Silk-Cellulose Acetate Biocomposite Materials Regenerated from Ionic Liquid

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Ionic liquids offer a promising alternative to traditional solvents for processing natural biomaterials.
• Traditional solvents often degrade protein molecular weight, limiting their use in biomedical applications.
• Polysaccharides and proteins can dissolve in ionic liquids, enabling the formation of tunable biomaterials.

Purpose of the Study:

• To investigate the structural and physical properties of blended silk fibroin protein and cellulose acetate (CA) films.
• To understand the interactions between silk fibroin and CA within an ionic liquid solvent.
• To evaluate the potential of these blended biomaterials for biomedical applications.

Main Methods:

• Regeneration of blended silk fibroin and cellulose acetate in 1-ethyl-3-methylimidazolium acetate (EMIMAc).
• Characterization using Scanning Electron Microscopy (SEM) for morphology.
• Analysis using Fourier-Transform Infrared Spectroscopy (FTIR) for secondary structure.
• Thermal analysis using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA).

Main Results:

• SEM and FTIR revealed conformational changes and strong interactions between silk fibroin and CA.
• Blended films showed altered crystalline structures, including CA crystalline and silk beta-pleated sheets.
• DSC indicated lower glass transitions in blended films due to molecular interactions.
• TGA demonstrated enhanced thermal stability in blended films compared to pure cellulose acetate.

Conclusions:

• Ionic liquid processing facilitates the creation of silk fibroin-cellulose acetate composites with significant molecular interactions.
• These composites exhibit improved thermal stability and tunable structural properties.
• The study provides foundational knowledge for developing advanced protein-polysaccharide biomaterials for diverse biomedical uses.