Multiblock Copolymers toward Segmentation-Driven MorphologicalTransition

Conventional\nmethods for controlling self-assembly are generally\nbased on the change in hydrophilic/hydrophobic volume fraction of\ndiblock or triblock copolymers, which suffer from low structural diversity\nand limited chemical tunability. Inspired by nature, segmented multiblock\ncopolymers (MBCs) offer unparalleled opportunities for engineering\nof biomimetic nanomaterials with tailored properties. However, the\nself-assembly of MBCs remains largely unexplored and poorly understood.\nIn this study, we report a segmentation-mediated self-assembly strategy\nto manipulate the morphology of protein-mimic responsive MBCs by facilely\naltering the block numbers while holding the amphiphilicity constant.\nIn particular, we found that an increased number of nearly alternating\nbiodegradable poly­(e-caprolactone) and hydrophilic polyethylene\nglycol segments drives micelle-to-worm-to-vesicle transition. Moreover,\nthe l-cystine residue-enriched interlayer of assemblies enables\na depolymerization-induced morphology reversion, resulting in a redox-hyper-responsive\nproperty and ultrafast intracellular drug release. Both experimental\nand computational results provide a new insight into the self-assembly\nof macromolecules and propose a convenient approach to the construction\nof smart nanoassemblies with controlled architectures.