Hierarchical Helical Toroids Constructed from One-pot Controllable Self-Assembly of Polypeptides

Area of Science:

• Materials Science
• Nanotechnology
• Biomaterials

Background:

• Self-assembly is a key strategy for creating hierarchical nanostructures.
• Chiral and toroidal nanostructures are of significant interest but rarely co-exist.
• Understanding the mechanisms for complex hierarchical nanostructures is limited.

Purpose of the Study:

• To report the one-pot self-assembly of hierarchical nanostructures with both chiral and toroidal features.
• To elucidate the mechanism behind the formation of helical toroids.
• To demonstrate control over the helical sense and chirality.

Main Methods:

• One-pot self-assembly of polypeptides.
• Addition of selective solvent to polypeptide solutions.
• Dialysis to induce self-assembly and structural transformation.
• Mechanism analysis through observation of aggregate formation and transformation.

Main Results:

• Uniform toroids with controllable left-handed helical structures were successfully synthesized.
• A mechanism involving initial spherical aggregate formation followed by perforation into toroids during dialysis was identified.
• Polypeptide chain rearrangement led to ordered packing and helical structure formation within toroids.
• Chirality of the helical toroids was dependent on the polypeptide backbone chirality.

Conclusions:

• This study presents a pioneering example of one-pot self-assembly for hierarchical structures with multiple topological features.
• A straightforward and efficient strategy for constructing complex nanostructures with both chiral and toroidal characteristics has been established.
• The findings provide new insights into the self-assembly mechanisms of complex nanostructures.