复制标题
将肝素寡糖固定在射频等离子体改性的热解碳涂层石墨上。
DOI：
10.1002/jab.770060407
复制
发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Marchant,RE
中科院分区：
文献类型：
--
作者：
Yuan,S;Cai,W;Szakalas-Gratzl,G;Kottke-Marchant,K;Tweden,K;Marchant,RE
制备了具有不同抗凝活性的肝素低聚糖，并将其固定在机械瓣膜常用的热解碳包覆石墨(PC)心脏瓣膜材料上。在固定化之前，用射频等离子体聚合的N-乙烯-2-吡咯烷酮(∼)薄膜(PPNVP)对PC表面进行修饰，并衍生化以提供表面羟基。以市售粗肝素为原料，通过部分脱氨基裂解制备了Xa因子抑制活性为107~130IU/mg的裂解低亲和力肝素(C-肝素)，通过琼脂糖亲和层析分离得到了Xa抑制活性为550~1000IU/mg的高亲和力肝素(HA-肝素)。采用还原胺化的方法将C-肝素和HA-肝素固定到表面修饰的PC上。采用发色法测定固定化肝素表面对凝血因子Xa的抑制作用。C-肝素固定化表面的抗凝血活性(64.0±7.3mIU/cm2)高于HA-肝素固定化表面(27.2±12.2mIU/cm2)，表明C-肝素比HA-肝素在修饰后的PC表面具有更高的结合力。在5%白蛋白溶液或人血浆存在的情况下，通过对样品施加高达206dyn/cm2的剪应力，在动态流动条件下对固定化表面进行评估。固定化肝素的抗凝血活性虽然有所降低，但仍保持不变，而且修饰后的表面显示出对蛋白质的抗性。©1995 John Wiley&Sons，Inc.
Heparin oligosaccharides with different anticoagulant activities were prepared and immobilized onto pyrolytic carbon coated graphite (PC) heart valve materials commonly used in mechanical heart valve prostheses. Prior to immobilization, PC surfaces were modified by radio‐frequency plasma polymerizedN‐vinyl‐2‐pyrrolidone (PPNVP) thin films (∼ 100 nm) and derivatized to provide surface hydroxyl groups. Cleaved, low affinity heparin (C‐heparin) with factor Xa inhibition activity of 107 to 130 IU/mg, was prepared by partial deaminative cleavage of commercial crude heparin, and high‐affinity heparin (HA‐heparin) with factor Xa inhibition activity of 550 to 1000 IU/mg was prepared by fractionation of C‐heparin using agarose‐ATIII affinity chromatography. C‐heparin and HA‐heparin were immobilized to surface modified PC by reductive amination. Anticoagulant activity of the heparin immobilized surfaces was determined by chromogenic assay for the inhibition of factor Xa. Highest surface anticoagulant activity was measured on C‐heparin immobilized surfaces (64.0 ± 7.3 mIU/cm2) compared with HA‐heparin immobilized surfaces (27.2 ± 12.2 mIU/cm2), suggesting higher binding of C‐heparin than HA‐heparin on the modified PC surfaces. Immobilized surfaces were evaluated under dynamic flow conditions, by subjecting samples to shear stress of up to 206 dyn/cm2in the presence of 5% albumin solution or human plasma. Anticoagulant activity of the immobilized heparin was retained, although reduced, and the modified surfaces showed evidence for protein resistance. © 1995 John Wiley & Sons, Inc.