Uprising Unconventional Nanobiomaterials: Peptoid Nanosheets as a Multi-Modular Platform for Advanced Biological Studies

Peptoids are bio-inspired peptidomimetic polymers that can be designed to self-assemble into a variety of nanostructures. Among these different assemblies, peptoid nanosheets are the most studied. Peptoid nanosheets are 2D highly ordered nanostructures, able to free float in aqueous solutions while featuring versatile chemical displays that can be tuned to incorporate a plethora of functional units. In this review, the synthetic approach used to prepare sequence-defined oligomers and highlight their main characteristics is introduced. The ability of peptoids to fold into nanostructures is then reviewed with an extensive emphasis on peptoid nanosheets, and their physico–chemical characteristics, assembly mechanism, and stability. A particular focus is also placed on the variety of functionalization incorporated into the peptoid nanosheets to tune their properties toward specific applications, especially within the fields of biology and medicine. Finally, the comparison between peptoid nanosheets and other 2D nanomaterials is discussed to address the challenges in the current nanomaterials and underline the future development of peptoid nanosheets in the field of biology.