Stoffelen Carmen, Huskens Jurriaan
Molecular Nanofabrication Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, Netherlands.
Nanoscale. 2015 May 7;7(17):7915-9. doi: 10.1039/c5nr01526j.
Supramolecular nanoparticles (SNPs) are of high interest in both nanoscience and molecular diagnostics and therapeutics, because of their reversible and designable properties. To ensure colloidal stabilization and biocompatibility, most reported strategies require the use of hydrophilic long-chain polymers such as poly(ethylene glycol). Here, we show the formation of zwitterionic supramolecular nanoparticles (ZSNPs) from appropriately functionalized mono- and multivalent components, based on the hetero-ternary host-guest complexation between cucurbit[8]uril (CB[8]), methyl viologen (MV), and azobenzene (Azo), while using the monovalent, small-molecule, non-fouling Azo-carboxybetaine analog (Azo-Zwit) as the shell-forming component. Even though steric shell stabilization is absent, the zwitterionic Azo-Zwit ensures stability of the ZSNPs in water, in PBS (pH 7.4) at ionic strengths ranging from 0-700 mM, and in PBS containing BSA. Size tuning by control over the stoichiometry of the components, as well as reversible assembly and disassembly by photoisomerization of the Azo moieties were observed. Surprisingly, the ZSNPs exhibited aggregation at the narrow pH range of 6.2-6.8.
超分子纳米颗粒（SNP）在纳米科学以及分子诊断与治疗领域备受关注，因其具有可逆性和可设计性。为确保胶体稳定性和生物相容性，大多数已报道的策略都需要使用亲水性长链聚合物，如聚乙二醇。在此，我们展示了基于葫芦[8]脲（CB[8]）、甲基紫精（MV）和偶氮苯（Azo）之间的异三元主客体络合作用，由适当功能化的单价和多价组分形成两性离子超分子纳米颗粒（ZSNP），同时使用单价小分子非污损性偶氮 - 羧基甜菜碱类似物（Azo - Zwit）作为壳形成组分。尽管不存在空间位阻壳层稳定作用，但两性离子Azo - Zwit确保了ZSNP在水中、离子强度范围为0 - 700 mM的PBS（pH 7.4）中以及含有牛血清白蛋白的PBS中的稳定性。观察到通过控制组分的化学计量比可调节尺寸，以及通过Azo部分的光异构化实现可逆组装和解组装。令人惊讶的是，ZSNP在6.2 - 6.8的狭窄pH范围内表现出聚集现象。
