Date of Award
Master of Science (MS)
Annually over 3 million people suffer from intervertebral disc (IVD) herniation (IVDH)1 and approximately 500,000 discectomies are performed in the United States alone. Within one-year post-operation, up to 15% of patients must undergo a second discectomy or spinal reconstruction due to re-herniation2. One potential method to overcome limitations associated with discectomies is to develop tissue engineered constructs to augment the surgical procedure. Previously two novel scaffolds have been created by our lab: an annulus fibrosus repair patch (AFRP) and acellular bovine nucleus pulposus (ABNP); however, these constructs require extensive testing before implementation in humans. Therefore, the purpose of the work herein was to create an ex vivo IVDH bovine organ culture that mimics key features of the herniated IVD microenvironment that can be used to assess the efficacy of scaffolds developed for IVDH repair and regeneration.
Fresh oxtails were acquired from a local abattoir and bovine IVDs (bIVDs) were isolated and separated into three groups. The Control group did not undergo a discectomy and were without the presence of additional inflammatory cytokines. The Injury group underwent a discectomy, using a 6mm biopsy and surgical rongeurs, and were cultured in the presence of 250 ρg/mL of both IL-1β and TNF-α. Lastly, the Repair group underwent the same discectomy, but was repaired two days later with the AFRP and ABNP seeded with human amniotic mesenchymal stromal cells (hAMSCs).
Results showed that all three groups maintained cell viability out to 30 days in all key regions of the bIVD. Furthermore, histological analysis showed that the Injury group showed trends of degeneration relative to the Control group such as decreased staining intensity of glycosaminoglycans (GAGs) and distortion of the annulus fibrosus (AF). Alternatively, the Repair group showed each scaffold was histologically like its native counterparts and showed an overall less degenerative state than the Injury. In summary, a viable free swelling of bIVDs was created establishing histological degenerative hallmarks at 30 days while allowing for current tissue engineered scaffolds evaluations.
Krussig, Mario Josef, "Bovine Intervertebral Disc Organ Culture for Assessing Regenerative Therapeutics for Herniation Repair" (2021). All Theses. 3578.