Controlled and tunable design of polymer interface for immobilization of enzymes: does curvature matter?
Controlled and tunable design of polymer interface for immobilization of enzymes: does curvature matter?
复制标题
DOI：
10.1039/c6sm02380k
复制
发表时间：
2017-02-07
期刊：
影响因子：
3.4
通讯作者：
Synytska, Alla
中科院分区：
文献类型：
--
作者：
Marschelke, Claudia;Raguzin, Ivan;Synytska, Alla
表面性能的控制和调整是材料程序化和合理设计的必要条件。特别是，聚合物电刷改性胶体可以用作酶固定化的载体材料。虽然控制毛刷结构至关重要，但关于接枝密度对设计界面性能的影响以及对生物分子固定化的影响，目前还缺乏系统的研究。在这项工作中，我们研究了不同接枝密度的聚合物刷的表面性能，通过改变引发基团的密度，使用“从”方法在平面和胶体颗粒基质上制备了不同接枝密度的聚合物刷。通过这种方法，我们可以控制和调节载体材料的界面性质，如膨胀、电荷、粘附以及漆酶在接枝的聚电解质层上的吸附。我们表明，对于依赖接枝密度的膨胀行为，从平面基底到弯曲基底的结果没有直接的可转移性。在平面和弯曲颗粒基板上，PDMAEMA层的最大膨胀度分别在接枝密度为0.34 nm（-2）和0.1 nm（-2）时达到。接枝密度对聚合物层在两种基材上的粘附性能也有很大的影响，即接枝密度的降低会导致从粘附状态到非粘附状态的转变。低温透射电镜（cro - tem）和原子力显微镜（AFM）力距测量结果表明，固定化墨苔菌漆酶可以减少聚合物的溶胀，从而导致最终聚合物-酶层的表面形态、电荷和粘附性能发生变化。此外，在中等嫁接密度下，漆酶的效率和活性更高，似乎优于最大刷密度。
Control and tuning of surface properties is indispensable for the programmed and rational design of materials. Particularly, polymeric brush-modified colloids can be used as carrier materials for enzyme immobilization. Although it is of prime importance to control the brush architecture, there is still a lack of systematic investigations concerning the impact of grafting density on the properties of the designed interface, as well as on the immobilization of biomolecules. In this work, we investigate the surface properties of polymer brushes with different grafting densities prepared using a "grafting from'' approach on flat and on colloidal particle substrates by varying the density of initiator groups. In this way, we control and tune interfacial properties of the carrier material such as swelling, charge, adhesion as well as adsorption of laccase from Trametes versicolor on the grafted polyelectrolyte layer. We show that there is no direct transferability of the results received from planar to curved substrates regarding the swelling behavior in dependence on the grafting density. The maximum of swelling degree of PDMAEMA layers is achieved at 0.34 nm(-2) and at 0.1 nm(-2) grafting density for planar and curved particle substrates, respectively. The adhesion properties of the polymeric layer on both substrates are also strongly influenced by the grafting density, i.e. a decrease of the grafting density causes a transition from the adhesive to non-adhesive state. As proven by the cryo-TEM and AFM force distance measurements, an immobilization of laccase from Trametes versicolor causes a decrease of the polymer swelling and therefore leads to the changes in the surface morphology, charge and adhesion performance of final polymer-enzyme layer. Moreover, the higher effectiveness and activity of laccase were observed for the intermediate grafting densities which seem to be preferable over the maximum brush densities.