Grant: Project Grant

Low back pain affects 50% of Canadians with direct medical costs of 6-12 billion annually. Its major cause, intervertebral disc (IVD) degeneration, often needs surgical interventions at advanced disease stages. Existing treatment options include spine fusion, total disc replacement, repair of nucleus pulposus (NP; a substructure of IVD). Whereas spine fusion causes degeneration in adjacent spinal segments and total disc replacement involves complicated surgery and high failure rates, repair of the total or partial NP is appealing because it can minimize tissue removal and reduce surgical and post-surgical complications. However, the NP repair has long limited by extrusion or subsidence of the implants that are poorly integrated with adjacent tissues in the disc. It is due to the poor adhesion property of the implants like hydrogels and their limited ability to integrate with the body. We recently developed bioinspired hydrogel adhesives that can achieve superior tissue-adhesion performance on various wet dynamic tissues. We also established a tissue-engineering strategy of NP cell delivery to prompt IVD healing. The advances highlight an unprecedented opportunity for NP repair by combining the novel adhesives and cell delivery strategies. We hypothesize that this strategy could enable immediate and long-term integration of the implants with the body by tissue adhesion and cell activities, potentially transforming the IVD repair. This project includes four Aims: (1) Benchmarking mechanical properties of IVD; (2) Developing injectable biodegradable tough IVD glues; (3) Engineering the IVD glues with optimal viscoelastic and cell-adhesion properties; (4) Functional analysis with a whole disc culture model with bioreactors. This project will greatly advance the science of IVD biomechanics and biology, overcome limitations of existing NP implants, improve surgical outcomes of NP repair and quality of life of millions of Canadians living with low back pain.