Synthesis of a novel bFGF/nHAP/COL bone tissue engineering scaffold for mandibular defect regeneration in a rabbit model

Abstract

In bone tissue engineering, scaffold fabrication and biocompatibility are crucial concerns. Many scaffold materials have been explored, among which nanometer hydroxyapatite (nHAP) and collagen (COL) are commonly used. Additionally, growth factors can be used to modify scaffolds. In this study, lyophilization technology was used to build a scaffold comprising basic fibroblast growth factor (bFGF), nHAP and COL for the first time. The resulting scaffold was characterized. bFGF release from the scaffold was assessed by ELISA. Bone marrow mesenchymal stem cells (BMSCs) were prepared and seeded onto the scaffold to test in vitro biological compatibility. A scanning electron microscope was used to observe the scaffold and evaluate BMSC morphology, and the cells were counted to detect early cell adhesion. Cell proliferation and activity were assessed by a cell counting kit-8 assay and measurement of alkaline phosphatase activity, respectively. Bilateral mandibular defects were prepared in 12 New Zealand rabbits and repaired using scaffolds. The rabbits were divided into four groups: a group treated with allogeneic BMSC-seeded bFGF/nHAP/COL scaffold, a group treated with allogeneic BMSC-seeded nHAP/COL scaffold, a group treated with nHAP/COL scaffold alone, and an untreated control group. After 12 weeks, three-dimensional computerized tomography examination, computerized tomography value measurement, gross observation and hematoxylin and eosin stain staining were conducted. SPSS17.0 software was used for data analysis. The gross morphology conformed to the characteristics of a tissue engineering scaffold. The bFGF/nHAP/COL scaffold promoted BMSC adhesion, proliferation and differentiation and hence promoted good bone formation, without exhibiting biological toxicity. Our findings show that the bFGF/nHAP/COL scaffold has good physical properties and biocompatibility in vitro, and can be used to promote osteogenesis after in vivo implantation.