Bruil A, van Aken W G, Beugeling T, Feijen J, Steneker I, Huisman J G, Prins H K
Department of Chemical Technology, University of Twente, Enschede, The Netherlands.
J Biomed Mater Res. 1991 Dec;25(12):1459-80. doi: 10.1002/jbm.820251205.
As part of a study on the mechanisms of leukocyte filtration, the influence of pore size distribution on filter efficiency was investigated. Conventional leukocyte filters are not suitable for model studies, as these filters are composed of tightly packed synthetic fibers, with a poorly defined porous structure. Therefore, open cellular polyurethane membranes with pore size distributions varying from approximately 15 to 65 microns were prepared. Filtration experiments with stacked packages of these membranes showed that leukocytes are best removed (greater than 99%) by filters with a pore size distribution of 11-19 microns. These pore sizes approach the size of leukocytes (6-12 microns). However, due to fast clogging, blood flow through these filters is rapidly reduced, which results in a low filter capacity. With an asymmetric membrane filter, in which the pore size decreases from about 65 to 15 microns in the direction of blood flow, both moderate removal of leukocytes (greater than 80%) and maintenance of flow (approximately 0.2 mL/s) are obtained. This results in efficient leukocyte removal. From cell analysis of both filtrate and filter, it is concluded that adhesion rather than sieving is the major filtration mechanism. Thus, further optimization of the filter may be achieved by surface modification.
作为白细胞过滤机制研究的一部分，研究了孔径分布对过滤效率的影响。传统的白细胞过滤器不适用于模型研究，因为这些过滤器由紧密堆积的合成纤维组成，其多孔结构定义不明确。因此，制备了孔径分布在约15至65微米之间变化的开孔聚氨酯膜。对这些膜的堆叠组件进行的过滤实验表明，孔径分布为11 - 19微米的过滤器对白细胞的去除效果最佳（大于99%）。这些孔径接近白细胞的大小（6 - 12微米）。然而，由于快速堵塞，通过这些过滤器的血流迅速减少，导致过滤容量较低。使用不对称膜过滤器，其中孔径在血流方向上从约65微米减小到15微米，既可以适度去除白细胞（大于80%），又可以维持血流（约0.2 mL/s）。这导致白细胞的有效去除。从滤液和过滤器的细胞分析得出结论，主要的过滤机制是粘附而非筛分。因此，通过表面改性可以实现过滤器的进一步优化。
