Boyd R F, Langsdorf L J, Zydney A L
Department of Chemical Engineering, University of Delaware, Newark 19716, USA.
ASAIO J. 1994 Jul-Sep;40(3):M864-9. doi: 10.1097/00002480-199407000-00120.
The performance of many artificial organs can be strongly affected by the transport characteristics of the semi-permeable membranes used in these devices, but there is little data on the effects of blood contact on membrane transport properties. Experimental data were obtained for the solute flux through cellulosic, polyacrylonitrile, and polyethersulfone membranes using polydispersed dextrans. Blood contact had a very large effect on diffusive solute transport through the asymmetric polyethersulfone membranes, but only a small effect on diffusion through the symmetric AN69 and Cuprophan membranes. In contrast, blood contact caused a similar reduction in convective solute transport (sieving) through both the polyethersulfone and AN69 membranes. Convective transport through the blood contacted membranes was also dependent on the flow direction, with greater transport obtained when the membrane was oriented with the blood contacted surface downstream. These data were analyzed using a two layer membrane model consisting of an upper layer of blood cells and proteins adsorbed to the surface of the native membrane. This model accurately accounted for the different effects of blood contact on convection and diffusion, as well as the observed asymmetry in convective solute transport. These results have important implications for the analysis of solute transport in artificial organs.
许多人工器官的性能会受到这些装置中使用的半透膜传输特性的强烈影响，但关于血液接触对膜传输特性影响的数据却很少。使用多分散葡聚糖获得了通过纤维素、聚丙烯腈和聚醚砜膜的溶质通量的实验数据。血液接触对通过不对称聚醚砜膜的扩散溶质传输有很大影响，但对通过对称的AN69和铜氨膜的扩散影响很小。相比之下，血液接触导致通过聚醚砜膜和AN69膜的对流溶质传输（筛分）有类似程度的降低。通过与血液接触的膜的对流传输也取决于流动方向，当膜的血液接触表面位于下游时，传输量更大。使用由吸附在天然膜表面的血细胞和蛋白质上层组成的两层膜模型对这些数据进行了分析。该模型准确地解释了血液接触对对流和扩散的不同影响，以及对流溶质传输中观察到的不对称性。这些结果对人工器官中溶质传输的分析具有重要意义。
