Silk fibroin electrogelation mechanisms.

Area of Science:

• Biomaterials Science
• Protein Engineering
• Nanotechnology

Background:

• Silk fibroin exhibits potential for medical materials and devices.
• Understanding the mechanism of electric field-induced gelation (e-gel) is crucial for material property control.

Purpose of the Study:

• To elucidate the mechanism of silk fibroin gel (e-gel) formation under weak electric fields.
• To investigate the role of silk fibroin nanoparticles in e-gel formation and control material properties.

Main Methods:

• Investigated silk fibroin nanoparticle formation and assembly under electric fields.
• Analyzed the influence of local pH changes near electrodes on nanoparticle interactions.
• Controlled nanoparticle content and formation for e-gel synthesis from low-concentration solutions.

Main Results:

• Silk fibroin nanoparticles (tens of nanometers) with metastable conformations are key to e-gel formation.
• Electric fields induce rapid assembly of nanoparticles into larger nano- or microspheres (tens of nanometers to several microns).
• Local pH decrease near the positive electrode screens repulsive forces, facilitating assembly.
• E-gels can be formed from 1% silk fibroin solutions by controlling nanoparticle formation.
• Reversing the process disperses assembled spheres back into solution.

Conclusions:

• Silk fibroin e-gel formation is driven by electric field-induced nanoparticle assembly.
• Precise control over nanoparticle characteristics enables tunable e-gel formation, even from dilute solutions.
• The reversible nature of e-gel formation suggests potential applications in areas like drug delivery.