Solid state and solution self-assembly of helical polypeptides tethered to polyhedral oligomeric silsesquioxanes

New macromolecular self-assembling building blocks, polyhedral oligo- silsesquioxane (POSS)- helical polypeptide copolymers, have been synthesized through the ring-opening polymerization (ROP) of yγ-benzyl- L-glutamate N-carboxyanhydride (yγ-Bn-Glu NCA) using aminopropyl isobutyl-POSS as a macroinitiator. The incorporation of POSS units at the chain ends of PBLG moieties has two important effects: allowing intramolecular hydrogen bonding between the POSS and PBLG units to enhance the latter's α-helical conformations in the solid state and preventing the aggregation of nanoribbons through the POSS blocks' protrusion from the ribbons to allow the formation of clear gels in solution.