ADVANCED BIOREACTOR STUDIES OF REGION-SPECIFIC RESPONSE IN THE INTERVERTEBRAL DISC TO COMPRESSION, FLEXION/EXTENSION, AND TORSION

• DOI: 10.1302/1358-992x.2024.2.116
• Publication Date: 2024-01-02T16:19:45Z
• Authors: A. Šećerović; A. Ristaniemi; F. Crivelli; S. Heub; G. Weder; S.J. Ferguson; D. Ledroit; S. Grad
• Keywords: Intervertebral Disc; Ex vivo

Intervertebral disc (IVD) degeneration is inadequately understood due to the lack of in vitro systems that fully mimic mechanical and biological complexity this organ. We have recently made an advancement by developing a bioreactor able simulate physiological, multiaxial IVD loading maintain environment ex vivo models [1]. To validate new system, we simulated natural spine movement 12 bovine IVDs under combination static compression (0.1 MPa), cyclic flexion/extension (±3˚, ±6˚ or 0-6˚) torsion (±2˚, ±4˚ 0-4˚) for more than 10’000 (0.2 Hz) 100’000 (1 cycles over 14 days. A higher number increased release glycosaminoglycans nitric oxide, as inflammation marker, whereas fewer maintained these two factors at physiological levels. All applied protocols upregulated expression MMP13 outermost annulus fibrosus (AF), indicating collagen degradation response. This was supported fissures observed AF after longer duration. Increasing induced high cell death nucleus pulposus inner AF, while with cycles, viability all regions, irrespective magnitude rotation. Less frequent maintains homeostasis initiates degenerative profile. Specifically, morphological molecular changes were localized which can be associated combined torsion. More region-specific extracellular matrix molecules from innermost likely exposure compression. Altogether, demonstrated advantages study response IVD, will allow profound investigation different combinations motions.