Bacterial cellulose nanocrystals-embedded silk nanofibers

Area of Science:

• Biomaterials Science
• Materials Engineering
• Nanotechnology

Background:

• Silk fibroin is a natural polymer with potential in biomedical applications.
• Bacterial cellulose nanocrystals (BCNs) are known for their unique mechanical and structural properties.
• Combining these materials could lead to novel nanofibrous composites with improved performance.

Purpose of the Study:

• To fabricate and characterize bacterial cellulose nanocrystals (BCNs)-embedded silk fibroin nanofibers.
• To investigate the effect of varying BCNs concentrations on the morphology, structure, and mechanical properties of silk fibroin nanofibers.
• To explore the potential for enhanced mechanical properties through BCNs incorporation.

Main Methods:

• Electrospinning was used to fabricate silk fibroin/BCNs nanofibers with BCNs concentrations ranging from 0 to 7 wt%.
• Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and X-ray Diffraction (XRD) were employed for structural analysis.
• Fourier Transform Infrared Spectroscopy (FT-IR) was used to analyze conformational changes in silk fibroin.
• Mechanical properties, specifically Young's modulus, were measured.

Main Results:

• The average diameter of silk fibroin/BCNs nanofibers increased from 230 to 430 nm with increasing BCNs content.
• FT-IR analysis confirmed a conformational transition of silk fibroin from random coil to beta-sheet structure.
• Young's modulus significantly increased, particularly between 3 and 5 wt% BCNs, due to the formation of a BCN percolation structure.

Conclusions:

• Electrospun silk fibroin nanofibers successfully incorporated bacterial cellulose nanocrystals (BCNs).
• The addition of BCNs induced a beneficial structural transition in silk fibroin, enhancing mechanical properties.
• A percolation structure of BCNs between 3-5 wt% significantly boosted the Young's modulus of the composite nanofibers.