Diversiform and Transformable Glyco-Nanostructures Constructed from Amphiphilic Supramolecular Metallocarbohydrates through Hierarchical Self-Assembly: The Balance between Metallacycles and Saccharides

Guang Yang#, Wei Zheng#, Guoqing Tao, Libin Wu, Qi-Feng Zhou, Zdravko Kochovski, Tan Ji, Huaijun Chen, Xiaopeng Li, Yan Lu, Hong-ming Ding*, Hai-Bo Yang*,  Guosong Chen,* and Ming Jiang (#: Co-first authors)

ABSTRACT: During the past decade, self-assembly of saccharides-containing amphiphilic molecules toward bioinspired functional glyco-materials has attracted continuous attention due to their various applications in fundamental and practical areas. However, it still remains a great challenge to prepare hierarchical glyco-assemblies with controllable and diversiform structures because of the complexity of saccharide structures and carbohydrate-carbohydrate interactions. Herein, through hierarchical self-assembly of modulated amphiphilic supramolecular metallocarbohydrates, we successfully prepared various well-defined glyco-nanostructures in aqueous solution, including vesicles, solid spheres and opened vesicles depending on the molecular structures of metallocarbyhydrates. More attractively, these glyco-nanostructures can further transform into other morphological structures in aqueous solutions such as worm-like micelles, tubules and even tupanvirus-like vesicles (TVVs). It is worth to mention that distinctive anisotropic structures including the opened vesicles (OVs) and TVVs were  rarely reported in glyco-based nano-objects. This intriguing diversity was mainly controlled by the subtle structural trade-off of the two major components of the amphiphiles, i.e. the saccharides and metallacycles. To further understand this precise structural control, molecular simulations provided the deep physical insights on the morphology evolution and balancing of the contributions from saccharides and metallacycles. Moreover, the multivalency of glyco-nanostructures with different shapes and sizes was demonstrated by agglutination with a diversity of sugar-binding protein receptors such as the plant lectins concanavalin A. This modular synthesis strategy provides access to systematic tuning of molecular structure and self-assembled architecture, which undoubtedly will broaden our horizons on the controllable fabrication of biomimetic glyco-materials such as biological membranes and supramolecular lectin inhibitors.