Complex hydrogel for cartilage regeneration and anti-inflammation

With the increasing incidence of osteoarthritis (OA) in elderly patients and the challenges posed by its multifaceted pathogenesis in developing effective treatments, this study explores the effective protein loading mode of Progranulin (PGRN) and its therapeutic potential for treating OA. GelMA hydrogels prepared with different concentrations of PGRN, employing AC-PEG-NHS as a crosslinking agent for drug encapsulation, were used to test the sustained release effect of the composite hydrogel drug delivery system. Additionally, we conducted in vitro assays to investigate the regulatory effects on rat bone marrow mesenchymal atromal cells (BMSCs), chondrocytes, and mouse macrophages - focusing on cell proliferation, and differentiation. For in vivo studies, histological staining techniques were utilized to assess inflammatory cell polarization and cartilage repair in a rat knee injury model. The results demonstrated that PGRN-loaded hydrogels significantly accelerated cell proliferation, enhance differentiation of BMSCs into chondrocytes, maintained a healthy chondrocyte phenotype, and induce M2-type polarization while inhibiting M1-type polarization in macrophages. Histological analyses also showed markedly improved tissue repair in the group treated with GelMA-NHS-PGRN hydrogels. As a result, these GelMA-NHS-PGRN hydrogels present a promising therapeutic approach for OA, potentially mitigating chronic inflammation and facilitating cartilage repair through controlled release of PGRN. Key world PGRN, Osteoarthritis, Anti-inflammatory hydrogels, Cartilage regeneration.