Reversible Bacterial Adhesion on Mixed Poly(dimethylaminoethyl methacrylate)/Poly(acrylamidophenyl boronic acid) Brush Surfaces

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• 作者：Xinhong Xiong ; Zhaoqiang Wu ; Qian Yu ; Lulu Xue ; Jun Du ; Hong Chen
• 刊名：Langmuir
• 出版年：2015
• 出版时间：November 10, 2015
• 年：2015
• 卷：31
• 期：44
• 页码：12054-12060
• 全文大小：463K
• ISSN：1520-5827

文摘

A simple and versatile method for the preparation of surfaces to control bacterial adhesion is described. Substrates were first treated with two catechol-based polymerization initiators, one for thermal initiation and one for visible-light photoinitiation. Graft polymerization in sequence of dimethylaminoethyl methacrylate (DMAEMA) and 3-acrylamidebenzene boronic acid (BA) from the surface-bound initiators to form mixed polymer brushes on the substrate was then carried out. The PDMAEMA grafts were thermally initiated and the PBA grafts were visible-light-photoinitiated. Gold, poly(vinyl chloride) (PVC), and poly(dimethylsiloxane) (PDMS) were used as model substrates. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), and ellipsometry analysis confirmed the successful grafting of PDMAEMA/PBA mixed brushes. We demonstrated that the resulting surfaces showed charge-reversal properties in response to change of pH. The transition in surface charge at a specific pH allowed the surface to be reversibly switched from bacteria-adhesive to bacteria-resistant. At pH 4.5, below the isoelectric points (IEP, pH 5.3) of the mixed brushes, the surfaces are positively charged and the negatively charged Gram-positive S. aureus adheres at high density (2.6 脳 10⁶ cells/cm²) due to attractive electrostatic interactions. Subsequently, upon increasing the pH to 9.0 to give negatively charged polymer brush surface, 鈭?0% of the adherent bacteria are released from the surface, presumably due to repulsive electrostatic interactions. This approach provides a simple method for the preparation of surfaces on which bacterial adhesion can be controlled and is applicable to a wide variety of substrates.