Articular cartilage repair using an intra-articular magnet and synovium-derived cells

J Orthop Res. 2011 Apr;29(4):531-8. doi: 10.1002/jor.21267. Epub 2010 Nov 9.


The purpose of this study was to investigate the chondrogenic potential of magnetically labeled synovium-derived cells (M-SDCs) and examine whether M-SDCs could repair the articular cartilage using an intra-articular magnet after delivery to the lesion. Synovium-derived cells (SDCs) were cultured from the synovium of a rat knee, and were magnetically labeled with ferumoxides. M-SDCs were examined with a transmission electron microscope. A pellet culture system was used to evaluate the chondrogenic potential of M-SDCs in a magnetic field. In a rat model, allogeneic M-SDCs were injected into the knee after we made an osteochondral defect on the patellar groove and implanted an intra-articular magnet at the bottom of the defect. We histologically examined the defects at 48 h, 4 weeks, 8 weeks, and 12 weeks after treatment. Electron microscopy showed the transfection of ferumoxides into SDCs. The pellet cultures revealed the chondrogenic potential of M-SDCs in a magnetic field. M-SDCs accumulated in the osteochondral defect at 48 h after treatment, and we confirmed the regeneration of the articular cartilage at 4 weeks, 8 weeks, and 12 weeks after treatment using an intra-articular magnet. We demonstrated that articular cartilage defects could be repaired using an intra-articular magnet and M-SDCs. We believe that this system will be useful to repair human articular cartilage defects.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone Regeneration
  • Cartilage, Articular / injuries*
  • Cartilage, Articular / surgery
  • Cell Transplantation / methods*
  • Dextrans
  • Injections, Intra-Articular
  • Magnetics
  • Magnetite Nanoparticles
  • Mesenchymal Stem Cell Transplantation*
  • Mesenchymal Stem Cells / metabolism
  • Mesenchymal Stem Cells / ultrastructure
  • Patella
  • Rats
  • Rats, Sprague-Dawley
  • Stifle / injuries
  • Stifle / pathology*
  • Stifle / surgery
  • Synovial Membrane / cytology*
  • Synovial Membrane / metabolism
  • Wound Healing / physiology


  • Dextrans
  • Magnetite Nanoparticles
  • ferumoxides