Ren Peng-Fei, Yang Hao-Cheng, Liang Hong-Qing, Xu Xiao-Ling, Wan Ling-Shu, Xu Zhi-Kang
†Ministry of Education (MOE) Key Laboratory of Macromolecular Synthesis and Functionalization, Joint Laboratory for Adsorption and Separation Materials, Department of Polymer Science and Engineering, and ‡Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, People's Republic of China.
Langmuir. 2015 Jun 2;31(21):5851-8. doi: 10.1021/acs.langmuir.5b00920. Epub 2015 May 20.
Zwitterionic materials have received great attention because of the non-fouling property. As a result of the electric neutrality of zwitterionic polymers, their layer-by-layer (LBL) assembly is generally conducted under specific conditions, such as very low pH values or ionic strength. The formed multilayers are unstable at high pH or in a high ionic strength environment. Therefore, the formation of highly stable multilayers of zwitterionic polymers via the LBL assembly process is still challenging. Here, we report the LBL assembly of poly(sulfobetaine methacrylate) (PSBMA) with a polyphenol, tannic acid (TA), for protein-resistant surfaces. The assembly process was monitored by a quartz crystal microbalance (QCM) and variable-angle spectroscopic ellipsometry (VASE), which confirms the formation of thin multilayer films. We found that the (TA/PSBMA)n multilayers are stable over a wide pH range of 4-10 and in saline, such as 1 M NaCl or urea solution. The surface morphology and chemical composition were characterized by specular reflectance Fourier transform infrared spectroscopy (FTIR/SR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Furthermore, (TA/PSBMA)n multilayers show high hydrophilicity, with a water contact angle lower than 15°. A QCM was used to record the dynamic protein adsorption process. Adsorption amounts of bovine serum albumin (BSA), lysozyme (Lys), and hemoglobin (Hgb) on (TA/PSBMA)20 multilayers decreased to 0.42, 52.9, and 37.9 ng/cm(2) from 328, 357, and 509 ng/cm(2) on a bare gold chip surface, respectively. In addition, the protein-resistance property depends upon the outmost layer. This work provides new insights into the LBL assembly of zwitterionic polymers.
两性离子材料因其抗污性能而备受关注。由于两性离子聚合物呈电中性，其逐层（LBL）组装通常在特定条件下进行，如极低的pH值或离子强度。所形成的多层膜在高pH值或高离子强度环境下不稳定。因此，通过LBL组装过程形成高度稳定的两性离子聚合物多层膜仍然具有挑战性。在此，我们报道了聚（甲基丙烯酸磺酸甜菜碱）（PSBMA）与一种多酚——单宁酸（TA）用于抗蛋白质表面的LBL组装。组装过程通过石英晶体微天平（QCM）和可变角度光谱椭偏仪（VASE）进行监测，这证实了薄多层膜的形成。我们发现（TA/PSBMA）n多层膜在4 - 10的宽pH范围内以及在盐水（如1 M NaCl或尿素溶液）中都很稳定。通过镜面反射傅里叶变换红外光谱（FTIR/SR）、X射线光电子能谱（XPS）和原子力显微镜（AFM）对表面形貌和化学成分进行了表征。此外，（TA/PSBMA）n多层膜具有高亲水性，水接触角低于15°。使用QCM记录动态蛋白质吸附过程。牛血清白蛋白（BSA）、溶菌酶（Lys）和血红蛋白（Hgb）在（TA/PSBMA）20多层膜上的吸附量分别从裸金芯片表面的328、357和509 ng/cm²降至0.42、52.9和37.9 ng/cm²。此外，抗蛋白质性能取决于最外层。这项工作为两性离子聚合物的LBL组装提供了新的见解。
