2025 Volume No 50 – pages 1-19
Title: A novel intervertebral disc bioreactor system for studying clinically based active dynamic unloading combining biological and biomechanical outcomes |
Authors: A Soubrier, H Kasper, G Miklosic, M Alini, I Jonkers, S Grad |
Address: AO Research Institute Davos, 7270 Davos Platz, Switzerland |
E-mail: sibylle.grad at aofoundation.org |
Abstract: Background: Intervertebral disc (IVD) degeneration relies on a complex interrelated cascade of biological and mechanical processes in which loss of water content plays an important role. Despite the positive effects of unloading on clinical outcome parameters and IVD hydration, the biological and mechanical changes induced by these protocols remain poorly understood. Moreover, no bioreactor setup allows assessment of clinically relevant IVD unloading ex vivo. Consequently, the purposes of this study were (1) to develop a bioreactor system for clinically based active dynamic unloading of IVDs through tension, and (2) to evaluate unloading mechanobiology of undegenerated bovine tail IVDs as proof of concept. Methods: We developed a bioreactor setup for active dynamic unloading of bovine tail discs. After bioreactor culture, we assessed biological and biomechanical parameters, including sulfated glycosaminoglycan (sGAG) release in the medium, water/sGAG ratio, gene expression and cell viability as well as IVD height, neutral zone, slope and area under the curve. Results: The developed bioreactor system was precise and reliable in terms of loading, and the outcomes demonstrated technical feasibility. The biological and biomechanical outcomes showed consistency, as the biological readouts indicate higher water content and an anti-catabolic response of the IVDs after active dynamic unloading while the biomechanical outcomes suggest a higher water content and improved mechanical resistance. Conclusions: This study outlines the development of a unique ex vivo culture system for analysing biology and biomechanics of clinically relevant active dynamic unloading of IVDs and opens the way for studying movement based regenerative protocols for degenerated IVDs. |
Keywords: Intervertebral disc, mechanobiology, traction, unloading, bioreactor, bovine organ model. |
Publication date: 8th April 2025 |
Copyright policy: © 2025 The Author(s). Published by Forum Multimedia Publishing, LLC. This article is distributed in accordance with Creative Commons Attribution Licence (http://creativecommons.org/licenses/by/4.0/). |
Article download: Pages 1-19 (PDF file) |
