Upcycling bovine bone waste into hybrid collagen scaffolds for 3D bioprinting application and bone regeneration

Nowadays, with the increasing population, bovine bone waste obtained from the growing food industry has been evaluated and an environmentally sustainable hybrid bone graft material has been developed. Bioinks for 3D bioprinting applications were prepared by combining native collagen extracted from demineralized bovine bones with inorganic components such as hydroxyapatite, beta-tricalcium phosphate and bioactive glass. Rheological tests as a result of the characterization of bioinks revealed that printability and thermal stability increased in mineral-added groups. In vitro bio-compatibility analyses of grid-structured scaffolds produced with extrusion-based 3D printing were performed with human bone marrow-derived mesenchymal stem cells; cell viability was evaluated with MTT and the cell counting kit-8 tests performed on days 1, 4 and 7. In addition, cell morphology was examined with phalloidin/4 ',6-Diamidine-2 '-phenylindole dihydrochloride staining. All mineral-added collagen scaffolds supported cell adhesion and proliferation, and cell viability and cytoskeletal organization were determined to be higher in groups containing hydroxyapatite and beta-tricalcium phosphate. Transforming animal-derived waste into high value-added biomaterials is an innovative approach that can be applied in tissue engineering and supports environmental sustainability. The developed bioinks are promising candidates in 3D bioprinting technology to produce personalized bone grafts.