Abstract Separation of bovine serum albumin (BSA) and hemoglobin (Hb), two proteins with almost identical molecular weight, has been a big challenge for more than two decades. Using traditional ultrafiltraion membranes separation of these proteins is possible only at the isoelectric point of one protein via electrostatic repulsion between the membrane and the other protein. Here we introduce an integral asymmetric isoporous membrane from polystyrene-block-poly(2-hydroxyethyl methacrylate-ran-2-(succinyloxy)ethyl methacrylate) (PS-b-P(HEMA-r-SEMA)) having random –OH and –COOH groups along the pore walls prepared by a method which combines solvent induced self-assembly of the block copolymer and nonsolvent induced phase separation (SNIPS). The membrane consists of soft isoporous channels due to swelling of the P(HEMA-r-SEMA) blocks in a hydrated state. The effective pore size of the membrane in a hydrated state is significantly lower compared to that in a dry state. These soft channels allow the permeation of BSA while retaining Hb at constant pH 7.4 where both proteins are negatively charged. In comparison to 22 commercial and in-house prepared membranes the PS-b-P(HEMA-r-SEMA) membrane presents unprecedented ideal selectivity of BSA over Hb ( ψ B S A / H b = 16 ). Unlike the conventional technique in this case the electroneutrality of one protein is not mandatory which will provide significantly easier handling.

中文翻译：

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牛血清白蛋白选择性整合不对称等孔膜

摘要 牛血清白蛋白 (BSA) 和血红蛋白 (Hb) 这两种分子量几乎相同的蛋白质的分离已成为二十多年来的一大挑战。使用传统的超滤膜分离这些蛋白质只能在一种蛋白质的等电点通过膜和另一种蛋白质之间的静电斥力进行分离。在这里，我们介绍了一种由聚苯乙烯-嵌段-聚（2-羟乙基甲基丙烯酸酯-ran-2-（琥珀酰氧基）乙基甲基丙烯酸酯）（PS-bP（HEMA-r-SEMA））制成的具有随机-OH和-COOH基团的整体不对称等孔膜通过将嵌段共聚物的溶剂诱导自组装和非溶剂诱导相分离 (SNIPS) 相结合的方法制备的孔壁。由于 P(HEMA-r-SEMA) 块在水合状态下膨胀，膜由柔软的等孔通道组成。与干燥状态相比，水合状态下膜的有效孔径显着降低。这些软通道允许 BSA 渗透，同时将 Hb 保持在恒定的 pH 值 7.4，其中两种蛋白质都带负电荷。与 22 种商业和内部制备的膜相比，PS-bP(HEMA-r-SEMA) 膜表现出前所未有的 BSA 对 Hb 的理想选择性（ψ BSA / H b = 16）。与这种情况下的传统技术不同，一种蛋白质的电中性不是强制性的，这将提供明显更容易的处理。这些软通道允许 BSA 渗透，同时将 Hb 保持在恒定的 pH 值 7.4，其中两种蛋白质都带负电荷。与 22 种商业和内部制备的膜相比，PS-bP(HEMA-r-SEMA) 膜表现出前所未有的 BSA 对 Hb 的理想选择性（ψ BSA / H b = 16）。与这种情况下的传统技术不同，一种蛋白质的电中性不是强制性的，这将提供明显更容易的处理。这些软通道允许 BSA 渗透，同时将 Hb 保持在恒定的 pH 值 7.4，其中两种蛋白质都带负电荷。与 22 种商业和内部制备的膜相比，PS-bP(HEMA-r-SEMA) 膜表现出前所未有的 BSA 对 Hb 的理想选择性（ψ BSA / H b = 16）。与这种情况下的传统技术不同，一种蛋白质的电中性不是强制性的，这将提供明显更容易的处理。