Riedel Tomás, Brynda Eduard, Dyr Jan E, Houska Milan
Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
J Biomed Mater Res A. 2009 Feb;88(2):437-47. doi: 10.1002/jbm.a.31755.
A technique for coating surfaces with attached fibrin structures without the formation of fibrin gel in bulk solution was developed. It is based on the catalytic effect of the surface-bound thrombin on fibrinogen stabilized with inhibitor which inhibits thrombin in solution but not the thrombin on the surface. Such an inhibitor is antithrombin, the effect of which may be enhanced with heparin. Fibrinogen is first adsorbed on the substrate surface and then incubated with thrombin. The unbound thrombin is washed out and the surface is incubated with fibrinogen solution containing antithrombin III and heparin. A fibrin gel forms at the surface by the action of surface-bound thrombin on ambient fibrinogen solution; however, the gel formation in bulk solution catalyzed by thrombin partially released from the surface is suppressed. By utilizing antithrombin-independent inhibitors or repeating thrombin binding and incubation with fibrinogen solution, the amount of surface-attached fibrin gel can be controlled. The formation of immobilized fibrin networks was observed using surface plasmon resonance and turbidity measurements and morphology was observed by TEM, SEM, and AFM. Using this technique, a porous scaffold made of polylactide fibers was coated with fibrin without filling the space between fibers with a bulk fibrin gel. The technique makes it possible to coat the inner surface of porous scaffolds with surface-attached fibrin gel while preserving free volume for cell migration into the pores.
开发了一种在表面涂覆附着有纤维蛋白结构的技术，而不会在大量溶液中形成纤维蛋白凝胶。它基于表面结合的凝血酶对用抑制剂稳定的纤维蛋白原的催化作用，该抑制剂可抑制溶液中的凝血酶，但不抑制表面上的凝血酶。这样的抑制剂是抗凝血酶，其作用可通过肝素增强。首先将纤维蛋白原吸附在底物表面，然后与凝血酶一起孵育。洗去未结合的凝血酶，然后将表面与含有抗凝血酶III和肝素的纤维蛋白原溶液一起孵育。表面结合的凝血酶作用于周围的纤维蛋白原溶液，在表面形成纤维蛋白凝胶；然而，从表面部分释放的凝血酶催化的大量溶液中的凝胶形成受到抑制。通过使用不依赖抗凝血酶的抑制剂或重复凝血酶结合并与纤维蛋白原溶液孵育，可以控制表面附着的纤维蛋白凝胶的量。使用表面等离子体共振和浊度测量观察固定化纤维蛋白网络的形成，并通过透射电子显微镜（TEM）、扫描电子显微镜（SEM）和原子力显微镜（AFM）观察形态。使用该技术，由聚丙交酯纤维制成的多孔支架被纤维蛋白包被，而不会用大量纤维蛋白凝胶填充纤维之间的空间。该技术使得可以用表面附着的纤维蛋白凝胶涂覆多孔支架的内表面，同时保留用于细胞迁移到孔中的自由体积。
