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Updated: Dec 2, 2025

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Solvent-Controlled Topological Evolution from Nanospheres to Superhelices.

Minggao Qin1, Yongfang Li2, Yaqian Zhang1

  • 1State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.

Small (Weinheim an Der Bergstrasse, Germany)
|November 2, 2020
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Summary

This study reveals the dynamic self-assembly of l-tryptophan derivatives from nanospheres to superhelical nanofibers. These distinct structures influence neural stem cell differentiation, offering insights into protein fibrillation.

Keywords:
cell differentiationl-tryptophanself-assemblysupramolecular chiralitytopological evolution

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Area of Science:

  • Supramolecular chemistry
  • Materials science
  • Biomaterials engineering

Background:

  • Supramolecular assemblies' diverse morphologies are critical for their properties.
  • The mechanisms, intermediates, and topological evolution of self-assembly remain poorly understood.

Purpose of the Study:

  • To elucidate the dynamic morphological evolution of a minimal l-tryptophan-based derivative (LPWM) during self-assembly.
  • To investigate the driving forces behind topological transformations.
  • To evaluate the impact of different morphologies on neural stem cell (NSC) differentiation.

Main Methods:

  • Self-assembly of LPWM in various mixed solvent systems.
  • Morphological characterization through observation of nanosphere formation, fusion, disintegration, distortion, and entanglement.
  • Analysis of driving forces including hydrogen bonding and hydrophobic effects.
  • Assessment of NSC differentiation on nanosphere and nanofiber scaffolds.

Main Results:

  • A dynamic morphological evolution from solid nanospheres to superhelical nanofibers was observed.
  • Key transformations included nanosphere fusion into necklaces, disintegration into nanofibers, distortion into nanotwists, and entanglement into superhelices.
  • Breakage of intramolecular H-bonds and reconstruction of intermolecular H-bonds, alongside altered aromatic and hydrophobic interactions, drove topological changes.
  • Nanofibers promoted NSC differentiation into neurons, while nanospheres had a negligible effect.

Conclusions:

  • The study demonstrates a tunable self-assembly process yielding diverse supramolecular morphologies.
  • The findings highlight the critical role of molecular interactions in controlling topological evolution.
  • The developed system serves as a model for understanding protein fibrillation and structure-function relationships in biomaterials.