Kurowska Monika, Widyaya Vania Tanda, Al-Ahmad Ali, Lienkamp Karen
Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) and Department of Microsystems Engineering (IMTEK), Albert-Ludwigs-Universität, Georges-Köhler-Allee 105, 79110 Freiburg, Germany.
Materials (Basel). 2018 Aug 11;11(8):1411. doi: 10.3390/ma11081411.
By copolymerizing an amphiphilic oxanorbornene monomer bearing N- tert-butyloxycarbonyl (Boc) protected cationic groups with an oxanorbornene-functionalized poly(ethylene glycol) (PEG) macromonomer, bifunctional comb copolymers were obtained. Varying the comonomer ratios led to copolymers with PEG contents between 5⁻25 mol %. These polymers were simultaneously surface-immobilized on benzophenone-bearing substrates and cross-linked with pentaerythritoltetrakis(3-mercaptopropionate). They were then immersed into HCl to remove the Boc groups. The thus obtained surface-attached polymer hydrogels (called SMAMP*--PEG) were simultaneously antimicrobial and protein-repellent. Physical characterization data showed that the substrates used were homogeneously covered with the SMAMP*--PEG polymer, and that the PEG moieties tended to segregate to the polymer⁻air interface. Thus, with increasing PEG content, the interface became increasingly hydrophilic and protein-repellent, as demonstrated by a protein adhesion assay. With 25 mol % PEG, near-quantitative protein-adhesion was observed. The antimicrobial activity of the SMAMP*--PEG polymers originates from the electrostatic interaction of the cationic groups with the negatively charged cell envelope of the bacteria. However, the SMAMP*--PEG surfaces were only fully active against , while their activity against was already compromised by as little as 5 mol % (18.8 mass %) PEG. The long PEG chains seem to prevent the close interaction of bacteria with the surface, and also might reduce the surface charge density.
通过将带有N-叔丁氧羰基（Boc）保护的阳离子基团的两亲性氧杂降冰片烯单体与氧杂降冰片烯官能化的聚乙二醇（PEG）大分子单体共聚，获得了双功能梳状共聚物。改变共聚单体比例可得到PEG含量在5⁻25摩尔%之间的共聚物。这些聚合物同时表面固定在含二苯甲酮的底物上，并与季戊四醇四（3-巯基丙酸酯）交联。然后将它们浸入HCl中以除去Boc基团。由此获得的表面附着的聚合物水凝胶（称为SMAMP*--PEG）同时具有抗菌和抗蛋白性能。物理表征数据表明，所用底物被SMAMP*--PEG聚合物均匀覆盖，并且PEG部分倾向于聚集到聚合物-空气界面。因此，如蛋白质粘附试验所示，随着PEG含量的增加，界面变得越来越亲水且具有抗蛋白性能。当PEG含量为25摩尔%时，观察到近乎定量的蛋白质粘附。SMAMP*--PEG聚合物的抗菌活性源于阳离子基团与细菌带负电荷的细胞膜的静电相互作用。然而，SMAMP*--PEG表面仅对[具体细菌名称1]完全有活性，而其对[具体细菌名称2]的活性在PEG含量低至5摩尔%（18.8质量%）时就已受到损害。长PEG链似乎阻止了细菌与表面的紧密相互作用，并且也可能降低了表面电荷密度。
