Fig. 5.

a-c. Relative gene expression levels per treatment. The NaCl (sham) treatment in nucleus pulposus (NP) tissue is set at 1. a Relative gene expression levels of ADAMTS5 were significantly upregulated in the NP samples treated with the celecoxib (CXB) bolus (CXB 7.7 μM) and the CXB-loaded hydrogel (CR + CXB 7.7 μM) compared with the unloaded hydrogel (CR). b Gene expression levels ACAN, COL2A1, COL1A1 did not significantly differ between treatments. c BCL2 expression levels were significantly downregulated in the CXB-loaded hydrogel compared with the sham (NaCl). Data are expressed as n-fold changes ± standard deviation. d and e Representative histological images of early degenerated canine NP injected with NaCl (d) or a 770 μM celecoxib (CXB)-loaded pNIPAAM MgFe hydrogel (e) stained with a COX-2 antibody and counterstained with hematoxylin. No significant differences were found between the injected treatments. Chondrocyte-like cell (asterisk) density is increased, and small size clones are present (arrow), indicative of early IVD degeneration. None of the cells in these NPs demonstrated positive staining for the COX-2 antibody. Treatments: NaCl = NaCl (sham); CXB 7.7 μM = celecoxib bolus; CR = unloaded pNIPAAM MgFe-LDH hydrogel; CR + CXB 7.7 μM = pNIPAAM MgFe-LDH hydrogel loaded with 7.7 μM CXB). *Indicates significant difference at a 99 % confidence level. ACAN aggrecan, ADAMTS5 a disintegrin and metalloproteinase with thrombospondin motifs 5, BCL2 B-cell lymphoma 2, COL1A1 collagen type 1 alpha 1, COL2A1 collagen type 2 alpha 1, COX cyclooxygenase, IVD intervertebral disc, pNIPAAM poly-N-isopropylacrylamide