Injectable hydrogels based on biological macromolecules and intervertebral disc-derived stem cells for intervertebral disc degeneration repair: A review.

Intervertebral disc degeneration (IDD) is the fundamental pathological process underlying spinal degenerative diseases. Recent studies on early intervention strategies for delaying and repairing IDD have become a pivotal focus in spinal surgery. Injectable hydrogels synthesized from biological macromolecules, such as polyvinyl alcohol, polyethylene glycol, gelatin, and chitosan, and stem cells have garnered significant attention due to their potential for biomimetic intervertebral disc repair, particularly intervertebral disc-derived stem cells (IVD-SCs). Notably, IVD-SCs exhibit unique tissue-specific characteristics. A comprehensive literature review revealed a limited number of studies investigating the combined application of injectable hydrogels and IVD-SCs for IDD repair. Therefore, we present a comprehensive overview of the development and application of injectable hydrogels and IVD-SCs in IDD repair, detailing their isolation, characterization, clinical translation, associated challenges, and future perspectives. We provide novel insights and directions for advancing future IDD regenerative therapies.