Maxillary sinus floor elevation using a tissue engineered bone complex with BMP-2 gene modified bMSCs and a novel porous ceramic scaffold in rabbits

Abstract

Objectives To study the effects of maxillary sinus floor elevation by a tissue engineered bone complex with bone morphogenetic protein-2 (BMP-2) gene modified bone marrow stromal cells (bMSCs) and a novel porous ceramic scaffold (OsteoBone™) in rabbits. Materials and methods bMSCs derived from New Zealand rabbit bone marrow were cultured and transduced with adenovirus AdBMP-2 and with AdEGFP gene (without BMP-2 gene sequence) as a control, respectively, in vitro. These bMSCs were then combined with OsteoBone™ scaffold at a concentration of 2 × 10 7 cells/ml and used to elevate the maxillary sinus floor in rabbits. Eight rabbits were randomly allocated into groups and sacrificed at weeks 2 and 4. For each time point, 8 maxillary sinus floor elevation surgeries were made bilaterally in 4 rabbits for the two groups ( n = 4 per group): group A (AdBMP-2-bMSCs/material) and group B (AdEGFP-bMSCs/material). All samples were evaluated by histologic and histomorphometric analysis. Results The augmented maxillary sinus height was maintained for both groups over the entire experimental period, while new bone area increased over time for group A. At week 4 after operation, bone area in group A was significantly more than that in group B ( P < 0.05), and was more obviously detected in the center of the elevated space. Under a confocal microscope, green fluorescence in newly formed bone was observed in the EGFP group, which suggests that those implanted bMSCs had contributed to the new bone formation. Conclusion bMSCs modified with AdBMP-2 gene can promote new bone formation in elevating the rabbit maxillary sinus. OsteoBone™ scaffold could be an ideal carrier for gene enhanced bone tissue engineering.