Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan 48109, United States.
Langmuir. 2011 Apr 5;27(7):4010-9. doi: 10.1021/la1046904. Epub 2011 Mar 10.
A new strategy for preparing antimicrobial surfaces by a simple dip-coating procedure is reported. Amphiphilic polycations with different mole ratios of monomers containing dodecyl quaternary ammonium, methoxyethyl, and catechol groups were synthesized by free-radical polymerization. The polymer coatings were prepared by immersing glass slides into a polymer solution and subsequent drying and heating. The quaternary ammonium side chains endow the coatings with potent antibacterial activity, the methoxyethyl side chains enable tuning the hydrophobic/hydrophilic balance, and the catachol groups promote immobilization of the polymers into films. The polymer-coated surfaces displayed bactericidal activity against Escherichia coli and Staphylococcus aureus in a dynamic contact assay and prevented the accumulation of viable E. coli, S. aureus, and Acinetobacter baumannii for up to 96 h. Atomic force microscopy (AFM) images of coating surfaces indicated that the surfaces exhibit virtually the same smoothness for all polymers except the most hydrophobic. The hydrophobic polymer without methoxyethyl side chains showed clear structuring into polymer domains, causing high surface roughness. Sum-frequency generation (SFG) vibrational spectroscopy characterization of the surface structures demonstrated that the dodecyl chains are predominantly localized at the surface-air interface of the coatings. SFG also showed that the phenyl groups of the catechols are oriented on the substrate surface. These results support our hypothesis that the adhesive or cross-linking functionality of catechol groups discourages polymer leaching, allowing the tuning of the amphiphilic balance by incorporating hydrophilic components into the polymer chains to gain potent biocidal activity.
本文报道了一种通过简单浸涂法制备抗菌表面的新策略。通过自由基聚合合成了具有不同单体摩尔比的含十二烷基季铵、甲氧基乙基和儿茶酚基团的两亲性聚阳离子。将聚合物涂层通过将玻璃载玻片浸入聚合物溶液中，然后干燥和加热来制备。季铵侧链赋予涂层强大的抗菌活性，甲氧基乙基侧链能够调节疏水性/亲水性平衡，儿茶酚基团促进聚合物固定在薄膜中。在动态接触试验中，聚合物涂层表面对大肠杆菌和金黄色葡萄球菌表现出杀菌活性，并能防止大肠杆菌、金黄色葡萄球菌和鲍曼不动杆菌的存活长达 96 小时。涂层表面的原子力显微镜 (AFM) 图像表明，除了最疏水的聚合物外，所有聚合物的表面都几乎具有相同的光滑度。没有甲氧基乙基侧链的疏水性聚合物明显形成聚合物畴，导致表面粗糙度增加。表面结构的和频产生 (SFG) 振动光谱表征表明，十二烷基链主要位于涂层的表面-空气界面处。SFG 还表明，儿茶酚的苯基基团在基底表面上取向。这些结果支持我们的假设，即儿茶酚基团的粘附或交联功能阻止了聚合物的浸出，通过将亲水性成分掺入聚合物链中，从而获得强大的杀菌活性，来调节两亲平衡。
