Repair of rat mandibular bone defects by alveolar osteoblasts in a novel plasma-derived albumin scaffold.

Abstract

Repair of bone deficiencies in the craniofacial skeleton remains a difficult clinical problem. The aim of this study was to evaluate a novel albumin scaffold seeded with human alveolar osteoblasts and implanted into experimental mandibular defects. An experimental solid protein scaffold was prepared with human plasmatic albumin crossed with a glutaraldehyde-type agent. Microstructure of scaffold and mechanical properties were examined using scanning electron microscopy and a stress-controlled rheometer. Bilateral critical mandibular defects were created in eight immunodeficient rats. Defects of the right side of the mandibles received the cell-scaffold construct in all animals. All left mandibular defects were left untreated as blank controls. Sections of the defects were collected at 5, 8, and 11 weeks postsurgery and processed for histological and immunohistochemical observation, computed tomography examination, and computed tomography digital analysis. Histologically, bone formation was observed in both groups at 5 weeks postsurgery, and the engineered bone became more mature after 8 and 11 weeks, which was similar to normal bone. The origin of bone-forming cells within the defects and the localization of implanted human osteoblasts were confirmed by human vimentin expression. No bone formation could be observed at any control defect. Bone density after 8 weeks was significantly higher than that of the 5-week group (p = 0.02), and significant differences were also observed between 8 and 11 weeks (p < 0.01). The results indicate the clinical feasibility of albumin scaffold loaded with human alveolar cells and that it can be used as a good alternative for bone regeneration.