[BMP-2 gene modified tissue-engineered bone repairing segmental tibial bone defects in goats]

Abstract

Objective: To evaluate the effectiveness of the tissue-engineered bone substitute loaded with adenovirus mediated human bone morphogenetic protein-2 gene (Adv-hBMP-2) transfected bone marrow derived mesenchymal stem cells (BMSC) in the repair of diaphyseal segmental bone defect of large animal.

Methods: The right tibial bone defects (2.6 cm) model of 26 goats were established and divided into 5 groups: I. Adv-hBMP-2 transfected BMSC/calcined bone (CB) group (n = 9); II. adenovirus-beta-galactosidase (Adv-betagal) gene transfected BMSC/CB group (n = 6); III. untransfected BMSC/CB group (n = 6); IV. single CB group (n = 3); VI. untreated group (n = 2). The above tissue-engineered bone substitutes were implanted in the bone defects respectively except group VI. Roentgenography, histomorphometrical analysis and biomechanical measurement were studied at various times.

Results: X-ray: at 4 - 8th weeks after implantation, more bony callus was found in the bone defects of group I. The complete healing rates of group I, II, III, IV, and V were 5/8, 1/5, 0/5, 0/2, 0/1 respectively at 26th week after implantation. Histomorphometrical analysis showed much more new bony callus including cortical bone formed in group I than those of other groups. The compression strength of the implanted bone substitute of group I is significantly higher than those of group II and III.

Conclusion: The tissue-engineered bone substitute loaded with human BMP-2 gene transfected BMSC can repair diaphyseal segmental bone defect of large animal (goat).