美国密歇根大学Zhan Chen团队揭示了基于蛋白质稳定剂TMAO的新型无污染两性离子聚合物的强表面水合作用和抗盐机理。相关研究成果发表在2021年9月28日出版的《美国化学会杂志》。

两性离子聚合物由于其强烈的表面水合作用而表现出优异的防污性能。然而，盐分子可能会严重降低典型两性离子聚合物的表面水合作用，使这些聚合物在实际生物和海洋环境中的应用具有挑战性。最近，基于蛋白质稳定剂三甲胺N-氧化物（TMAO）的新型两性离子聚合物刷被开发为一种优秀的防污染材料。

利用表面敏感和频发生（SFG）振动光谱，研究人员研究了TMAO聚合物刷（pTMAO）的表面水合作用以及盐和蛋白质对表面水合作用的影响。研究发现，暴露于高浓度盐溶液（如海水）只是适度降低表面水合作用。与其他两性离子聚合物相比，其优异的抗盐能力是由于正电荷和负电荷基团之间的距离较短，因此pTMAO中的偶极子较小，TMAO两性离子周围的水合作用较强。同时导致pTMAO中的O^–与水之间的键合相互作用强，并且由于N⁺和水合水的强烈排斥作用，O–与金属阳离子之间的相互作用较弱。

在量子和原子尺度上进行的计算机模拟支持SFG分析结果。除盐效应外，还发现暴露于海水中的蛋白质对pTMAO表面水合作用的影响最小，完全排除了蛋白质附着。pTMAO优异的防污性能源自其极强的表面水合作用，能够有效抵抗盐和蛋白质引起的破坏。

附：英文原文

Title: Strong Surface Hydration and Salt Resistant Mechanism of a New Nonfouling Zwitterionic Polymer Based on Protein Stabilizer TMAO

Author: Hao Huang, Chengcheng Zhang, Ralph Crisci, Tieyi Lu, Hsiang-Chieh Hung, Md Symon Jahan Sajib, Pranab Sarker, Jinrong Ma, Tao Wei, Shaoyi Jiang, Zhan Chen

Issue&Volume: September 28, 2021

Abstract: Zwitterionic polymers exhibit excellent nonfouling performance due to their strong surface hydrations. However, salt molecules may severely reduce the surface hydrations of typical zwitterionic polymers, making the application of these polymers in real biological and marine environments challenging. Recently, a new zwitterionic polymer brush based on the protein stabilizer trimethylamine N-oxide (TMAO) was developed as an outstanding nonfouling material. Using surface-sensitive sum frequency generation (SFG) vibrational spectroscopy, we investigated the surface hydration of TMAO polymer brushes (pTMAO) and the effects of salts and proteins on such surface hydration. It was discovered that exposure to highly concentrated salt solutions such as seawater only moderately reduced surface hydration. This superior resistance to salt effects compared to other zwitterionic polymers is due to the shorter distance between the positively and negatively charged groups, thus a smaller dipole in pTMAO and strong hydration around TMAO zwitterion. This results in strong bonding interactions between the O– in pTMAO and water, and weaker interaction between O– and metal cations due to the strong repulsion from the N+ and hydration water. Computer simulations at quantum and atomistic scales were performed to support SFG analyses. In addition to the salt effect, it was discovered that exposure to proteins in seawater exerted minimal influence on the pTMAO surface hydration, indicating complete exclusion of protein attachment. The excellent nonfouling performance of pTMAO originates from its extremely strong surface hydration that exhibits effective resistance to disruptions induced by salts and proteins.

DOI: 10.1021/jacs.1c08280

Source: https://pubs.acs.org/doi/10.1021/jacs.1c08280