Glucosamine/platelet-rich plasma/bone marrow MSC-loaded GelMA hydrogel supports cartilage endplate repair in mice and is associated with reduced inflammation- and oxidative stress-related readouts.

OBJECTIVE

In this study, we developed a gelatin methacryloyl (GelMA) hydrogel composite for the simultaneous delivery of glucosamine (GlcN), platelet-rich plasma (PRP), and bone marrow-derived mesenchymal stem cells (BMMSCs). We systematically investigated its effects on cartilage endplate (CEP) cell behavior, inflammation, and oxidative stress, and evaluated its reparative efficacy in a murine caudal CEP injury model.

METHODS

GlcN/PRP/BMMSC@GelMA was fabricated and comprehensively characterized in terms of its microarchitecture, compressive and rheological properties, enzymatic degradability, swelling, and the sustained release profile of GlcN and platelet-derived growth factor (PDGF). Additionally, primary CEP cells were treated with either GelMA or GlcN/PRP/BMMSC@GelMA to evaluate cell viability, proliferation, apoptosis, and the expression of chondrogenic markers (COL2A1, ACAN, and SOX9) using RT-qPCR and Western blot. Under lipopolysaccharide (LPS) challenge, cytokines (IL-1β, IL-6, TNF-α, IL-10) were quantified using ELISA. Under H2O2 exposure, reactive oxygen species (ROS) levels and oxidative stress markers (MDA, SOD, GSH) were assessed. In vivo, male BALB/c-nu nude mice underwent caudal disc puncture at the Co5/6 level using a 30G needle, followed by intradiscal injection of either GelMA or GlcN/PRP/BMMSC@GelMA. Tissue analyses were performed at 8 weeks post-procedure.

RESULTS

The composite formed a stable three-dimensional network with higher elastic and storage moduli than GelMA alone and supported the sustained release of GlcN and PDGF. The composite also improved CEP cell viability and proliferation, reduced apoptosis, and increased the expression of collagen II, aggrecan, and SOX9. In addition, it reduced LPS-induced inflammatory cytokines and mitigated H2O2-induced oxidative stress-related changes in vitro. In vivo, treatment was associated with improved CEP structural continuity, higher cartilage-related marker expression, and favorable inflammation- and oxidative stress-related readouts.

CONCLUSION

GlcN/PRP/BMMSC@GelMA showed favorable in vitro and in vivo effects and supports the therapeutic potential of this combined local delivery platform for CEP repair.