Protein Adsorption on Grafted Zwitterionic Polymers Depends on Chain Density and Molecular Weight
Protein Adsorption on Grafted Zwitterionic Polymers Depends on Chain Density and Molecular Weight
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DOI：
10.1002/adfm.202000757
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发表时间：
2020-06-02
影响因子：
19
通讯作者：
Leckband, Deborah E.
中科院分区：
文献类型：
--
作者：
Ahmed, Syeda Tajin;Leckband, Deborah E.
这项研究表明，蛋白质吸附端接枝，两性离子聚（磺基甜菜碱）（pSBMA）薄膜取决于接枝密度，分子量和离子强度。两性离子聚合物表现出超低的非特异性污染（蛋白质吸附）和优异的生物相容性。这张照片与最近的报道形成对比，可溶性pSBMA链结合蛋白质并改变蛋白质折叠稳定性。为了解决这一明显的矛盾，蛋白质吸附的链接枝参数的依赖性进行了研究：即，接枝密度，分子量和离子强度。研究比较了磷酸甘油酸激酶和带正电荷的溶菌酶的吸附与缩放的接枝参数s/2R（F），其中s是接枝位点之间的距离，R-F是Flory半径。吸附蛋白量与s/2R（F）的关系曲线呈钟形，在s/2R（F）附近的最大值接近1，且振幅随离子强度而减小。这种行为是定性的胶体相互作用与弱吸引力，接枝链的理论模型相一致。结果证实，蛋白质吸附pSBMA薄膜，他们提出了一个潜在的机制。与聚合物模型的比较进一步确定了有效排斥蛋白质的pSBMA膜的设计规则。
This study demonstrates that protein adsorption on end-grafted, zwitterionic poly(sulfobetaine) (pSBMA) thin films depends on the grafting density, molecular weight, and ionic strength. Zwitterionic polymers exhibit ultralow nonspecific fouling (protein adsorption) and excellent biocompatibility. This picture contrasts with a recent report that soluble pSBMA chains bind proteins and alter the protein folding stability. To address this apparent contradiction, the dependence of protein adsorption on the chain grafting parameters is investigated: namely, the grafting density, molecular weight, and ionic strength. Studies compared the adsorption of phosphoglycerate kinase and positively charged lysozyme versus the scaled grafting parameter s/2R(F), where s is the distance between grafting sites and R-F is the Flory radius. Plots of the adsorbed protein amount versus s/2R(F) exhibit a bell-shaped curve, with a maximum near s/2R(F) approximate to 1 and an amplitude that decreases with ionic strength. This behavior is qualitatively consistent with theoretical models for colloid interactions with weakly attractive, grafted chains. The results confirm that proteins do adsorb to pSBMA thin films, and they suggest an underlying mechanism. Comparisons with polymer models further identify design rules for pSBMA films that effectively repel protein.