Pappas Harry C, Phan Samantha, Yoon Suhyun, Edens Lance E, Meng Xiangli, Schanze Kirk S, Whitten David G, Keller David J
Department of Nanoscience and Microsystems Engineering, University of New Mexico , Albuquerque, New Mexico 87131-1341, United States.
Center for Biomedical Engineering, Department of Chemical and Biological Engineering, University of New Mexico , Albuquerque, New Mexico 87131-1341, United States.
ACS Appl Mater Interfaces. 2015 Dec 23;7(50):27632-8. doi: 10.1021/acsami.5b06852. Epub 2015 Dec 8.
Mitigation of bacterial adhesion and subsequent biofilm formation is quickly becoming a strategy for the prevention of hospital-acquired infections. We demonstrate a basic strategy for surface modification that combines the ability to control attachment by microbes with the ability to inactivate microbes. The surface consists of two active materials: poly(p-phenylene ethynylene)-based polymers, which can inactivate a wide range of microbes and pathogens, and poly(N-isopropylacrylamide)-based polymers, which can switch between an hydrophobic "capture" state and a hydrophilic "release" state. The combination of these materials creates a surface that can both bind microbes in a switchable way and kill surface-bound microbes efficiently. Considerable earlier work with cationic poly(p-phenylene ethynylene) polyelectrolytes has demonstrated and characterized their antimicrobial properties, including the ability to efficiently destroy or deactivate Gram-negative and Gram-positive bacteria, fungi, and viruses. Similarly, much work has shown (1) that surface-polymerized films of poly(N-isopropylacrylamide) are able to switch their surface thermodynamic properties from a swollen, relatively hydrophilic state at low temperature to a condensed, relatively hydrophobic state at higher temperature, and (2) that this switch can control the binding and/or release of microbes to poly(N-isopropylacrylamide) surfaces. The active surfaces described herein were fabricated by first creating a film of biocidal poly(p-phenylene ethynylene) using layer-by-layer methods, and then conferring switchable adhesion by growing poly(N-isopropylacrylamide) through the poly(p-phenylene ethynylene) layer, using surface-attached polymerization initiators. The resulting multifunctional, complex films were then characterized both physically and functionally. We demonstrate that such films kill and subsequently induce widespread release of Gram-negative and Gram-positive bacteria.
减轻细菌粘附及随后的生物膜形成正迅速成为预防医院获得性感染的一种策略。我们展示了一种表面改性的基本策略，该策略将控制微生物附着的能力与使微生物失活的能力结合起来。该表面由两种活性材料组成：基于聚对苯撑乙炔的聚合物，它能使多种微生物和病原体失活；以及基于聚N-异丙基丙烯酰胺的聚合物，它能在疏水的“捕获”状态和亲水的“释放”状态之间切换。这些材料的组合创造了一种既能以可切换的方式结合微生物又能有效杀死表面结合微生物的表面。早期大量关于阳离子聚对苯撑乙炔聚电解质的工作已经证明并表征了它们的抗菌特性，包括有效破坏或使革兰氏阴性菌、革兰氏阳性菌、真菌和病毒失活的能力。同样，许多工作表明：（1）聚N-异丙基丙烯酰胺的表面聚合膜能够将其表面热力学性质从低温下的膨胀、相对亲水状态转变为高温下的凝聚、相对疏水状态；（2）这种转变可以控制微生物与聚N-异丙基丙烯酰胺表面的结合和/或释放。本文所述的活性表面是通过首先使用逐层方法制备一层杀菌性聚对苯撑乙炔薄膜，然后利用表面附着的聚合引发剂使聚N-异丙基丙烯酰胺穿过聚对苯撑乙炔层生长，从而赋予其可切换的粘附性来制备的。然后对所得的多功能复合薄膜进行了物理和功能表征。我们证明了这种薄膜能够杀死革兰氏阴性菌和革兰氏阳性菌，并随后诱导它们大量释放。
