eCM (Eur Cell Mater / e Cells & Materials) Not-for-profit Open Access
Created by Scientists, for Scientists
 ISSN:1473-2262         NLM:100973416 (link)         DOI:10.22203/eCM

2017   Volume No 33 – pages 1-12

Title: BMP-2-coated mineral coated microparticles improve bone repair in atrophic non-unions

Authors: M Orth, NJ Kruse, BJ Braun, C Scheuer, JH Holstein, A Khalil, X Yu, WL Murphy, T Pohlemann, MW Laschke, MD Menger

Address: Department of Trauma, Hand and Reconstructive Surgery, Saarland University, Kirrberger Strasse 1, D-66421 Homburg/Saar, Germany

E-mail: marcel.orth at

Key Words: Non-union, mineral coated microparticles, BMP-2, bone healing, biocompatibility, mice.

Publication date: January 2nd 2017

Abstract: Atrophic non-unions are a major clinical problem. Mineral coated microparticles (MCM) are electrolyte-coated hydroxyapatite particles that have been shown in vitro to bind growth factors electrostatically and enable a tuneable sustained release. Herein, we studied whether MCM can be used in vivo to apply Bone Morphogenetic Protein-2 (BMP-2) to improve bone repair of atrophic non-unions. For this purpose, atrophic non-unions were induced in femurs of CD-1 mice (n = 48). Animals either received BMP-2-coated MCM (MCM + BMP; n = 16), uncoated MCM (MCM; n = 16) or no MCM (NONE; n = 16). Bone healing was evaluated 2 and 10 weeks postoperatively by micro-computed tomographic (µCT), biomechanical, histomorphometric and immunohistochemical analyses. µCT revealed more bone volume with more highly mineralised bone in MCM + BMP femurs. Femurs of MCM + BMP animals showed a significantly higher bending stiffness compared to other groups. Histomorphometry further demonstrated that the callus of MCM + BMP femurs was larger and contained more bone and less fibrous tissue. After 10 weeks, 7 of 8 MCM + BMP femurs presented with complete osseous bridging, whereas NONE femurs exhibited a non-union rate of 100 %. Of interest, immunohistochemistry could not detect macrophages within the callus, indicating a good biocompatibility of MCM. In conclusion, the local application of BMP-2-coated MCM improved bone healing in a challenging murine non-union model and, thus, should be of clinical interest in the treatment of non-unions.

Article download: Pages 1-12 (PDF file)

Supplementary Video: Video1