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After an injury, the limited regenerative capacity of the central nervous system makes the reconnection and functional recovery of the affected nervous tissue almost impossible. To address this problem, biomaterials appear as a promising option for the design of scaffolds that promote and guide this regenerative process. Based on previous seminal works on the ability of regenerated silk fibroin fibers spun through the straining flow spinning (SFS) technique, this study is intended to show that the usage of functionalized SFS fibers allows an enhancement of the guidance ability of the material when compared with the control (nonfunctionalized) fibers. It is shown that the axons of the neurons not only tend to follow the path marked by the fibers, in contrast to the isotropic growth observed on conventional culture plates, but also that this guidance can be further modulated through the biofunctionalization of the material with adhesion peptides. Establishing the guidance ability of these fibers opens the possibility of their use as implants for spinal cord injuries, so that they may represent the core of a therapy that would allow the reconnection of the injured ends of the spinal cord. [ABSTRACT FROM AUTHOR]

High-performance regenerated silkworm (Bombyx mori) silk fibers can be produced efficiently through the straining flow spinning (SFS) technique. In addition to an enhanced biocompatibility that results from the removal of contaminants during the processing of the material, regenerated silk fibers may be functionalized conveniently by using a range of different strategies. In this work, the possibility of implementing various functionalization techniques is explored, including the production of fluorescent fibers that may be tracked when implanted, the combination of the fibers with enzymes to yield fibers with catalytic properties, and the functionalization of the fibers with cell-adhesion motifs to modulate the adherence of different cell lineages to the material. When considered globally, all these techniques are a strong indication not only of the high versatility offered by the functionalization of regenerated fibers in terms of the different chemistries that can be employed, but also on the wide range of applications that can be covered with these functionalized fibers. [ABSTRACT FROM AUTHOR]

We address the production of structures intended as conduits made from natural biopolymers, capable of promoting the regeneration of axonal tracts. We combine hyaluronic acid (HA) and silk fibroin (SF) with the aim of improving mechanical and biological properties of HA. The results show that SF can be efficiently incorporated into the production process, obtaining conduits with tubular structure with a matrix of HA-SF blend. HA-SF has better mechanical properties than sole HA, which is a very soft hydrogel, facilitating manipulation. Culture of rat Schwann cells shows that cell adhesion and proliferation are higher than in pure HA, maybe due to the binding motifs contributed by the SF protein. This increased proliferation accelerates the formation of a tight cell layer, which covers the inner channel surface of the HA-SF tubes. Biocompatibility of the scaffolds was studied in immunocompetent mice. Both HA and HA-SF scaffolds were accepted by the host with no residual immune response at 8 weeks. New collagen extracellular matrix and new blood vessels were visible and they were present earlier when SF was present. The results show that incorporation of SF enhances the mechanical properties of the materials and results in promising biocompatible conduits for tubulization strategies. • Tubular scaffold intended as nerve guidance conduit made from combination of hyaluronic acid and silk fibroin • Enhanced mechanical and biological properties due to the presence of silk fibroin • Proven in vivo biocompatibility of the scaffold, that was accepted by the host after 8 weeks • Promising biocompatible scaffold for use in tissue engineering [ABSTRACT FROM AUTHOR]