biostudies-literatureYang YPNCATS NIH HHSNIAMS NIH HHSNIH HHS1458-1469https://www.ebi.ac.uk/biostudies/studies/S-EPMC8742287biostudies-literatureUnknown27(23-24)<i>In vivo</i> bioreactors are a promising approach for engineering vascularized autologous bone grafts to repair large bone defects. In this pilot parametric study, we first developed a three-dimensional (3D) printed scaffold uniquely designed to accommodate inclusion of a vascular bundle and facilitate growth factor delivery for accelerated vascular invasion and ectopic bone formation. Second, we established a new sheep deep circumflex iliac artery (DCIA) model as an <i>in vivo</i> bioreactor for engineering a vascularized bone graft and evaluated the effect of implantation duration on ectopic bone formation. Third, after 8 weeks of implantation around the DCIA, we transplanted the prevascularized bone graft to a 5 cm segmental bone defect in the sheep tibia, using the custom 3D printed Tissue engineering. Part AInvestigation of a Prevascularized Bone Graft for Large Defects in the Ovine Tibia.PMC8742287R01 AR074458K01 OD022982R01 AR057837U01 AR069395R01 AR072613L30 TR002126Lui ELabus KMLi JMcGilvray KPalmer RHGadomski BCKim SStewart HMaloney WRegan DGardner MJBruyas AYang YPMoeinzadeh SPuttlitz CMNelson BStahl AEasley JfalseInvestigation of a Prevascularized Bone Graft for Large Defects in the Ovine Tibia.<i>In vivo</i> bioreactors are a promising approach for engineering vascularized autologous bone grafts to repair large bone defects. In this pilot parametric study, we first developed a three-dimensional (3D) printed scaffold uniquely designed to accommodate inclusion of a vascular bundle and facilitate growth factor delivery for accelerated vascular invasion and ectopic bone formation. Second, we established a new sheep deep circumflex iliac artery (DCIA) model as an <i>in vivo</i> bioreactor for engineering a vascularized bone graft and evaluated the effect of implantation duration on ectopic bone formation. Third, after 8 weeks of implantation around the DCIA, we transplanted the prevascularized bone graft to a 5 cm segmental bone defect in the sheep tibia, using the custom 3D printed 2021-01-01T00:00:00Z2021 Dec2025-04-26T09:47:12.842Z2025-04-06T13:08:39.565ZS-EPMC87422873385821610.1089/ten.TEA.2020.034710.1089/ten.tea.2020.0347