title: Highly Stable, Protein-Resistant Surfaces via the Layer-by-Layer Assembly of Poly(sulfobetaine methacrylate) and Tannic Acid.
abstract: 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.
authors.affiliation: †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.
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Ren
authors.affiliation: †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.
authors.forename: Hao-Cheng
authors.initials: HC
authors.lastname: Yang
authors.affiliation: †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.
authors.forename: Hong-Qing
authors.initials: HQ
authors.lastname: Liang
authors.affiliation: †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.
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Xu
authors.affiliation: †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.
authors.forename: Ling-Shu
authors.initials: LS
authors.lastname: Wan
authors.affiliation: †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.
authors.forename: Zhi-Kang
authors.initials: ZK
authors.lastname: Xu
mesh_terms: D000327:Adsorption; D001672:Biocompatible Materials / Q000737:chemistry; D006454:Hemoglobins / Q000737:chemistry; D008689:Methacrylates / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D009113:Muramidase / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D058525:Quartz Crystal Microbalance Techniques; D012710:Serum Albumin, Bovine / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013634:Tannins / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D006454:Hemoglobins; D008689:Methacrylates; D013634:Tannins; C521589:sulfobetaine methacrylate polymer; D012710:Serum Albumin, Bovine; D009113:Muramidase