From Macrocycles to Molecular Shuttles: Exploring the Supramolecular Assembly of Resorc[4]arenes

Self-assembly process of a well-defined structures from various chemical building blocks have found exponential growth in the development of drug delivery and bionanotechnology systems.1 In particular, these assemblies give the possibility to encapsulate a pharmaceutically active compound in their core (or at their surface) and to cargo this compound to its therapeutic target.2 Self-assembly can include different levels of complexity: it can be as simple as the dimerization of two small building blocks driven by hydrogen bonding or as complicated as a cell membrane, a remarkable supramolecular architecture created by a bilayer of phospholipids embedded with functional proteins. In addition to a vast series of natural amphiphilic structures, a number of ‘‘engineered’’ synthetic architectures have been designed, using a macrocyclic core such as cyclodextrins and crown-ethers.2 Thus, the versatility of calixarene-based macrocycles could represent promising building blocks to design amphiphiles.