BACKGROUND/CONTEXT: Disc degeneration (DD) is a significant driver of low back pain
and few treatments exist to treat the pain and disability associated with the disease.
PURPOSE: Our group has developed a method to generate therapeutic discogenic cells as a potential
treatment for symptomatic DD. These cells are derived and modified from adult nucleus pulposus
cells. In this study, we evaluated the characteristics, mode of action, and in vivo efficacy and
safety of these cells prior to human clinical testing.
STUDY DESIGN: Privately funded in vitro studies and in vivo preclinical models were used in
this study.
METHODS: Discogenic cells generated from different adult human donors were evaluated for
surface marker expression profile, matrix deposition and tumorigenic potential. Discogenic cells
were then injected subcutaneously into nude mice to assess cell survival and possible extracellular
matrix production in vivo. Finally, a rabbit model of DD was used to evaluate the therapeutic
potential of discogenic cells after disc injury.
RESULTS: We found that discogenic cells have a consistent surface marker profile, are multipotent
for mesenchymal lineages, and produce extracellular matrix consisting of aggrecan, collagen 1
and collagen 2. Cells did not show abnormal karyotype after culturing and did not form tumor-like
aggregates in soft agar. After subcutaneous implantation in a nude mouse model, the human discogenic
cells were found to have generated regions rich with extracellular matrix over the course of 4
months, with no signs of tumorigenicity. Intradiscal injection of human discogenic cells in a rabbit
model of DD caused an increase in disc height and improvement of tissue architecture relative to
control discs or injection of vehicle alone (no cells) with no signs of toxicity.
CONCLUSIONS: This study demonstrates that intradiscal injection of discogenic cells may be a
viable treatment for human degenerative disc disease. The cells produce extracellular matrix that may rebuild the depleting tissue within degenerating discs. Also, the cells do not pose any significant safety concerns.