PNNL

Abstract

Due to the various applications enabled by the diverse morphologies of self-assembled sequence-defined polymers, controlling the self-assembly of synthetic peptidomimetics into designed morphologies has emerged as a promising route for the development of bioinspired functional materials. Herein, we report the morphological control over the assembly of a series of short peptoids, or poly-N-substituted glycines, that contain anisotropic hydrophobic domains. We demonstrate the flexibility of amphiphilic peptoid bilayers leads to the assembly polymorphism: the co-existence of nanosheets, twisted ribbons, and nanofibers, three different morphologies. By tuning peptoid molecular interactions through the variation of sequence design, solution pH, and temperature, we further demonstrate the control over twisting and folding of peptoid bilayers that lead to the formation of specific nanosheets and nanohelices. Molecular dynamics simulations further unravel how the introduction of anisotropic hydrophobic domains enables the flexibility of peptoid bilayers and results in the peptoid assembly polymorphism. By tuning peptoid molecular interactions through heating, we further demonstrate the transformation of nanosheets into nanohelices. We envision that our mechanistic investigation of peptoid assembly polymorphism serves a powerful foundation for translating peptoid sequences and chemistries into controlled molecular interactions, driving the creation of biomimetic materials with precise morphologies and functionalities.