Ultrasonic-assisted refinement of domesticated-wild silk protein composite nanofibers: enhancing miscibility,...

Silk fibroin is highly regarded for its exceptional biocompatibility, degradability, and mechanical properties, making it a valuable material in the field of tissue engineering. Ultrasound technology, recognized as a safe and efficient physical method, enables precise manipulation of material microstructures and macroscopic properties, which is essential for the development of innovative high-performance biomaterials. This study aims to enhance the solution miscibility, fiber uniformity, and properties of silk-based protein nanofiber materials by employing a silk-silk composite approach. The method involved air-spinning of Tussah silk fibroin (TSF) and Bombyx mori silk fibroin (BSF) blends through ionic liquid dissolution, combined with ultrasound-assisted processing. Comprehensive characterization, including SEM, FTIR, XRD, ¹³C NMR, DSC, TGA, AFM, WCA, revealed that the original TSF/BSF composite exhibited weak hydrogen bonding interactions, resulting in uneven protein fibers. Moderate ultrasound treatment facilitated the formation of uniform fibers and their interlacing, significantly enhancing the interactions between TSF and BSF. This process promoted the efficient miscibility of TSF with BSF, thereby mitigating the occurrence of microphase separation. It led to increased β-sheet crystalline content, improved thermal and mechanical properties, and enhanced hydrophilicity, biocompatibility, and biodegradation rates. Therefore, integrating protein composites with ultrasound processing produces uniform nanofiber biomaterials with superior structural and biological properties, opening up new perspectives for their application in biomedicine.