Annular fibrotic (AF) damage plays a key role in intervertebral disc degeneration (IVDD), with oxidative stress and extracellular matrix (ECM) imbalance being major pathogenic factors. However, effective repair methods are limited. This study developed an injectable photothermal hydrogel Mn3O4@ChS-HA, composed of dopamine-grafted chondroitin sulfate (dop-OChS), adipic dihydrazide-modified hyaluronic acid (ADH-HA), and Mn3O4 nanoparticles,to repair AF damage. Mn3O4@ChS-HA mimics the native intervertebral disc environment, exhibiting excellent mechanical properties and strong adhesion to AF defect sites, while also supporting the long-term retention of Mn3O4 nanoparticles. Mn3O4 nanoparticles demonstrate catalytic characteristics similar to superoxide dismutase, catalase, and glutathione peroxidase, effectively scavenging reactive oxygen species and regulating ECM metabolism. In vitro and in vivo studies have shown that Mn3O4@ChS-HA significantly inhibits cell apoptosis,Delays cellular aging, reduces inflammation, promotes autophagy, and facilitates atrial fibrillation repair. The hydrogel can also restore intervertebral disc height and maintain ECM integrity in a rat model of atrial fibrillation injury. Mild photothermal therapy (MPTT) further enhances these effects, supporting tissue regeneration and delaying the progression of IVDD. The MPTT-nanozyme-hydrogel system Mn3O4@ChS-HA exhibits multiple biological functions by regulating redox homeostasis and promoting tissue repair, highlighting the potential of this approach as a promising strategy for IVDD treatment.

Original link

Advanced Functional Materials ( IF 19 )

Pub Date : 2025-06-20

DOI: 10.1002/adfm.202422817

Yangyang Chen,  Chan Xue,  Feifei Ni,  Binwu Hu,  Miaoheng Yan,  He Zhang,  Yuxiang Hu,  Xiaoyao Peng,  Guangfang Li,  Yu Han,  Hongjian Liu,  Zengwu Shao,  Qin Wang,  Yulong Wei