Temporal Control of Gelation and Polymerization Fronts Driven by an Autocatalytic Enzyme Reaction.
Temporal Control of Gelation and Polymerization Fronts Driven by an Autocatalytic Enzyme Reaction.
复制标题
DOI：
10.1002/anie.201510604
复制
发表时间：
2016-02-05
期刊：
影响因子：
--
通讯作者：
Pojman JA
中科院分区：
文献类型：
--
作者：
Jee E;Bánsági T Jr;Taylor AF;Pojman JA
化学系统在激活之前保持动力学休眠，在材料科学中有许多应用。在此，我们提出了一种利用内置开关控制凝胶化的方法：在脲酶催化的尿素水解诱导期后pH值的增加被用来触发碱催化的Michael将水溶性三硫醇加成到聚乙二醇二丙烯酸酯中。凝胶化的时间（分钟到小时）要么通过初始浓度预先设定，要么由碱在局部引发反应，从而导致聚合前沿，将混合物从液体转化为凝胶（约0.1 mm min - 1）。水凝胶的水解降解速率取决于初始浓度，从而导致凝胶寿命从数小时到数月不等。通过这种方式，利用自催化酶反应的输出来驱动水凝胶的聚合和随后的降解，在温和的条件下，凝胶的时间编程是可能的。
Chemical systems that remain kinetically dormant until activated have numerous applications in materials science. Herein we present a method for the control of gelation that exploits an inbuilt switch: the increase in pH after an induction period in the urease‐catalyzed hydrolysis of urea was used to trigger the base‐catalyzed Michael addition of a water‐soluble trithiol to a polyethylene glycol diacrylate. The time to gelation (minutes to hours) was either preset through the initial concentrations or the reaction was initiated locally by a base, thus resulting in polymerization fronts that converted the mixture from a liquid into a gel (ca. 0.1 mm min−1). The rate of hydrolytic degradation of the hydrogel depended on the initial concentrations, thus resulting in a gel lifetime of hours to months. In this way, temporal programming of gelation was possible under mild conditions by using the output of an autocatalytic enzyme reaction to drive both the polymerization and subsequent degradation of a hydrogel.