Self-Assembly of Comb-Rod Dendritic Block Copolymers

Linear-dendritic block copolymers combine the multi-functionality of dendrimers and the phase segregated morphological behavior of block copolymers. In this work, the aqueous self-assembly of a family of comb-rod dendritic block copolymers, which consists of a monodisperse alkyl-modified hydrophobic peptide rod block, poly(n-alkyl-L-glutamate) or PALG, and a biodegradable hydrophilic polyester dendron (PED) block, was investigated using dynamic light scattering (DLS), transmission electron microscopy (TEM), and cryogenic transmission electron microscopy (Cryo-TEM). Above the critical micelle concentration (CMC), as the concentration increases, the morphology of these PALG-PED copolymers changes from micelles to vesicles. At intermediate concentrations, non-spherical nanostructures such as nanoprisms and nanotubes are observed. Reducing the length of the linear PALG block shifts the micellar phase to higher concentrations. These amphiphilic biodegradable PALG-PED copolymers offer great promise as functional tunable drug delivery carriers.