Oxidative stress modulation induced by chitosan-glutathione nanoparticles in chondrocytes.

: The use of nanometric systems to deliver biologically active substances is a successful tool in different fields. In this study, we investigated nanometric systems with antioxidant capacity to modulate events associated with the redox state in human chondrocytes. We used nanoparticles (NPs) prepared with chitosan and glutathione (GSH) and an in vitro model: primary cultures of human chondrocytes were extracted from hyaline cartilage. The cells were exposed to CdCl₂ in the presence or absence of NPs. CdCl₂ is a widely known oxidizing agent. Fluorescence and confocal microscopy showed the location of the NPs within the cells. The results obtained showed that the NPs did not significantly affect cell viability. We studied the antioxidant capacity of the NPs by estimating the GSH, TBARs, and Cell Rox content and the enzymatic activity of glutathione peroxidase (GPx). In vitro assays showed that GSH levels, GPx activity and reactive oxygen species (Cell Rox) levels were modified with both concentrations of NPs, while lipoperoxidation (TBARs) decreased when cells exposed to CdCl₂ were in contact with the NPs. All these results suggest the ability of NPs to modulate the cell redox state in a dose-dependent manner.