西北大学韩英锋团队报道了具有三角金属-金属键合单元多功能协调笼的构建与分层自组装。相关研究成果发表在2023年3月22日出版的国际知名学术期刊《美国化学会杂志》。

该文中，研究人员设计并合成了一系列用12个附加的冠醚部分官能化的带冠(Tr2M3)4L4（Tr=环庚三烯基阳离子环；M=金属；L=有机硫配体）四面体笼1-3。实现了铵阳离子与外围冠醚部分的可逆结合，以调节内部客体结合。双铵连接体和笼3的组合导致通过冠醚部分和铵盐之间的主客体相互作用形成超分子凝胶SPN1。所获得的超分子凝胶具有多刺激反应性、可注射性和优异的自愈特性，可以进一步发展为基于SPN1的药物传递系统。

此外，SPN1的储能模量比不含Pd–Pd粘结块的模型凝胶高20倍，并且SPN1与后者相比具有更好的自愈合特性，表明了此类保持架在提高机械强度而不损失材料的动态特性方面的重要性。与游离药物相比，载药（阿霉素或甲氨蝶呤）SPN1的体外细胞毒性显著提高。

附：英文原文

Title: Construction and Hierarchical Self-Assembly of Multifunctional Coordination Cages with Triangular Metal–Metal-Bonded Units

Author: Zi-En Zhang, Yi-Fan Zhang, Yan-Zhen Zhang, Hui-Ling Li, Li-Ying Sun, Li-Juan Wang, Ying-Feng Han

Issue&Volume: March 22, 2023

Abstract: Herein, a series of face-capped (Tr2M3)4L4 (Tr = cycloheptatrienyl cationic ring; M = metal; L = organosulfur ligand) tetrahedral cages 1–3 functionalized with 12 appended crown ether moieties were designed and synthesized. The reversible binding of ammonium cations with peripheral crown ether moieties to adjust internal guest-binding was realized. Combination of a bisammonium linker and cage 3 led to the formation of a supramolecular gel SPN1 via host–guest interactions between the crown ether moieties and ammonium salts. The obtained supramolecular gel exhibited multiple-stimuli responsiveness, injectability, and excellent self-healing properties and could be further developed to a SPN1-based drug delivery system. In addition, the storage modulus of SPN1 was 20 times higher than that of the model gel without Pd–Pd bonded blocks, and SPN1 had better self-healing properties compared with the latter, demonstrating the importance of such cages in improving mechanical strength without losing the dynamic properties of the material. The cytotoxicity in vitro of the drug-loaded (doxorubicin or methotrexate) SPN1 was significantly improved compared to that of free drugs.

DOI: 10.1021/jacs.3c00024

Source: https://pubs.acs.org/doi/10.1021/jacs.3c00024