Page 16 - Development of Functional Scaffolds for Bone Tissue Engineering Using 3D-Bioprinting of Cells and Biomaterials - Yasaman Zamani

3D-printed scaffolds (4.0 ± 0.3 MPa) was higher compared with the porous scaffolds (1.7 ± 0.2 MPa). Collagenous matrix deposition was similar on both scaffolds. Cell proliferation from day 1 to day 14 increased by 3.8-fold in the 3D-printed and by 4-fold in the porous scaffolds. ALP activity was higher by 21-fold in the 3D-printed scaffolds compared with the porous scaffolds. These results indicated that the 3D-printed PLGA/β-TCP scaffolds provide a better substrate for induction of osteogenesis by MC3T3-E1 pre-osteoblasts compared with porous scaffolds.In the last section of this thesis, bioprinting of alginate-encapsulated MC3T3-E1 pre-osteoblasts in PLGA/β-TCP scaffolds was carried out and the response of cells was evaluated by comparison with MC3T3-E1 pre-osteoblasts seeded on PLGA/β-TCP scaffolds after 3D-printing. Cell retention capacity of the bioprinted scaffolds (87 ± 3%) was higher than that of the cell-seeded scaffolds (51 ± 5%). Cells had slightly lower viability in the bioprinted scaffolds (78 ± 4%) compared with the cell-seeded scaffolds (87 ± 2%). Proliferation and ALP activity by the pre-osteoblasts was higher in the cell-seeded scaffolds compared with the bioprinted scaffolds. These results have important implications for the improvement of alginate-based bioinks with e.g. (natural) bioactive peptides for bioprinting of bone tissue engineering scaffolds.
Together, the results described in this thesis contribute to an increased understanding of the influence of properties of 3D-(bio)printed scaffolds such as surface chemistry, topography, microenvironment and biomechanics, on increasing proliferative and osteogenic differentiation potential of 3D-printed scaffolds containing osteogenic cells. These new insights can have important implications for bone tissue engineering in fields such as orthopedics and oral and maxillofacial surgery.