Preparative Macromolecular Chemistry, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstrasse 18, 76128, Karlsruhe, Germany.
Institut für Biologische Grenzflächen, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein, Leopoldshafen, Germany.
Angew Chem Int Ed Engl. 2016 Sep 5;55(37):11276-80. doi: 10.1002/anie.201602894. Epub 2016 Jun 30.
The orthogonal, stepwise, and order-independent unfolding of single-chain nanoparticles (SCNPs) is introduced as a key step towards actively controlling the folding dynamics of SCNPs. The SCNPs are compacted by multiple hydrogen bonds and host-guest interactions. Well-defined diblock (AB) and tetrablock (ABCD) copolymers are equipped with orthogonal recognition motifs via modular ligation along the lateral chain. Initially, single-chain folding of the diblock copolymer was induced by the host-guest complexation of benzo-21-crown-7 (B21C7, host) and a secondary ammonium salt (AS, guest), representing an efficient avenue for single-chain collapse. Next, both orthogonal Hamilton wedge (HW) and cyanuric acid (CA) as well as B21C7-AS motifs were employed to generate SCNPs based on the ABCD polymer system. Subsequently, the stepwise dual-gated and order-independent unfolding of the SCNPs was investigated by the addition of external stimuli. The folding and unfolding were explored by 1D (1) H NMR spectroscopy, dynamic light scattering (DLS), and diffusion-ordered NMR spectroscopy (DOSY).
将单链纳米颗粒（SCNP）的正交、逐步和无序展开引入作为主动控制 SCNP 折叠动力学的关键步骤。SCNP 由多个氢键和主客体相互作用压缩。通过沿侧链进行模块化连接，为具有正交识别基序的两嵌段（AB）和四嵌段（ABCD）共聚物配备了正交识别基序。最初，通过苯并-21-冠-7（B21C7，主体）和仲铵盐（AS，客体）的主客体络合诱导两嵌段共聚物的单链折叠，这代表了单链塌陷的有效途径。接下来，基于 ABCD 聚合物体系，使用正交 Hamilton 楔形（HW）和三聚氰胺（CA）以及 B21C7-AS 基序来生成 SCNP。随后，通过添加外部刺激来研究 SCNP 的逐步双重门控和无序展开。通过 1D（1）H NMR 光谱、动态光散射（DLS）和扩散有序 NMR 光谱（DOSY）来探索折叠和展开。
