Silk fibroin knit scaffold for increased infiltration depth and improved elsticity in tissue engineering applications

3D scaffolds are in the center of attention for tissue engineering applications. So far, there has been continuous progress and competition in design and engineering of biomaterials as scaffold candidates for regenerative medicine[1]. Whilst biomaterials‐engineering approaches have mostly focused on a few mechanisms (mostly chemical), achieving suitable tissue biomechanical function remains an important challenge[2]. Besides, there are concerns that sustainable tissue engineering may not be achievable with current approaches[3]. This calls for further profound studies, emphasizing the need to imitate the structural and mechanical properties of the target tissue. Conventional 3D scaffolds suffer from limited depth of infiltration for cells due to their low porosity and/or not meeting the biomechanics of the target tissue, especially for regeneration of load‐bearing tissues. In this study, we have designed and fabricated a model of silk fibroin knit scaffold, which along with post‐fabrication degumming, results in a more bulky and less open structure compared with conventional knit fabrics. Our scaffold shows outstanding cell‐scaffold interaction including full 3D cell attachment, 360‐degree cell coverage around individual filaments, and full‐thickness cell infiltration depth. The optimized structure alleviates the need for the in‐advance filling of the pores and provides users with full depth access to the knit structure for increased cell adhesion and infiltration. From a mechanical viewpoint, the scaffold shows high elasticity and recovery upon unloading (up to around 90% strain), thanks to its intermeshed loops. Overall, our SF weft‐knitted construct represents appropriate characteristics for the regeneration of load bearing tissues.