Silk Fibroin Dissolution in Tetrabutylammonium Hydroxide Aqueous Solution

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Materials Science

Background:

• Bombyx mori silk fibroin (SF) is a versatile biomaterial known for its mechanical properties.
• Dissolving SF is challenging due to its insolubility in common solvents, limiting its applications.
• Developing effective dissolution methods is crucial for advanced SF-based material fabrication.

Purpose of the Study:

• To report a novel method for dissolving silk fibroin (SF).
• To investigate the conformational state and rheological properties of SF in TBAOH(aq).
• To correlate solution behavior with structural changes for advanced material development.

Main Methods:

• Dissolution of SF using 40 wt% aqueous tetrabutylammonium hydroxide (TBAOH(aq)) at mild temperatures.
• Rheological studies to analyze flow behavior and viscoelastic properties.
• Small-angle X-ray scattering (SAXS) to determine SF conformation and molecular parameters.

Main Results:

• SF was successfully dissolved in TBAOH(aq) with minimal depolymerization.
• SAXS data indicated an SF conformation close to a random coil with some compact domains.
• Rheological analysis revealed shear-thinning behavior and a transition to the semidilute regime.

Conclusions:

• A novel, mild method for dissolving silk fibroin (SF) using TBAOH(aq) was established.
• The study provides insights into SF conformation and solution behavior, crucial for material design.
• This work facilitates the creation of advanced, high-tech SF-based materials.