Reconstruction of radial bone defects using the reinforced tissue-engineered periosteum: an experimental study on rabbit weightbearing segment.

Background: The objective of this study was to compare the osteogenic potential of reinforced and conventional tissue-engineered periosteum.

Methods: Adipose-derived stromal cells of rabbits were induced into osteoblasts. Osteoinduced cells were seeded onto chitosan-tricalcium-phosphate-gelatin (Cs-TCP-Gel) and chitosan (Cs) scaffold, thus constructing the reinforced and conventional tissue-engineered periostea, respectively. Alkaline phosphatase (ALP) and von Kossa staining protocols were used to assess osteoblast phenotype.We surgically created a 15-mm-long bone defect in the right radii of New Zealand rabbits. The defects were treated with reinforced biomimetic periosteum in group A (n = 30) and treated with conventional tissue-engineered periosteum in group B (n = 30).Group C (n = 30) received CS-TCP-Gel scaffold alone, and group D (n = 30) served as untreated side (sham group). Radiologic,histologic, immunohistochemical, and histomorphometric studies were used to analyze healing pattern.

Results: ALP was remarkably expressed in the osteoinduced cells, indicating that osteoblastic differentiation was stable. Extracellular matrix calcification with dark nodule was detected by von Kossa staining. Compared with groups B and C, histologic results demonstrated that de novo osteogenesis proliferated in group A at 4 weeks. This was further confirmed by radiographic findings, which displayed the segmental gap completely healed by mature bone at 12 weeks. Robust expression of bone morphogenetic protein-2 in group A was also evident, whereas group D displayed poor osteogenic performance. Furthermore, histomorphometric and biomechanical results in group A demonstrated statistical significance over those in other groups (p 0.05).

Conclusions: Our findings show that the reinforced tissue-engineered periosteum is superior to conventional one as a better biomimetic tissue,further indicating that it can repair the weight-bearing defects.