Amyloid fibril-nanocellulose interactions and self-assembly

Area of Science:

• Biomaterials Science
• Colloid and Surface Chemistry
• Polymer Science

Background:

• Amyloid fibrils from food proteins and nanocellulose are sustainable, biodegradable resources.
• These materials have potential applications in water purification, bioplastics, and biomaterials.
• Improving mechanical properties requires understanding and controlling colloidal interactions.

Purpose of the Study:

• To investigate the colloidal interactions between amyloid fibrils and nanocellulose.
• To elucidate how these interactions influence the mechanical properties of hybrid materials.
• To develop a method for creating strong, transparent biohybrid gels.

Main Methods:

• Turbidity and zeta potential measurements to assess colloidal interactions.
• Rheology to evaluate mechanical properties and elasticity.
• Atomic force microscopy to visualize material structure.
• Controlled self-assembly and dialysis for gel formation.

Main Results:

• Electrostatic interactions drive entropy-driven polyelectrolyte complexation between positively charged hen egg white lysozyme (HEWL) amyloids and negatively charged nanocellulose.
• Complexation enhances amyloid network elasticity through fibril cross-linking.
• Nanocellulose morphology influences network formation: nanocrystals induce bundling, while nanofibrils form a secondary network.
• Amyloid contribution to elasticity is independent of nanocellulose type and aligns with theoretical models.
• Strong, nearly transparent hybrid gels were successfully prepared.

Conclusions:

• Colloidal interactions, particularly electrostatic attraction, are crucial for tuning the mechanical properties of amyloid-nanocellulose hybrid materials.
• The findings provide a foundation for designing advanced functional biohybrid materials.
• Controlled self-assembly offers a pathway to creating high-performance gels from renewable biopolymers.