An ability to develop sequence-defined synthetic polymers that both mimic lipid amphiphilicity for self-assembly of highly stable membrane-mimetic 2D nanomaterials and exhibit protein-like functionality would revolutionize the development of biomimetic membranes. Here we report the assembly of lipid-like peptoids into highly stable, crystalline, free-standing and self-repairing membrane-mimetic 2D nanomaterials through a facile crystallization process. Both experimental and molecular dynamics simulation results show that peptoids assemble into membranes through an anisotropic formation process. We further demonstrated the use of peptoid membranes as a robust platform to incorporate and pattern functional objects through large side-chain diversity and/or co-crystallization approaches. Similar to lipid membranes, peptoid membranes exhibit changes in thickness upon exposure to external stimuli; they can coat surfaces in single layers and self-repair. We anticipate that this new class of membrane-mimetic 2D nanomaterials will provide a robust matrix for development of biomimetic membranes tailored to specific applications.

Herein, we report a novel Janus particle and supramolecular block copolymer consisting of two chemically distinct hyperbranched polymers, which is coined as Janus hyperbranched polymer. It is constructed by the noncovalent coupling between a hydrophobic hyperbranched poly(3-ethyl-3-oxetanemethanol) with an apex of an azobenzene (AZO) group and a hydrophilic hyperbranched polyglycerol with an apex of a β-cyclodextrin (CD) group through the specific AZO/CD host-guest interactions. Such an amphiphilic supramolecular polymer resembles a tree together with its root very well in the architecture and can further self-assemble into unilamellar bilayer vesicles with narrow size distribution, which disassembles reversibly under the irradiation of UV light due to the trans-to-cis isomerization of the AZO groups. In addition, the obtained vesicles could further aggregate into colloidal crystal-like close-packed arrays under freeze-drying conditions. The dynamics and mechanism for the self-assembly of vesicles as well as the bilayer structure have been disclosed by a dissipative particle dynamics simulation.

Despite recent advances in the assembly of organic nanotubes, conferral of sequence-defined engineering and dynamic response characteristics to the tubules remains a challenge. Here we report a new family of highly designable and dynamic nanotubes assembled from sequence-defined peptoids through a unique “rolling-up and closure of nanosheet” mechanism. During the assembly process, amorphous spherical particles of amphiphilic peptoid oligomers crystallize to form well-defined nanosheets before folding to form single-walled nanotubes. These nanotubes undergo a pH-triggered, reversible contraction–expansion motion. By varying the number of hydrophobic residues of peptoids, we demonstrate tuning of nanotube wall thickness, diameter, and mechanical properties. Atomic force microscopy-based mechanical measurements show peptoid nanotubes are highly stiff (Young’s Modulus ~13–17 GPa). We further demonstrate the precise incorporation of functional groups within nanotubes and their applications in water decontamination and cellular adhesion and uptake. These nanotubes provide a robust platform for developing biomimetic materials tailored to specific applications.

Self-assembly of amphiphilic hyperbranched polymers (HBPs) is a newly emerging research area and has attracted increasing attention due to the great advantages in biomedical applications. This tutorial review focuses on the self-assembly of biocompatible or biodegradable amphiphilic HBPs and their cytomimetic applications, and specialities or advantages therein owing to the hyperbranched structure have also been summarized. As shown here, various supramolecular structures including micelles, vesicles, tubes, fibers and films have been prepared through the primary self-assembly processes. The primary self-assemblies can be further assembled into more complex structures through hierachical self-assembly processes. Besides, the hyperbranched polymer vesicles have demonstrated great potential to be used as model membranes to mimic cellular behaviors, such as fusion, fission and cell aggregation. Other biomedical applications of HBPs as well as their self-assemblies are also briefly summarized.

A series of secondary amine-modified cyclodextrin (CD) derivatives were synthesized with diverse exterior terminal groups (i.e., hydroxyl, methyl, methoxyl, and primary amine). Subsequent reaction with nitric oxide (NO) gas under alkaline conditions yielded N-diazeniumdiolate-modified CD derivatives. Adjustable NO payloads (0.6–2.4 µmol/mg) and release half-lives (0.7–4.2 h) were achieved by regulating both the amount of secondary amine precursors and the functional groups around the NO donor. The bactericidal action of these NO-releasing cyclodextrin derivatives was evaluated against Pseudomonas aeruginosa, a Gram-negative pathogen with antibacterial activity proving dependent on both the NO payload and exterior modification. Materials containing a high density of NO donors or primary amines exhibited the greatest ability to eradicate P. aeruginosa. Of the materials prepared, only the primary amine-terminated hepta-substituted CD derivatives exhibited toxicity against mammalian L929 mouse fibroblast cells. The NO donor-modified CD was also capable of delivering promethazine, a hydrophobic drug, thus demonstrating potential as a dual-drug releasing therapeutic.