Ni Jiaying, Wan Yuting, Cai Ying, Ding Peng, Cohen Stuart Martien A, Wang Junyou
Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, People's Republic of China.
Langmuir. 2022 Mar 15;38(10):3234-3243. doi: 10.1021/acs.langmuir.1c03325. Epub 2022 Feb 25.
Polyelectrolyte nanogels containing cross-linked ionic polymer networks feature both soft environment and intrinsic charges which are of great potential for enzyme encapsulation. In this work, well-defined poly(acrylic acid) (PAA) nanogels have been synthesized based on a facile strategy, namely, electrostatic assembly directed polymerization (EADP). Specifically, AA monomers are polymerized together with a cross-linker in the presence of a cationic-neutral diblock copolymer as the template. Effects of control factors including pH, salt concentration, and cross-linking degree have been investigated systematically, based on which the optimal preparation of PAA nanogels has been established. The obtained nanogel features not only compatible pocket for safely loading enzymes without disturbing their structures, but also abundant negative charges which enable selective and efficient encapsulation of cationic enzymes. The loading capacities of PAA nanogels for cytochrome (cyt ) and lysozyme are 100 and 125 μg/mg (enzyme/nanogel), respectively. More notably, the PAA network seems to modulate a favorable microenvironment for cyt and induces 2-fold enhanced activity for the encapsulated enzymes, as indicated by the steady-state kinetic assay. Our study reveals the control factors of EADP for optimal synthesis of anionic nanogels and validates their distinctive advances with respect to efficient loading and activation of cationic enzymes.
含有交联离子聚合物网络的聚电解质纳米凝胶具有柔软的环境和固有电荷，在酶包封方面具有巨大潜力。在这项工作中，基于一种简便的策略，即静电组装定向聚合（EADP），合成了结构明确的聚（丙烯酸）（PAA）纳米凝胶。具体而言，丙烯酸（AA）单体在阳离子-中性二嵌段共聚物作为模板的存在下与交联剂一起聚合。系统研究了包括pH值、盐浓度和交联度在内的控制因素的影响，并在此基础上确定了PAA纳米凝胶的最佳制备方法。所获得的纳米凝胶不仅具有兼容的口袋，可安全地装载酶而不干扰其结构，而且具有丰富的负电荷，能够选择性和高效地包封阳离子酶。PAA纳米凝胶对细胞色素（cyt）和溶菌酶的负载量分别为100和125μg/mg（酶/纳米凝胶）。更值得注意的是，如稳态动力学分析所示，PAA网络似乎为细胞色素营造了一个有利的微环境，并使包封酶的活性提高了2倍。我们的研究揭示了EADP用于阴离子纳米凝胶最佳合成的控制因素，并验证了它们在有效负载和激活阳离子酶方面的独特优势。
