Background and aimsTissue-engineering approachcan result insignificant bone regeneration. We aims to reconstruct the segmental orbital rim defects with antigen-free bovine cancellous bone (BCB) scaffolds combined with bone marrow mesenchymal stem cells (BMSCs) in rats.
Methods BCB was prepared by degreasing, deproteinization and partly decalcification. BMSCs isolated from green fluorescent protein (GFP) transgenic Sprague-Dawley (SD) rats were osteogenically induced and seeded onto BCB scaffolds to construct induced BMSCs/BCB composites. A 5mm full-thickness defect on the rat inferior-orbit rim was established. Induced BMSCs/BCB composites cultured for 10 days were implanted into the orbital defects as experimental group. Noninduced BMSCs/BCB group, BCB group and exclusive group were set. General condition, spiral CT, 3D orbital reconstruction, histological and histomorphometric analysis were performed after implantation.
Results BCB presented reticular porous structure. GFP-BMSCs adhering to BCBappearedbright green fluorescence and grew vigorously. Infection and graft dislocation weren’t observed. In induced BMSCs/BCB group, spiral CT and 3D reconstruction showed perfect orbital repair situation. Histological analysis indicated BCB was biodegraded mostly; newly-formed bone and complete synostosis were observed. The percentage of newly-formed bone was (57.12±6.28)%. In contrast, more residual BCB, less newly-formed bone and nonunion were observed in noninduced BMSCs/BCB group. Slowly-absorbed BCB enwrapped by fibrous connective tissue and a small amount of new bone occurred in BCB group. Fibrous connective tissue appeared in exclusive group.
Conclusion BCB combined with BMSCs is a promising composite for tissue engineering and can effectively reconstruct the orbit rim defects.