Host-Guest Supramolecular Chemistry of Dendritic Macromolecules

Dendritic macromolecules are three-dimentional polymers with branch-on-branch topology of which dendrimers and hyperbranched polymers (HPs) are the two most researched subclasses. This paper reviews the recent progress of host-guest supramolecular chemistry in terms of various HPs and dendrimers. Because of the highly branched structure and the presence of internal space and binding sites, dendritic macromolecule can serve as host to encapsulate multiple guests, just like a highly branched "tree" accommodating multiple "bird's nests". Core-shell structure made by functionalization of dendritic polymer core with shielding shell of opposite polarity is usually needed to obtain a stable host-guest complex. Their encapsulation capacities are dependent on various factors, such as core size or molecular weight, polarity difference between core and shell, interaction strength between core and guests, shell density, and so on. Dendritic polymer-based host-guest encapsulation can be applied in many fields including phase-transfer, noncovalent functionalization, metal nanoparticle growth, and biological imaging.