Withdrawal: Synthesis of a Novel bFGF/nHAP/COL Bone Tissue Engineering Scaffold for Mandibular Defect Regeneration in a Rabbit Model [Journal of Hard Tissue Biology 27(1) Vol.27, 2018, pp 85-94]

<p>We have withdrawn following article.</p><p>　</p><p>“Synthesis of a Novel bFGF/nHAP/COL Bone Tissue Engineering Scaffold for Mandibular Defect Regeneration in a Rabbit Model” by Yue Cai, Xuexin Tan, Li Zhao, Ran Zhang, Tong Zhu, Yang Du and Xukai Wang in Journal of Hard Tissue Biology 27(1): 85-94, 2018.</p><p>　</p><p>This article has been withdrawn at the request of all the authors. This article reports that a fibroblast growth factor (bFGF) releasing nanometer hydroxyapatite (nHAP)/ collagen (COL) scaffolds promoted osteo-differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro and repaired bone defects in vivo. We have recently repeated the experiments and intended to research the mechanisms deeply. Unexpectedly, the results were opposite to this published article: bFGF releasing nHAP/ COL scaffolds promoted BMSCs proliferating not osteo-differentiating, the scaffolds didn’t significantly promote bone repair in rabbit mandibular defects neither. Similarly, some researches reported that bFGF exhibited no positive even inhibitory effects on bone formation. As these literatures demonstrated, the effects of bFGF in osteo-differentiation are controversial, which were dose and time dependent, and may be related to the variable origins and commitment states of cells in applied in vitro and in vivo models. Low concentration bFGF might have osteostimulative effects, while high concentration had inhibitory effects. Furthermore, bFGF at the same dose exhibited opposite effects when combined with hydroxyapatite or demineralized bone matrix^1-7). Recent researches preferred to apply bFGF together with bone morphogenetic proteins (BMPs) or transforming growth factor beta (TGF-β) to enhance osteogenic efficiency of the latter^8-11). Besides, researchers developed new scaffolds that can alleviate the osteogenesis-inhibitory effects of bFGF¹²⁾. We reviewed our own experiments, the contrary between repeated operations may rise from the instable and uncontrollable release of bFGF from the nHAP/ COL scaffolds. We plan to improve the preparation process to achieve precise release of bFGF, which can realize repeatability of the experiments. Under these circumstances, we believe that the most responsible course of action is to withdraw this current paper. We sincerely apologize to the scientific community for any inconvenience resulted from the publication and withdrawal this article.</p>