Enhancement of bone formation by BMP‐7 transduced MSCs on biomimetic nano‐hydroxyapatite/polyamide composite scaffolds in repair of mandibular defects

Abstract

AbstractThis study was to evaluate enhanced bone formation by bone morphogenetic protein‐7 (BMP‐7) transduced MSCs on nano‐hydroxyapatite/polyamide (n‐HA/PA) composite scaffolds for bone tissue engineering in repair of mandibular defect. n‐HA/PA scaffolds were prepared and rabbit MSCs were separated and expanded; and then infected with adenoviral‐mediated BMP‐7 in vitro. The MSCs‐BMP‐7 and MSCs were seeded on the porous scaffolds. Scaffold/MSCs‐BMP‐7 constructs and scaffold/MSCs constructs were implanted in the defects of rabbits' mandible as the experimental groups A (n = 18) and groups B (n = 18), respectively, the pure scaffolds were implanted as controls (group C, n = 18). Six animals were sacrificed at 4‐, 8‐, and 16‐week postimplantation, respectively. Their mandibles were removed and processed for radiographic, biomechanical tests, histological, and histomorphometric analysis. Group A animals showed greater bone formation and earlier mineralization than group B at 4‐ and 8‐week postimplantation and similarly group B more than group C. However, no difference was found among three groups at 16‐week postimplantation. The results of this study suggest that BMP‐7 transduced MSCs‐n‐HA/PA composite could significantly accelerate bone formation in the implant at early stage. BMP‐7 mediated ex vivo gene transfer based on MSCs as seed cells, combined with porous n‐HA/PA as scaffolds for bone tissue engineering might be an alternative or supplemental approach to repair the mandibular defects. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.