Application of Endogenous Stem Cells in the Repair of Annulus Fibrosus Injury of Intervertebral Discs.

Intervertebral disc degeneration (IVDD), a major contributor to chronic low back pain (LBP), involves progressive extracellular matrix (ECM) degradation and limited self-repair. Current therapies alleviate symptoms but fail to halt degeneration, driving interest in endogenous stem cell-based regeneration. Endogenous stem/progenitor cells within disc niches exhibit regenerative potential through ECM synthesis, anti-inflammatory signaling, and exosomal miRNA-mediated repair. Preclinical studies highlight mesenchymal stem cell (MSC) transplantation and reprogramed induced pluripotent stem cells (iPSCs) in restoring disc hydration and reducing pain, while early clinical trials report symptomatic relief (e.g., 70% pain reduction) but incomplete structural recovery. Challenges include the disc's hostile microenvironment (hypoxia and nutrient deprivation), age-related depletion of endogenous stem/progenitor cells, and impaired cell homing under mechanical stress. Emerging strategies target epigenetic modulation, biomimetic scaffolds, and combination therapies to enhance cell survival and integration. Despite promising preclinical outcomes, clinical translation requires overcoming microenvironmental barriers and refining delivery systems. Future efforts should prioritize large-animal validation and biomarker-guided approaches to bridge the gap between experimental success and therapeutic application.