Fig. 6.

Molecular mechanism diagrams of PBNPs alleviate ROS in NP cells. The mechanism is divided into three levels. First, antioxidant enzyme‐like PBNPs can directly scavenge extracellular ROS; second, PBNPs can inhibit the ubiquitin‐proteasome degradation of intracellular SOD1, increase the number of mitochondria‐related SOD1 protein and enzyme activity, and eliminate intracellular ROS; third, PBNPs can activate Ras, p53, PI3K Akt, AMPK, and other pathways, directly affecting the transcription of antioxidant enzymes (SOD, GPX, and SIRT). Under these three key mechanisms, PBNPs can improve the antioxidant capacity inside and outside NPs, which further activates the viability of cells, improves the anabolic ability of cells, and reconstructs the ECM of the nucleus pulposus, which rescues ROS‐mediated IVDD in animal models. Reproduced with permission [121]. Copyright 2022, The Authors. Advanced Science published by Wiley-VCH GmbH.