Prefabrication of axially vascularized bone by combining β-tricalciumphosphate, arteriovenous loop, and cell sheet technique

The repair of bone defects poses a great challenge for reconstructive surgeons. Although the development of tisue engineering has exhibited promise in replacing damaged bone, the fabrication of large constructs with functional blood vesels remains an obstacle. From the orthopedic surgeon's point of view, the generation of axially vascularized bone, which can anastomose with the recipient vessel, might be a solution to this medical problem. In this study, we aimed to prefabricate an axially vascularized bone by combining a -TCP scaffold, arteriovenous loop (AVL), and cell sheet in a bioreactor in vivo. Twelve rabbits were randomly allocated into two groups: the experimental group (presence of AVL) and the control group (absence of AVL). The constructs were explanted at 8 weeks postoperatively. The histomorphometric results showed 42.8 +/- 5.9% of the bone area in the AVL group and 26.6 +/- 3.5% in the control group. Similarly, vessel analysis revealed the average vessel density in the AVL group (12.5 +/- 3.3) was significantly more than that in the control group (6.1 +/- 1.5, p < 0.05). Our research indicated that the combination of a -TCP scaffold, AVL and cell sheet might engineer vascularized bone. This prefabrication strategy might facilitate clinical translation of bone tissue engineering in reconstructing large bone defects.