Development and characterization of novel bioink by using decellularized extracellular matrix for bone tissue engineering applications

Bone tissue engineering has focused on the development of functional scaffolds that can organize bone regeneration with appropriate structures and properties. Three-dimensional (3D) printing technology enables the development of personalized scaffolds. In addition, biological scaffolds obtained by decellularization have various advantages for developing natural-based scaffolds. The development of printable, patient-specific bioinks derived from decellularized extracellular matrix could provide 3D fabrication of tissues and organs with high potential to mimic native tissues. The presented thesis study demonstrates the development of various bioink compositions for bone tissue engineering applications. In this regard, bone tissues were decellularized with a novel method and then characterized in order to verify the removal of whole cellular components for eliminating immunological reactions. After the pulverization of tissues, decellularized bone (DB) particles were used as an additive within various ink combinations (alginate-, gelatin- and alginate-gelatin-based). Thus, various bioink formulations were developed containing DB particles, biopolymers and mesenchymal stem cells (MSC). All prepared bioinks were bioprinted, then the viability, proliferation and differentiation capacity of the cells inside the structures as well as the physical, rheological, and printability properties of the inks were assessed. The results revealed that all bioink combinations were suitable for bioprinting and the addition of DB particles improved cell proliferation and osteogenic differentiation in all bioink formulations. Alginate-based bioinks exhibited the greatest printability and shape fidelity, gelatin-based bioinks showed the highest cell proliferation and attachment, also, gelatin incorporation into alginate-based bioinks improved the biological activity of cells. In conclusion, cytocompatible, functional composite bioinks developed in this thesis study are of value for bone tissue engineering research in future to explore their functions in the living system and show complete bone regeneration while maintaining their stability for a long time.