Repair of intervertebral disc degeneration using KLD-12/TGF-β1 fiber gel combined with BMSCs in a rabbit model

The purpose of this study was to examine the repairing effect of KLD-12 polypeptide/TGF-β1 nanofiber gel combined with BMSCs in a rabbit intervertebral disc degeneration model. The rabbit models were divided into four groups after 2 weeks: KLD-12 polypeptide/TGF-β/BMSCs gel (A), normal saline (B), KLD-12 polypeptide/BMSCs gel (C), and no treatment (D). X-ray examination revealed that the %DHI (disc height index) of group A increased from 4 weeks to 24 weeks and that these values were significantly higher than those of groups B and C (P<0.05). A similar trend was observed for the intensity of MRI T2-weighted signal. We observed newborn nucleus pulposus tissue in group A, grayish yellow fibrous hyperplasia in group B, white fibrous hyperplasia in group C; and translucent jelly-like tissue in group D. HE staining scores for groups A, B, C, and D were at levels 1-2, 4-5, 3-4, and 0, respectively. The nucleus pulposus cells in groups A and D were deep dyed with toluidine blue. The gray values for aggrecan and collagen II of group A showed slight increases from 4 weeks to 24 weeks, and these values were significantly higher than those of groups B and C (P<0.05). KLD-12 polypeptide/TGF-β1 nanofiber gel combined with BMSCs plays a role in the repair of degenerative intervertebral disc and promotes the regeneration of the nucleus pulposus tissue in the intervertebral disc in rabbits.