Bioprinting holds great promise towards engineering functional cardiac tissue constructs for regenerative medicine and as drug test models. However, it is highly limited by the choice of inks that require maintaining a balance between the structure and functional properties associated with the cardiac tissue. In this regard, we have developed a novel and mechanically robust
biomaterial-ink based on non-mulberry
silk fibroin protein. The
silk-based ink demonstrated suitable mechanical properties required in terms of elasticity and stiffness (~40 kPa) for developing clinically relevant cardiac tissue constructs. The ink allowed the fabrication of stable anisotropic scaffolds using a dual crosslinking method, which were able to support formation of aligned sarcomeres, high expression of
gap junction proteins as connexin-43, and maintain synchronously beating of cardiomyocytes. The printed constructs were found to be non-immunogenic in vitro and in vivo. Furthermore, delving into an innovative method for fabricating a vascularized myocardial tissue-on-a-chip, the
silk-based ink was used as supporting
hydrogel for encapsulating human induced pluripotent stem cell derived cardiac spheroids (hiPSC-CSs) and creating perfusable vascularized channels via an embedded bioprinting technique. We confirmed the ability of
silk-based supporting
hydrogel towards maturation and viability of hiPSC-CSs and endothelial cells, and for applications in evaluating
drug toxicity.