Fig. 1

Image bundle of current state-of-the-art research strategies to treat IDD, described in this review, such as (1) injectable NP hydrogel, (2) minimal invasive scaffold for AF scaffold, (3) full AF scaffold, and (4) biphasic scaffold for total IVD replacement. Permissions: 1 – images used in this scheme were adapted from two articles of Silva-Correia et al. [62, 81]; 2 – images used in this scheme were adapted from Xin et al. [93] under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/); 3 – images used in this scheme were adapted from van Uden et al. [99] © IOP Publishing. Reproduced with permission. All rights reserved; 4 – images used in this scheme were adapted from Choy et al. [95] under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/)