Bruil A, Oosterom H A, Steneker I, Al B J, Beugeling T, van Aken W G, Feijen J
Department of Chemical Technology, University of Twente, Enschede, The Netherlands.
J Biomed Mater Res. 1993 Oct;27(10):1253-68. doi: 10.1002/jbm.820271006.
Polyurethane membrane filters and filters coated with poly(ethyleneimine) were used to investigate the influence of leukocyte adhesion during filtration. Treatment of the filters with an aqueous solution of 1% (w/v) poly(ethyleneimine) (PEI) led to the introduction of amine groups at the filter surfaces, as was confirmed by X-ray photoelectron spectroscopy. The modification procedure did not significantly change the porous structure in the filters, as was demonstrated by SEM and porometry. Using 14C-labeled poly(ethyleneimine) it was shown that nearly a complete coverage (approximately 0.1 mg/m2) was achieved that did not desorb from the filter surface during contact with blood plasma. When the filtration was carried out with purified leukocytes in the absence of red cells, platelets, and blood plasma, the number of cells removed by modified filters (> 95%) was significantly higher as compared to the removal with unmodified filters (approximately 80%). However, no significant differences between the filters were found when the filtration was performed with whole blood. This finding was unexpected, because it was shown before that immobilization of poly(ethyleneimine) on solid polyurethane film, surfaces promoted the adhesion of leukocytes from whole blood. Apparently, the adhesive properties of the PEI diminish during filtration. Filter coating of commercial leukocyte filters composed of polyester fibers also had no effect on the removal of leukocytes from whole blood. It was postulated that morphological factors, such as filter shape, roughness, tortuosity, and porosity rather than the physicochemical properties of the filter surface influence cell adhesion to the filter surface, and through that the filtration process.
使用聚氨酯膜过滤器和涂有聚乙烯亚胺的过滤器来研究过滤过程中白细胞黏附的影响。用1%（w/v）聚乙烯亚胺（PEI）水溶液处理过滤器会导致在过滤器表面引入胺基，这通过X射线光电子能谱得到证实。扫描电子显微镜和孔隙率测定表明，改性过程并未显著改变过滤器的多孔结构。使用14C标记的聚乙烯亚胺表明，实现了几乎完全覆盖（约0.1 mg/m2），且在与血浆接触期间不会从过滤器表面解吸。当在没有红细胞、血小板和血浆的情况下用纯化的白细胞进行过滤时，与未改性过滤器（约80%）相比，改性过滤器去除的细胞数量（>95%）显著更高。然而，当用全血进行过滤时，未发现过滤器之间存在显著差异。这一发现出乎意料，因为之前表明将聚乙烯亚胺固定在固体聚氨酯膜表面会促进全血中白细胞的黏附。显然，PEI的黏附特性在过滤过程中会减弱。由聚酯纤维组成的商用白细胞过滤器的滤器涂层对从全血中去除白细胞也没有影响。据推测，形态学因素，如过滤器形状、粗糙度、曲折度和孔隙率，而非过滤器表面的物理化学性质，会影响细胞对过滤器表面的黏附，并由此影响过滤过程。
