Prefabrication of a Vascularized Bone Graft With Beta Tricalcium Phosphate Using an In Vivo Bioreactor

Abstract

We aimed to introduce an in vivo bioreactor-vascular pedicle threaded through the central portion of a scaffold in which a vascularized bone graft was prefabricated using adenoviral human BMP-2 gene (AdBMP2)-modified bone marrow mesenchymal stem cells (BMSCs), beta tricalcium phosphate (β-TCP), a vessel bundle, and muscularis membrane(group A). As controls, Adβgal-BMSCs/β-TCP granules, vessel bundle, and the muscularis membrane (group B); BMSCs/β-TCP granules, vessel bundle, and muscularis membrane (group C); and β-TCP granules, vessel bundle, and muscularis membrane (group D) were prepared. Formation of bone tissue and a vascular network was assessed by microangiography and histological methods 4 weeks after prefabrication. New cartilage and bone tissue in the space between β-TCP granules (mainly endochondral bone) were confirmed by histology, and a de novo vascular network circulating from the vessel bundle through newly formed bone tissue was observed in group A. Formation of bone or cartilage was not observed in the control groups. We concluded that the in vivo bioreactor is a promising method for prefabrication of vascularized functional bone.

Bone Graft Prefabrication Following the In Vivo Bioreactor Principle

“…The combined use of the AVB and tissue flap to form an IVB is advantageous due to the utilization of two well-established bone graft prefabrication strategies. We previously prefabricated vascularized bone grafts by inserting a saphenous vascular bundle into a beta tricalcium phosphate (β-TCP) scaffold wrapped within a local muscularis membrane (Han and Dai, 2013) or a periosteal flap (Han et al, 2014). The results showed a plentiful capillary network, chondrocytes, and lamella bones in the regenerated grafts.…”

Implantable electrical stimulation bioreactor with liquid crystal polymer based electrodes for enhanced bone regeneration at mandibular large defects in rabbit

“…This in vivo bioreactor system with ES benefits from one-staged direct application compared to a two-staged procedure where first the bioreactor is transplanted to the well-vascularized heterotopic sites prefabricated, and then, the regenerated tissue is transplanted to the orthotopic site [17,57].…”

Recent Advances in Scaffold Design and Material for Vascularized Tissue‐Engineered Bone Regeneration

“…In this case, β‐TCP was applied to ceramic granules with a mean pore size of 400 mm and porosity >70%, after which four different patterns were constructed. The in vivo bioreactor based on vascular pedicles at the central portion of the tissue engineering scaffold showed good vascular circulation and thus provided blood for distant organs . A honeycomb‐like PCL/TCP scaffold has also been applied with good results …”