Porous, Aligned, and Biomimetic Fibers of Regenerated Silk Fibroin Produced by Solution Blow Spinning

Solution blow spinning (SBS) has emerged as a rapid and scalable technique for the production of polymeric and ceramic materials into micro-/nanofibers. Here, SBS was employed to produce submicrometer fibers of regenerated silk fibroin (RSF) from Bombyx mori (silkworm) cocoons based on formic acid or aqueous systems. Spinning in the presence of vapor permitted the production of fibers from aqueous solutions, and high alignment could be obtained by modifying the SBS setup to give a concentrated channeled airflow. The combination of SBS and a thermally induced phase separation technique (TIPS) resulted in the production of macro-/microporous fibers with 3D interconnected pores. Furthermore, a coaxial SBS system enabled a pH gradient and kosmotropic salts to be applied at the point of fiber formation, mimicking some of the aspects of the natural spinning process, fostering fiber formation by self-assembly of the spinning dope. This scalable and fast production of various types of silk-based fibrous scaffolds could be suitable for a myriad of biomedical applications.