Zhao Cunyi, Si Yang, Zhu Shenghan, Bradley Kevin, Taha Ameer Y, Pan Tingrui, Sun Gang
Department of Biological and Agricultural Engineering, University of California, Davis, CA 95616, USA.
Department of Food Science and Technology, University of California, Davis, CA 95616, USA.
ACS Appl Polym Mater. 2021 Mar 12;3(3):1618-1627. doi: 10.1021/acsapm.0c01394. Epub 2021 Feb 23.
Porous nanofibrous membranes have ultrahigh specific surface areas and could be broadly employed in protein purification, enzyme immobilization, and biosensors with enhanced selectivity, sensitivity, and efficiency. However, large biomolecules, such as proteins, have hindered diffusion behavior in the micro-porous media, significantly reducing the benefits provided by the nanofibrous membranes. The study of protein diffusion in polyacrylonitrile (PAN) nanofibrous membranes produced under varied humidity and polymer concentration of electrospinning revealed that heterogeneous structures of the nanofibrous membranes possess much smaller effective pore sizes than the measured pore sizes, which significantly affects the diffusion of large molecules through the system though sizes of proteins and pH conditions also have great impacts. Only when the measured membrane pore size is at least 1000 times higher than the protein size, the diffusion behavior of the protein is predictable in the system. The results provide insights into the design and applications of proper nanofibrous materials for improved applications in protein purification and immobilizations.
多孔纳米纤维膜具有超高的比表面积，可广泛应用于蛋白质纯化、酶固定化以及具有更高选择性、灵敏度和效率的生物传感器中。然而，诸如蛋白质等大分子在微孔介质中存在扩散阻碍行为，这显著降低了纳米纤维膜所带来的优势。对在不同湿度和静电纺丝聚合物浓度条件下制备的聚丙烯腈（PAN）纳米纤维膜中蛋白质扩散的研究表明，纳米纤维膜的异质结构具有比测量孔径小得多的有效孔径，这显著影响了大分子在该系统中的扩散，尽管蛋白质大小和pH条件也有很大影响。只有当测量的膜孔径至少比蛋白质大小高1000倍时，蛋白质在系统中的扩散行为才是可预测的。这些结果为设计和应用合适的纳米纤维材料以改善蛋白质纯化和固定化应用提供了见解。
