Chandy T, Sharma C P
J Biomed Mater Res. 1984 Nov-Dec;18(9):1115-24. doi: 10.1002/jbm.820180913.
For intravascular implantation, a biofunctional surface seems to retard surface thrombosis upon synthetic materials. Prostaglandins, like PGI2, PGE1, and PGD2, etc., are believed to stimulate membrane-bound adenyl cyclase and thereby raise intracellular levels of c-AMP within platelets, which inhibit platelet adhesion and aggregation. A new procedure is suggested for the immobilization of prostaglandin E1 on an albuminated polymer matrix, through glutaraldehyde coupling. Materials thus prepared show dramatic antiplatelet effects, with regard to platelet adhesion, when compared with albumin-immobilized surfaces. The affinity of various modified surfaces toward platelet adhesion is studied, using washed platelets suspended in Tyrode's solution. Octane contact angle studies are used to develop an understanding of the varied nature of bound substrates at equilibrium on polymer surfaces. These are studied at the solid/liquid interface, which is closest to in vivo conditions. The plasma recalcification time demonstrates the anticoagulant properties of various surfaces. A possible role of PGE1 in reducing platelet activity in the presence and absence of vitamin C is discussed. This technique may be used in the development of non-thrombogenic surfaces on existing biomedical polymers. Simultaneous pharmaceutical modification of the blood with vitamin C may enhance the blood compatibility of the surface.
对于血管内植入,生物功能表面似乎能延缓合成材料表面的血栓形成。前列腺素,如前列环素(PGI2)、前列腺素E1(PGE1)和前列腺素D2(PGD2)等,被认为可刺激膜结合腺苷酸环化酶,从而提高血小板内的环磷酸腺苷(c-AMP)水平,抑制血小板黏附和聚集。有人提出一种新方法,通过戊二醛偶联将前列腺素E1固定在白蛋白化聚合物基质上。与固定白蛋白的表面相比,用这种方法制备的材料在血小板黏附方面显示出显著的抗血小板作用。使用悬浮在台氏液中的洗涤血小板,研究各种改性表面对血小板黏附的亲和力。通过辛烷接触角研究来了解聚合物表面平衡时结合底物的不同性质。这些研究是在最接近体内条件的固/液界面进行的。血浆复钙时间表明了各种表面的抗凝特性。讨论了在有和没有维生素C存在的情况下,PGE1在降低血小板活性方面可能发挥的作用。该技术可用于在现有生物医学聚合物上开发非血栓形成表面。同时用维生素C对血液进行药物改性可能会增强表面的血液相容性。