Decellularized porcine annulus fibrosus to prepare a natural scaffold for intervertebral disc tissue engineering

Intervertebral disc (IVD) plays an important role to sustain weight and absorb shocks in human body. Low back pain associated with the disc degeneration causes lots of inconvenience and economic burden. Currently, the treatments of disc degeneration tend to be traditional and conservative. Treatments, such as physical therapy, discectomy, spinal fusion and drug treatment, had focused on relieving mechanical pain instead of repairing and regenerating the disc. Tissue engineering has attracted much attention and aim to be a effective method that could regenerate the IVD. Repairing the annulus fibrosus (AF) is the most significant matter in disc regeneration treatments. The gelatinous nucleus pulposus (NP) can’t exist steadily in the disc if the lack of AF. Therefore, taking priority to repair the AF enables the disc regeneration treatment easier.
In this study, we took the decellularized techniques which combine physical, chemical and enzyme methods. We decellularized porcine AFs and created AF scaffolds for IVD tissue engineering. Since the xenotransplantation generated many immune problems, we not only try to reduce the cells and immune substances but retain the extracellular matrix (ECM). In this study, we evaluated different freeze-thaw temperatures, various chemical detergents and different decellularized time, followed by optimizing the best decellularizing method.

Using the optimized decellularizing process, we found that the DNA content 85% and α-Gal content decreased 85% and 75%. Furthermore, we could maintain 94% of GAGs contents and 98% of collagen contents. The MTS assay revealed that the decellularized AFs had no cytoxicity for cell culture. And there were no significant mechanical differences between fresh and decellularized annulus fibrosus. These results suggested that the decellularized porcine AFs have great development for IVD repair and regeneration.