TRANSPORT RATES OF PROTEINS IN POROUS MATERIALS WITH KNOWN MICROGEOMETRY
TRANSPORT RATES OF PROTEINS IN POROUS MATERIALS WITH KNOWN MICROGEOMETRY
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DOI：
10.1016/s0006-3495(89)82788-2
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发表时间：
1989-01-01
影响因子：
3.4
通讯作者：
LANGER, R
中科院分区：
文献类型：
--
作者：
SALTZMAN, WM;LANGER, R
许多生物和生物技术系统涉及大分子通过复杂的大孔（孔径约为10-100μm）环境的扩散。在本报告中，我们提出并评估了一个用于测量惰性大孔膜中蛋白质转运速率的实验系统。对于这种特定的膜系统，微观几何形状通过孔径分布、位置和方向来表征。尽管蛋白质解吸速率远低于基于连续扩散模型的预期，但我们证明测量的传输速率与蛋白质在复杂的、互连的充满水的孔隙网络中的扩散一致。多孔系统表现出与渗流晶格行为定量一致的过渡行为（均方误差 7%，n = 29）。开发了扩散过程的预测数学模型：这些模型使用渗滤概念来描述孔拓扑结构，使用扩散/溶解的连续模型来描述每个单个孔的蛋白质运动，并测量孔径分布。通过该技术预测了水性收缩大孔中蛋白质运输的有效扩散系数。基于测量和导出的微观结构参数预测的扩散系数与实验测量的扩散系数一致，误差在 2 倍以内。这种方法可用于设计生物应用的多孔聚合物系统以及评估在异质环境中发生质量热、动量或变化的其他生物系统。
Many biological and biotechnological systems involve the diffusion of macromolecules through complicated macroporous (pore size on the order of 10-100 .mu.m) environments. In this report, we present and evaluate an experimental system for measuring the rate of protein transport in an inert, macroporous membrane. For this particular membrane system, the microgeometry was characterized in terms of distribution of pore size, position, and orientation. Although the rate of protein desorption was much less than expected based on continuum diffusion models, we demonstrate that the measured transport rates are consistent with diffusion of protein in a complex, interconnected network of water-filled pores. The porous systems exhibit transitional behavior in quantitative agreement with the behavior of percolation lattices (mean square error 7%, n = 29). Predictive mathematical models of the diffusion process were developed: these models used percolation concepts to describe pore topology, continuum models of diffusion/dissolution to describe protein movement at each single pore, and measured pore size distributions. Effective diffusion coefficients for protein transport in aqueous, constricted macropores were predicted by this technique. Predicted diffusion coefficients, based on measured and derived microstructural parameters, agree with experimentally measured diffusion coefficients within a factor of 2. This approach may be useful in the design of porous polymer systems for biological applications and for evaluating other biological systems where conduction of mass heat, momentum, or change occurs in a heterogeneous environment.