Silk Fibroin/Elastin Bioinks for 3D Printing of Implants Respecting the Patient Intervertebral Disc Anatomy

: Lower Back Pain associated to intervertebral disc (IVD) degeneration is estimated to affect up to 80% of the population at some point in their lives (Silva-Correia et al. 2013). It is one of the most frequently reported age- and work-related disorder in actual society, leading to a huge socio-economic impact in industrialized countries. Current treatment focus on pain alleviation and do not attempt to restore patient’s disc structure and biomechanics. Therefore, there is an increasing interest in the potential use of patient-specific cell-based tissue engineering (TE) approaches aimed to regenerate the injured IVD and successfully reestablish total disc function. One potential strategy would combine imaging techniques (e.g. MRI and micro-CT) with 3D-bioprinting technology to address IVD regeneration/substitution. Our group has recently proposed for the first time the use of a fast-setting bioink based on enzymatically crosslinked silk fibroin (SF) hydrogel for 3D printing of patient-specific memory-shape implants (Costa et al. 2017). Herein, the previously developed SF bioink was blended with elastin to bioprint personalized substitutes respecting the anatomy of the outer region of the IVD (i.e. annulus fibrosus, AF). The bioprinted SF/elastin scaffolds were characterized thoroughly in vitro, in terms of physico-chemical properties and cell-materials interaction.