Therapeutic viruses: A filament‐shaped artificial virus is formed by using a preorganized supramolecular nanoribbon as a template. The artificial virus (see picture), which is composed of the nanoribbon, small interfering RNAs (blue, double‐helix shape), and hydrophobic guests (red), is highly efficient in delivering genes and drugs to the inside of cells.

Peptide rod-coil molecules, composed of a stiff polyproline rod and a hydrophilic cell-penetrating peptide Tat coil, self-assemble into nanocapsules and mediate efficient intracellular delivery of entrapped hydrophilic molecules.

We explored a method of controlling bacterial motility and agglutination by using self-assembled carbohydrate-coated beta-sheet nanoribbons. To this aim, we synthesized triblock peptides that consist of a carbohydrate, a polyethylene glycol (PEG) spacer, and a beta-sheet-forming peptide. An investigation into the effect of PEG-spacer length on the self-assembly of the triblock peptides showed that the PEG should be of sufficiently length to stabilize the beta-sheet nanoribbon structure. It was found that the stabilization of the nanoribbon led to stronger activity in bacterial motility inhibition and agglutination, thus suggesting that antibacterial activity can be controlled by the stabilization strategy. Furthermore, another level of control over bacterial motility and agglutination was attained by co-assembly of bacteria-specific and -nonspecific supramolecular building blocks. The nanoribbon specifically detected bacteria after the encapsulation of a fluorescent probe. Moreover, the detection sensitivity was enhanced by the formation of bacterial clusters. All these results suggest that the carbohydrate-coated beta-sheet nanoribbons can be developed as promising agents for pathogen capture, inactivation, and detection, and that the activity can be controlled at will.

β-Barrel proteins that take the shape of a ring are common in many types of water-soluble enzymes and water-insoluble transmembrane pore-forming proteins. Since β-barrel proteins perform diverse functions in the cell, it would be a great step towards developing artificial proteins if we can control the polarity of artificial β-barrel proteins at will. Here, we describe a rational approach to construct β-barrel protein mimics from the self-assembly of peptide-based building blocks. With this approach, the direction of the self-assembly process toward the formation of water-soluble β-barrel nanorings or water-insoluble transmembrane β-barrel pores could be controlled by the simple but versatile molecular manipulation of supramolecular building blocks. This study not only delineates the basic driving force that underlies the folding of β-barrel proteins, but also lays the foundation for the facile fabrication of β-barrel protein mimics, which can be developed as nanoreactors, ion- and small-molecule-selective pores, and novel antibiotics.