Page 86 - Development of Functional Scaffolds for Bone Tissue Engineering Using 3D-Bioprinting of Cells and Biomaterials - Yasaman Zamani

ABSTRACT
The inability to control scaffold architecture using traditional fabrication techniques is a problem when constructing engineered tissues. Recently, 3D-printing has been used for fabrication of scaffolds with controlled shape and architecture. Here, we aimed to determine whether the much tighter control of microstructure of 3D-printed poly(lactic-co-glycolic) acid/β-tricalcium phosphate (PLGA/β-TCP) scaffolds is more effective in promoting osteogenesis than porous scaffolds produced by solvent casting-porogen leaching. Physical and mechanical properties of 3D-printed and porous scaffolds were investigated. Responses of MC3T3-E1 pre-osteoblasts to the scaffolds were analyzed after 14 days of culture. The surface of 3D-printed scaffolds was smoother (Ra: 22 ± 3 μm) compared with the highly rough surfaces of porous scaffolds (Ra: 110 ± 15 μm). Water contact angle was 76 ± 6° on 3D-printed and 112 ± 4° on porous scaffolds. 3D-printed and porous scaffolds had pore sizes of 315 ± 17 and 408 ± 90 μm, and porosities of 39 ± 7% and 85 ± 5%, respectively. Compressive strength of 3D-printed scaffolds (4.0 ± 0.3 MPa) was higher compared with 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 3D-printed and by 4-fold in porous scaffolds. Alkaline phosphatase activity was higher by 21-fold in 3D-printed scaffolds compared with porous scaffolds. In conclusion, 3D-printed scaffolds showed enhanced mechanical properties and osteogenic differentiation potential compared to porous scaffolds in vitro, suggesting that 3D-printed PLGA/β-TCP scaffolds might be more promising for in vivo bone formation.
Keywords
3D-printed scaffold, osteogenic differentiation, PLGA/β-TCP, porous scaffold, pre-osteoblasts
84