3D bioprinting of osteochondrial interface tissue

Official URL: https://risc01.sabanciuniv.edu/record=b2766964_(Table of contents)

Recent advancements in tissue engineering have demonstrated the great potential for fabrication of three-dimensional synthetic tissue structures such as cartilage and bone. However, the achievement of structural integrity between different tissues and fabrication of tissue interfaces are still great challenges. In this thesis, in situ crosslinked hybrid multi-material 3D bioprinting approach was used for the fabrication of hydrogel structures based on an aspiration-on-demand capillary method. Different cell-laden hydrogels were extruded in the same microcapillary glass and deposited in the desired geometrical arrangement. Alginate and carboxymethyl cellulose were modified with tyramine to enhance cell bioactivity and mechanical properties of Mesenchymal Stem Cells (MSC)-laden bioinks. Hydrogels were prepared for extrusion by gelling in microcapillary glass utilizing an in-situ crosslink approach using ruthenium (Ru) and sodium persulfate (SPS) photo-initiating mechanisms under visible light. The developed bioinks are then bioprinted in precise gradient composition for cartilage-bone tissue interface using aspiration-extrusion microcapillary bioprinting technique. The biofabricated constructs were co-cultured in chondrogenic/osteogenic culture media for 8 three weeks. After differentiation of MSC cells in 21-day incubation, histology, immunohistochemistry, and a live/dead test for the bioprinted structure were carried out. The results of cartilage and bone formation analysis based on cell alignment and histological evaluation successfully revealed that mechanical cues, in conjunction with chemical cues, showed MSC to differentiate into chondrogenic and osteogenic tissues.