A bio-inspired multifunctionalized silk fibroin (BMS) was synthesized in order to mimic the interaction of nidogen with the type IV collagen and laminin of basement membranes. The designed BMS consists of a motif of laminin αchain-derived, called IK peptide, and type IV collagen covalently bound to the silk fibroin (SF) by using EDC/NHS coupling and a Cu-free click chemistry reaction, respectively. Silk fibroin was chosen as the main component of the BMS because it is versatile and biocompatible, induces an in vivo favorable bioresponse, and moreover can be functionalized with different methods. The chemical structure of BMS was analyzed by using X-ray photoelectron spectroscopy, attenuated total reflection−Fourier transform infrared, cross-polarization magic angle spinning nuclear magnetic resonance techniques, and colorimetric assay. The SF and BMS solutions were cross-linked by sonication to form hydrogels or casted to make films in order to evaluate and compare the early adhesion and viability of MRC5 cells. BMS hydrogels were also characterized by rheological and thermal analyses.

Nowadays, whenever is possible and as alternative to open spine surgery, minimally invasive procedures are preferred to treat spinal cord injuries (SCI), with percutaneous injections or small incisions, that are faster, less traumatic and require less recovery time. Injectable repair systems are based on materials that can be injected in the lesion site, can eventually be loaded with drugs or even cells, and act as scaffolds for the lesion repair. The review analyzed papers written from 2010 onwards on injectable materials/systems used/proposed for the regenerative and combinatorial therapies of SCI, and discusses the in vivo models that have been used to validate them.

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