Tubular mPCL scaffolds with an internal diameter of 5 mm were fabricated via melt electrowriting and CaP-coated as described above5 (link),7 ,25 (link). The mPCL-CaP tubular scaffolds were seeded with 100,000 hOB/scaffold in 30 µl serum-free MEMα and cultured in well-plates for 2 weeks in expansion media followed by 7 weeks in osteogenic media. Throughout the course of the scaffold culture, hOBs migrated from the scaffold onto the tissue-culture plastic of the well plates and formed a hOB monolayer. The hOB monolayers were cultured together with the scaffold and were allowed to form a hOB cell sheet.
A prevascularized niche was generated using 4% GelMA-based hydrogels containing HUVECs and MSCs (10:1 ratio; 5.5 × 106 cells/ml total) 7 days before implantation and pre-cultured in EGM2 (PromoCell, Heidelberg, Germany) supplemented with 125 ng/ml SDF-1α, VEGF and FGF2 (Miltenyi Biotec, NSW, Australia). At the time of implantation, the vascular gel was placed inside the tubular hOB scaffold. The hOB cell sheet was mixed with 30 µl fibrin glue (TISSEEL™ kit, Baxter Healthcare, Australia) and 20 µl of rhBMP-2 (1.5 µg/µl; INFUSE®, Medtronic25 (link). Two tubular hTEBC were implanted into left and right subcutaneous pockets on the back of male NSG mice as described above.
A prevascularized niche was generated using 4% GelMA-based hydrogels containing HUVECs and MSCs (10:1 ratio; 5.5 × 106 cells/ml total) 7 days before implantation and pre-cultured in EGM2 (PromoCell, Heidelberg, Germany) supplemented with 125 ng/ml SDF-1α, VEGF and FGF2 (Miltenyi Biotec, NSW, Australia). At the time of implantation, the vascular gel was placed inside the tubular hOB scaffold. The hOB cell sheet was mixed with 30 µl fibrin glue (TISSEEL™ kit, Baxter Healthcare, Australia) and 20 µl of rhBMP-2 (1.5 µg/µl; INFUSE®, Medtronic25 (link). Two tubular hTEBC were implanted into left and right subcutaneous pockets on the back of male NSG mice as described above.