Orbital wall repair in canines with beta-tricalcium phosphate and induced bone marrow stromal cells

Bone tissue engineering is a new approach for the repair of orbital defects. The aim of the present study was to evaluate prefabricated beta-tricalcium phosphate (β-TCP) combined with autologous bone marrow stromal cells (BMSCs) to repair orbital wall defect in canine models. Defects measuring 10 mm in diameter were created in the orbital medial walls of 12 dogs. The orbits were randomly divided into five groups: group 1, repaired with osteogenesis-induced BMSCs/TCP constructs; group 2, repaired with noninduced BMSCs/TCP constructs; group 3, repaired with β-TCP scaffolds only; group 4, normal group; group 5, negative control (bone defect without treatment). Computed tomography (CT) scanning, gross observation, bone density measurements, micro-CT, and histological observations were performed. In group 1, new bone was observed with only a small amount of residual material, and bony union was achieved 3 months after surgery. In contrast, the constructs showed slow degradation with minimal bone formation in groups 2 and 3. Furthermore, the appearance and bone density of the constructs in group 1 were similar to that of normal bone: the constructs were covered with complete mucosa, and new alveolate plate grew into the ethmoidal sinuses. A large bone defect remained in group 5. This study demonstrated that biologic scaffolds composed of β-TCP and osteogenesis-induced BMSCs have been successfully used to restore bone functionality in animal models, which may provide a potential clinical approach for orbital wall repair and bone regeneration in humans.