Bioactive Polymer Synthesis and Surface Engineering Group, Department of Microsystems Engineering (IMTEK) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) , Albert-Ludwigs-Universität Freiburg , Georges-Köhler-Allee 105 , 79110 Freiburg , Germany.
Laboratory for Process Technology, Department of Microsystem Engineering (IMTEK) , Albert-Ludwigs-Universität Freiburg , Georges-Köhler-Allee 103 , 79110 Freiburg , Germany.
Langmuir. 2019 Feb 5;35(5):1211-1226. doi: 10.1021/acs.langmuir.8b03410. Epub 2019 Jan 9.
Biofilm-associated infections of medical devices are a global problem. For the prevention of such infections, biomaterial surfaces are chemically or topographically modified to slow down the initial stages of biofilm formation. In the bifunctional material here presented, chemical and topographical cues are combined, so that protein and bacterial adhesion as well as bacterial proliferation are effectively inhibited. Upon changes in the surface topography parameters and investigation of the effect of these changes on bioactivity, structure-property relationships are obtained. The target material is obtained by microcontact printing (μCP), a soft lithography method. The antimicrobial component, poly(oxanorbornene)-based synthetic mimics of an antimicrobial peptide (SMAMP), was printed onto a protein-repellent polysulfobetaine hydrogel, so that bifunctional 3D structured polymer surfaces with 1, 2, and 8.5 μm spacing are obtained. These surfaces are characterized with fluorescence microscopy, surface plasmon resonance spectroscopy, atomic force microscopy, and contact angle measurements. Biological studies show that the bifunctional surfaces with 1 and 2 μm spacing are 100% antimicrobially active against Escherichia coli and Staphylococcus aureus, 100% fibrinogen-repellent, and nontoxic to human gingival mucosal keratinocytes. At 8.5 μm spacing, the broad-band antimicrobial activity and the protein repellency are compromised, which indicates that this spacing is above the upper limit for effective simultaneous antimicrobial activity and protein repellency of polyzwitterionic-polycationic materials.
医疗器械相关的生物膜感染是一个全球性的问题。为了预防此类感染，生物材料表面经过化学或形貌修饰以减缓生物膜形成的初始阶段。在本研究中所提出的双功能材料中，化学和形貌线索相结合，从而有效抑制蛋白和细菌的黏附以及细菌的增殖。通过改变表面形貌参数并研究这些变化对生物活性的影响，获得了结构-性能关系。目标材料通过微接触印刷（μCP）获得，这是一种软光刻方法。将具有抗菌活性的聚（降冰片烯）基合成抗菌肽模拟物（SMAMP）印刷到蛋白质排斥性聚磺酸甜水凝胶上，从而获得具有 1、2 和 8.5 μm 间距的双功能 3D 结构化聚合物表面。这些表面通过荧光显微镜、表面等离子体共振光谱、原子力显微镜和接触角测量进行了表征。生物学研究表明，具有 1 和 2 μm 间距的双功能表面对大肠杆菌和金黄色葡萄球菌具有 100%的抗菌活性，100%排斥纤维蛋白原，且对人牙龈黏膜角质细胞无毒。在 8.5 μm 的间距下，广谱抗菌活性和蛋白质排斥性降低，这表明该间距高于聚两性离子-聚阳离子材料有效同时具有抗菌活性和蛋白质排斥性的上限。
