Abstract text (incl. figure legends and references)
Introduction
Silk fibroin combines properties such as high mechanical strength, biocompatibility, and biodegradability in vivo. The possibility of using fibroin in a wide variety of formats (films, scaffolds, hydrogels, and micro- or nanoparticles for drug delivery), has led to many interesting applications in medical research. In addition, extensive effort has been focused on producing man-made silk fibers by wet spinning. However, due to degradation of fibroin molecules during isolation from cocoons only high percentage solutions of regenerated silk (13-32 % w/v) show sufficient viscosity needed for fiber spinning.
Objectives
The main objective was to develop a novel wet spinning process to generate silk fibers and to process those fibers into 3D open porous scaffolds applying textile fiber-based additive manufacturing.
Materials & methods
Regenerated silk solution was isolated from Bombyx mori cocoons applying mild degumming and dissolution in ZnCl2. The resulting solution was freeze-dried and re-dissolved for wet spinning. Wet spun silk fibers were processed into staple fibers and then assembled into open porous 3D scaffolds applying fiber-based additive manufacturing.
Results
In contrast to all previously published spinning processes, a solvent/coagulation bath combination was developed, which enables continuously spinning of endless fibers from only 4 % (w/v) silk solution. Compared to other approaches the solid content to tensile strength ratio achieved was twice that of the highest process to date. Applying fiber-based additive manufacturing, those wet spun silk fibroin fibers were processed into 3D open porous scaffolds.
Conclusion
A novel process was developed enabling wet spinning of fibers from only 4 % (w/v) fibroin solution, which could be processed into 3D scaffolds with a fiber-based additive manufacturing technology.
Acknowledgements
This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)-437213841.