Preparation of orthogonally-functionalized core Click cross-linked nanoparticles

Abstract

The preparation of well-defined core cross-linked polymeric nanoparticles is reported, utilizing multi-functional dendritic cross-linkers that allow for the effective stabilization of supramolecular polymer assemblies and the simultaneous introduction of reactive groups within the core domain. Amphiphilic diblock copolymers of poly(acrylic acid)-b-poly(styrene) (PAA-b-PS) that contained alkynyl functionality, partially incorporated throughout the hydrophobic PS block segment, were utilized as Click-readied precursors for the formation of polymer micelles. Divergently-grown dendrimers of the zero, first, second and third generations, having increasing numbers of azide terminating groups ((N₃)₂-[G-0], (N₃)₄-[G-1], (N₃)₈-[G-2], and (N₃)₁₆-[G-3], respectively), were investigated as cross-linkers via Click reactions with the polymer alkynyl groups to form covalent linkages throughout the micellar core domains, thus forming core cross-linked nanoparticles. All four generations of dendrimers were found to cross-link the micelle core effectively and afford robust nanostructures, whilst simultaneously introducing Click-readied functionalities throughout the hydrophobic domain, which are proposed to be readily available for further chemical modification.