Anisotropic, Degradable Polymer Assemblies Driven by a Rigid Hydrogen-Bonding Motif That Induce Shape-Specific Cell Responses

Poly(ethylene glycol)-conjugated amphiphilic block copolymers, which contain degradable hydrophobic blocks connected by a rigid hydrogen-bonding motif (RHM), are developed to yield anisotropic nanoassemblies in a manner independent of the crystalline nature of the hydrophobic block. The all-atom and coarse-grained molecular dynamics simulations suggest that the anisotropic alignment of the block copolymers can be attributed to the pi-pi interactions of the RHM and the crystallizable hydrophobic blocks help maintain the aligned structure. Light scattering analysis of the polymer assemblies demonstrates the formation of nonspherical assemblies by the RHM-containing block copolymers with an amorphous hydrophobic block; this indicates the strong contribution of the RHM to the directed assembly of the block copolymers, unlike crystallization-driven self-assembly. Enhanced cell proliferation is observed in cell cultures containing normal human fibroblasts in the presence of the anisotropic polymer assemblies with aspect ratios greater than 12 or lengths greater than 310 nm.

Automated summary

A novel polymer conjugate has been developed to form anisotropic nanoassemblies independent of the crystalline nature of the hydrophobic block. Molecular dynamics simulations show that rigid hydrogen-bonding motifs contribute to the anisotropic alignment of block copolymers, and amorphous hydrophobic blocks containing these motifs can form nonspherical assemblies. Enhanced cell proliferation is observed in cell cultures containing anisotropic polymer assemblies with specific aspect ratios or lengths.