Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.
Acta Biomater. 2013 Apr;9(4):6236-44. doi: 10.1016/j.actbio.2012.11.026. Epub 2012 Dec 2.
Three protease-resistant bioorganic 304 stainless steel surfaces were created through the reaction of synthetic peptides consisting of the D-enantiomeric isomer (D-K122-4), the retro-inverso D-enantiomeric isomer (RI-K122-4), and a combination of the two peptides (D+RI) of the Pseudomonas aeruginosa PilA receptor binding domain with steel surfaces. The peptides used to produce the new materials differ only in handedness of their three-dimensional structure, but they reacted with the steel to yield materials that differed in their surface electron work function (EWF) while displaying an identical chemical composition and equivalent surface adhesive force properties. These surfaces allowed for an assessment of the relative role of surface EWF in initial biofilm formation. We examined the ability of various bacteria (selected strains of Listeria monocytogenes, L. innocua, Staphylococcus aureus and S. epidermidis) to initiate biofilm formation. The D-K1224 generated surface displayed the lowest EWF (classically associated with greater molecular interactions and more extensive biofilm formation) but was observed to be least effectively colonized by bacteria (>50% decrease in bacterial adherence of all strains). The highest surface EWF with the lowest surface free energy (RI-K122-4 generated) was more extensively colonized by bacteria, with the binding of some strains being equivalent to unmodified steel. The D+RI generated surface was least effective in minimizing biofilm formation, where some strains displayed enhanced bacterial colonization. Fluorescent microscopy revealed that the D and RI peptides displayed similar but clearly different binding patterns, suggesting that the peptides recognized different sites on the steel, and that differential binding of the peptides to the steel surfaces influences the binding of different bacterial strains and species. We have demonstrated that stainless steel surfaces can be easily modified by peptides to generate surfaces with new physiochemical properties. The D-K122-4-modified surface substantially decreases biofilm formation compared to the RI-K122-4 and D+RI surfaces.
通过将含有铜绿假单胞菌 PilA 受体结合域的 D-对映异构体 (D-K122-4)、反向 D-对映异构体 (RI-K122-4) 以及这两种肽的混合物 (D+RI) 的合成肽与不锈钢表面反应，制备了三种耐蛋白酶的生物有机 304 不锈钢表面。用于制备新材料的肽仅在其三维结构的手性上有所不同，但它们与钢反应生成的材料在表面电子功函数 (EWF) 上有所不同，同时显示出相同的化学成分和等效的表面粘附力特性。这些表面允许评估表面 EWF 在初始生物膜形成中的相对作用。我们研究了各种细菌（单核细胞增生李斯特菌、无害李斯特菌、金黄色葡萄球菌和表皮葡萄球菌的选定菌株）形成生物膜的能力。D-K1224 生成的表面显示出最低的 EWF（通常与更大的分子相互作用和更广泛的生物膜形成相关），但观察到其被细菌定植的效果最差（所有菌株的细菌粘附减少超过 50%）。具有最低表面自由能（RI-K122-4 生成）和最高表面 EWF 的表面被细菌更广泛地定植，一些菌株的结合相当于未修饰的钢。D+RI 生成的表面在最大限度地减少生物膜形成方面效果最差，一些菌株显示出增强的细菌定植。荧光显微镜显示，D 和 RI 肽显示出相似但明显不同的结合模式，表明肽识别钢表面的不同部位，并且肽对钢表面的不同结合影响不同细菌菌株和物种的结合。我们已经证明，不锈钢表面可以很容易地通过肽进行修饰，以生成具有新物理化学性质的表面。与 RI-K122-4 和 D+RI 表面相比，D-K122-4 修饰的表面大大减少了生物膜的形成。
