Effect of pore size on in vivo osteogenesis of 3D printed scaffolds with different pore size [34]: a: 3D printed scaffolds for different tests, b: pore size 401 ± 26 μm, c: pore size 607 ± 24 μm, d: pore size 801 ± 33 μm; μ-CT analysis of inner bone formation after implantation for 4 (b1-d1) and 12 weeks (b2-d2), e1: quantitative analysis of inner new bone volume and outer bone formation after implantation for 4 (b3-d3) and 12 weeks (b4-d4), e2: Quantitative analysis of outer new bone volume; osteoblast adherence on the scaffolds on day 14 (b5-d5); Von-Gieson staining of osseointegration after implantation for 12 weeks (b6-d6), reprinted with permission.