213. Study comparing NTG-101, a growth factor-based therapy with mesenchymal stem cell (MSC) based treatment of degenerative disc disease (DDD) in pre-clinical rodent model

BACKGROUND CONTEXT Currently there is significant interest in the use of cellular therapies (such as stem cells) to treat degenerative disc disease (DDD). We recently explored the potential use of bone marrow derived stem cells (BMSCs) and cartilage-derived stem cells (CDSCs) in a small animal model of DDD as compared to our recently developed molecular therapy ‘NTG-101’. PURPOSE To compare the therapeutic efficacy of NTG-101 with BMSCs or CDSCs to treat DDD in rodent model. STUDY DESIGN/SETTING In vivo laboratory experimentation involving female Wistar rats aged 12-weeks. PATIENT SAMPLE No human subjects. Animal Care approved study involving female Wistar rats using validated rat-tail injury and injection model. OUTCOME MEASURES Histology, immunohistochemistry, Western blotting, gene expression. METHODS CDSCs were derived from the tibial and femoral plateaus of Wistar rats and sphere forming cells were passaged further in serum free, stem cell specific media. BMSCs were obtained from the femurs of these animals and cultured as adherent cells in media containing 8% fetal bovine serum (FBS) following standard protocols. Stemness was confirmed by differentiation into multiple lineages. In parallel, we induced DDD in caudal intervertebral discs (IVDs) of 12 weeks old Wistar rats (N=30) using image-guided needle puncture injury. Ten weeks later, animals were randomized in six treatment groups (n=5 animals/group) and received an intradiscal injection (8µl) containing:G1-phosphate buffered saline (PBS, 1X, pH=7.2); G2-NTG-101(1X);G3-CDSCs (150,000 cells/disc) suspended in PBS; G4-BMSCs (150,000 cells/disc) suspended in PBS;G5-CDSCs (150,000 cells/disc) suspended in NTG-101(1X); G6-BMSCs (150,000 cells/disc) suspended in NTG-101(1X). At the end of experiment (ie, 10 weeks post-injection, 20 weeks post-injury), animals were humanely euthanized and IVDs were harvested for histology, immunohistochemistry and Western blotting. RESULTS Gene expression analysis using quantitative real time PCR confirmed expression of pluripotency (Oct4, Nanog, Sox2) and mesenchymal stem cell surface markers (CD29, CD44, CD90, CD105, CD133, CD166) in all stem cells. CDSC and BMSCs differentiation into chondrogenic, osteogenic and adipogenic lineages was confirmed, thereby validating their stemness potential. Discs injected with PBS developed a degenerative phenotype with the loss of NP morphology, cellularity and the development of a degenerative fibrocartilaginous phenotype. On the other hand, IVDs injected with NTG-101 or CDSCs alone showed a significant recovery. The morphology and cellularity of discs injected with BMSCs alone or in combination with NTG-101 was not significantly different from those discs injected with PBS. NTG-101 injected discs showed a healthy NP rich in notochordal and resident stem cells as revealed by nuclear Brachyury and Oct4 respectively, whereas discs injected with stem cells alone or stem cells plus NTG-101 did not. CONCLUSIONS Our preclinical data demonstrated that single intradiscal injection of NTG-101 is a superior and effective therapy for regeneration of IVD-NP in comparison to mesenchymal stem cell-based therapies for treatment of DDD. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.