Department of Chemistry, Bogazici University , Bebek, Istanbul 34342, Turkey.
Center for Life Sciences and Technologies, Bogazici University , Bebek, Istanbul 34342, Turkey.
ACS Appl Mater Interfaces. 2017 Aug 23;9(33):27946-27954. doi: 10.1021/acsami.7b07779. Epub 2017 Aug 8.
Fabrication of antibiofouling, specifically reactive polymeric coatings that undergo facile functionalization with thiol-bearing small molecules and ligands, yields effective platforms for biomolecular immobilization and sensing. Poly(ethylene glycol) (PEG)-based copolymers containing alkoxysilyl groups to enable surface-anchoring and furan-protected maleimide groups as latent thiol-reactive moieties as side-chains were synthesized. Reactive interfaces were obtained by coating these copolymers onto Si/SiO or glass surfaces and activating the maleimide groups to their thiol-reactive forms via thermal treatment. A series of surfaces modified with copolymers containing varying amounts of maleimide groups were synthesized. Effectiveness of surface modification was probed using Fourier transform infrared spectroscopy, contact angle goniometry, ellipsometry and X-ray photoelectron spectroscopy. Facile surface modification through thiol-maleimide conjugation was established by attachment of a thiol-containing fluorescent dye, namely BODIPY-SH. It was demonstrated that these surfaces allow spatially localized modification through microcontact printing. Importantly, the extent of surface modification could be tuned by varying the initial composition of the copolymer used for coating. Using fluorescence microscopy, it was observed that increasing amount of fluorescent dye was attached onto surfaces fabricated with copolymers with increasing amount of masked maleimide groups. Thereafter, the thiol-maleimide conjugation was utilized to decorate these surfaces with biotin, a protein-binding ligand. It was observed that though these biotinylated surfaces were able to bind Streptavidin effectively, some nonspecific binding was observed on places that were not in conformal contact with the stamp during microcontact printing. This nonspecific binding was eliminated upon neutralizing the residual maleimide units on the printed surface using thiol-containing PEG. Notably, fluorescence analysis of Streptavidin immobilized onto biotinylated surfaces fabricated using varying amounts of maleimide demonstrated that the amount of immobilized protein could be tuned by varying surface composition. It can be envisioned that facile fabrication of these maleimide-containing polymeric surfaces, their effective functionalization in a tunable manner to engineer interfaces for effective immobilization or sensing of biomolecules in a spatially controlled manner would make them attractive candidates for various biotechnological applications.
制备具有抗生物污染功能的、可方便地与含巯基小分子和配体进行功能化的反应性聚合涂层，可以得到用于生物分子固定和传感的有效平台。合成了含有烷氧基硅烷基以实现表面锚固和呋喃保护的马来酰亚胺基团作为侧链的潜伏巯基反应性基团的聚（乙二醇）（PEG）共聚物。通过将这些共聚物涂覆到 Si/SiO 或玻璃表面上，并通过热处理将马来酰亚胺基团激活为其巯基反应形式，得到反应性界面。合成了一系列含有不同量马来酰亚胺基团的共聚物修饰的表面。使用傅里叶变换红外光谱、接触角测角法、椭圆光度法和 X 射线光电子能谱法探测表面修饰的有效性。通过将含巯基的荧光染料，即 BODIPY-SH，与马来酰亚胺进行连接，成功地实现了表面的简单修饰。证明这些表面允许通过微接触印刷进行空间局部修饰。重要的是，通过改变用于涂层的共聚物的初始组成，可以调整表面修饰的程度。通过荧光显微镜观察到，附着在含有越来越多掩蔽马来酰亚胺基团的共聚物制备的表面上的荧光染料的量也越来越多。此后，通过将巯基-马来酰亚胺键合用于用生物素修饰这些表面，生物素是一种与蛋白质结合的配体。观察到，虽然这些生物素化表面能够有效地结合链霉亲和素，但在微接触印刷过程中与印版未完全接触的地方观察到一些非特异性结合。通过用含巯基的聚乙二醇中和印刷表面上残留的马来酰亚胺单元，可以消除这种非特异性结合。值得注意的是，通过荧光分析固定在使用不同量马来酰亚胺制备的生物素化表面上的链霉亲和素，表明可以通过改变表面组成来调节固定化蛋白质的量。可以想象，这些含有马来酰亚胺的聚合物表面的简便制备，以及以可调的方式对其进行有效功能化，以工程化用于生物分子有效固定和空间控制传感的界面，将使它们成为各种生物技术应用的有吸引力的候选者。
