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Journal of Nanomaterials
Volume 2013, Article ID 506593, 8 pages
Research Article

The Use of Injectable Chitosan/Nanohydroxyapatite/Collagen Composites with Bone Marrow Mesenchymal Stem Cells to Promote Ectopic Bone Formation In Vivo

1Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou 510282, China
2The Second Clinical Medical College of Southern Medical University, Guangzhou 510282, China
3Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
4Department of Radiology, Zhujiang Hospital of Southern Medical University, Guangzhou 510282, China
5Department of Ultrasonic Diagnosis, Zhujiang Hospital of Southern Medical University, Guangzhou 510282, China

Received 13 June 2013; Accepted 14 August 2013

Academic Editor: Shuming Zhang

Copyright © 2013 Bo Yu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The aim of this study was to evaluate ectopic in vivo bone formation with or without rat bone mesenchymal stem cells (rBMSCs) of an injectable Chitosan/Nanohydroxyapatite/Collagen (CS/nHAC) composite. The CS/nHAC composites were injected subcutaneously into the backs of Wistar rats with freshly loaded rBMSCs at a density of  cells/mL, and the CS/nHAC composites without cells were used as negative controls. New bone formation, degradation of composites, and degree of calcification were evaluated by Computed Tomography (CT) and three-dimensional (3D) CT reconstruction. Histological evaluations were performed to further assess bone structure and extracellular matrix by HE and Masson staining. The inflammatory reactions related to osteogenesis were also investigated in the present study. In comparison with the CS/nHAC composites, this study revealed that CS/nHAC/rBMSCs composites showed relatively higher percentage of calcification, better establishment of ECM, and less degradation rate. Meanwhile, different extents of inflammatory reactions were also observed in the CS/nHAC and CS/nHAC/rBMSCs explants at 2 and 4 weeks after implantation. Altogether, CS/nHAC/rBMSCs composites are superior to CS/nHAC composites in ectopic bone formation. In conclusion, the rBMSCs-seeded CS/nHAC composites may be beneficial to enhancing ectopic bone formation in vivo.