Engineering Intervertebral Disc Regeneration: Biomaterials, Cell Sources and Animal Models

Intervertebral disc (IVD) degeneration is an age-related problem triggering chronic spinal issues, such as low back pain and IVD herniation. Standard surgical treatment for such spinal issues is the removal of the degenerated or herniated IVD and fusion of adjacent vertebrae to stabilise the joint and locally decompress the spinal cord and/or nerve roots to relieve pain. However, a key challenge of current surgical strategies is the increasing risk of adjacent segment degeneration due to the disruption of native biomechanics of the functional spinal unit, dominated by the loss of the IVD. In the past two decades, research has focused on developing a number of bioengineering approaches to repair and regenerate the IVD; in particular, tissue engineering of the IVD, using bioscaffolds and stem cells represents a promising area. This review highlights the current tissue engineering approaches utilising biomaterials, animal models and cell sources for IVD regeneration and discusses future opportunities.