Hybrid\nSilica Cage-Type Nanostructures Made from Triply\nHydrophilic Block Copolymers Single Micelles

Controlling the structure\nand functionality of porous silica nanoparticles\nhas been a continuous source of innovation with important potential\nfor advanced biomedical applications. Their synthesis, however, usually\ninvolves passive surfactants or amphiphilic copolymers that do not\nadd value to the material after synthesis. In contrast, polyion complex\n(PIC) micelles based on hydrophilic block copolymers allow for the\ndirect synthesis of intrinsically functional hybrid materials. While\nmost previous studies have focused on bulk materials made from double-hydrophilic\nblock copolymers (DHBC), in this work we have synthesized a triple-hydrophilic\nblock copolymer (THBC) and demonstrated both its PIC micellization\nand its potential for hybrid mesoporous silica nanomaterials. Introducing\nthis THBC has allowed to direct the transition from bulk three-dimensional\n(3D) materials to zero-dimensional (0D) nanomaterials with cage-type\nstructures. The stabilization and isolation of these nanostructures\nformed around discrete individual micelles has been made possible\nby the careful design of the three different blocks that each play\na key role. These nanostructures could also be synthesized from hybrid\nPIC micelles based on THBC-multivalent metal ions complexes, offering\na direct route to metal/silica composite nanoparticles. This class\nof THBC polymers therefore creates significant opportunities for the\nsynthesis of nanostructures with complex and functional architectures.