IPN nanocomposite scaffolds based on GelMA-alginate with modified super-paramagnetic iron oxide for cartilage tissue engineering.

Repairing articular cartilage defects remains a significant challenge due to the avascular nature of the tissue, which impedes cartilage regeneration. Gelatin-based hydrogels, including gelatin methacryloyl (GelMA) and alginate, are widely used in tissue engineering for their favorable biological properties. However, their mechanical strength frequently falls short. This study examines the influence of superparamagnetic iron oxide nanoparticles (SPIONs) at concentrations of 0.5 %, 0.75 %, and 1 % on the properties of an interpenetrating polymeric network (IPN) comprising GelMA and sodium alginate (SA). The hydrogels were analyzed for their physicomechanical properties, rheological behavior, and biological responses, including fibroblast cell adhesion (L929) and MTT assay results. The presence of SPIONs significantly decreased swelling and degradation by 66 % and 28 %, respectively. Furthermore, the compressive strength, modulus, and shear-thinning behavior improved by 63 %, 61 %, and 57 %, respectively. No cytotoxicity was observed, and cell proliferation was favorable under a magnetic field. The MRI results validated the efficacy of SPIONs as a T2 contrast agent. Notably, the GelMA/SA hydrogel containing 0.75 % SPIONs exhibited optimal mechanical properties, highlighting its potential as a biomaterial for cartilage tissue engineering.