For the treatment of ununited fractures, we developed a system of delivering magnetic labelled mesenchymal stromal cells (MSCs) using an extracorporeal magnetic device. In this study, we transplanted ferucarbotran-labelled and luciferase-positive bone marrow-derived MSCs into a non-healing femoral fracture rat model in the presence of a magnetic field. The biological fate of the transplanted MSCs was observed using luciferase-based bioluminescence imaging and we found that the number of MSC derived photons increased from day one to day three and thereafter decreased over time. The magnetic cell delivery system induced the accumulation of photons at the fracture site, while also retaining higher photon intensity from day three to week four. Furthermore, radiological and histological findings suggested improved callus formation and endochondral ossification. We therefore believe that this delivery system may be a promising option for bone regeneration.
- Fracture healing
- Mesenchymal stromal cell
- Magnetic cell delivery system
- Bioluminescence imaging
- In vivo
This study was supported by a Grant-in-Aid to Professor M. Ochi for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology-Japan (No. 21249079). The authors are thankful to the personnel in the National BioResource Project for the Rat in Japan for providing LEW-Tg(Gt)ROSA)26Sor-luc)11Jmsk and LEW-Tg(Gt(ROSA)26Sor-lacZ)44Jmsk.
The authors would like to thank Professor J. Tanaka at department of epidemiology, infectious disease control and prevention, Hiroshima University for providing help with the statistical analysis.
No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.
- Received October 18, 2011.
- Accepted March 27, 2012.
- ©2012 British Editorial Society of Bone and Joint Surgery