BMP-2 gene activated muscle tissue fragments for osteochondral defect regeneration in the rabbit knee

J Gene Med. 2017 Sep;19(9-10). doi: 10.1002/jgm.2972. Epub 2017 Sep 22.


Background: Previously published data indicate that BMP-2 gene activated muscle tissue grafts can repair large bone defects in rats. This innovative abbreviated ex vivo gene therapy is appealing because it does not require elaborative and time-consuming extraction and expansion of cells. Hence, in the present study, we evaluated the potential of this expedited tissue engineering approach for regenerating osteochondral defects in rabbits.

Methods: Autologous muscle tissue grafts from female White New Zealand rabbits were directly transduced with an adenoviral BMP-2 vector or remained unmodified. Osteochondral defects in the medial condyle of rabbit knees were treated with either BMP-2 activated muscle tissue implants or unmodified muscle tissue or remained empty. After 13 weeks, repair of osteochondral defects was examined by biomechanical indentation testing and by histology/imunohistochemistry applying an extended O'Driscoll scoring system and histomorphometry.

Results: Biomechanical investigations revealed a trend towards slightly improved mechanical properties of the group receiving BMP-2 activated muscle tissue compared to unmodified muscle treatment and empty defect controls. However, a statistically significant difference was noted only between BMP-2 muscle and unmodified muscle treatment. Also, histological evaluation resulted in slightly higher histological scores and improved collagen I/II ratio without statistical significance in the BMP-2 treatment group. Histomorphometry indicated enhanced repair of subchondral bone after treatment with BMP-2 muscle, with a significantly larger bone area compared to untreated defects.

Conclusions: Gene activated muscle tissue grafts showed potential for osteochondral defect repair. There is room for improvement via the use of appropriate growth factor combinations.

Keywords: BMP-2; biomechanical indentation testing; cartilage repair; gene therapy; muscle tissue; osteochondral defect.

MeSH terms

  • Animals
  • Bone Morphogenetic Protein 2 / genetics*
  • Bone Morphogenetic Protein 2 / metabolism
  • Bone Regeneration / genetics*
  • Cell Line
  • Chondrogenesis / genetics*
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Gene Expression
  • Humans
  • Immunohistochemistry
  • Knee Joint*
  • Models, Animal
  • Muscle, Skeletal / metabolism*
  • Muscle, Skeletal / transplantation
  • Rabbits


  • Bone Morphogenetic Protein 2