Comparison of the Therapeutic Effects of Gold Nanoclusters and Gold Nanoparticles on Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by synovial inflammation and progressive cartilage and bone damage. In our previous studies, we found that Au clusters using glutathione as a template (GACs) produced profound anti-inflammatory effects in vitro on lipopolysaccharide (LPS)-induced inflammation in mouse macrophage RAW 264.7 cells and type II collagen-induced rat RA in vivo. In this study, we examined whether the template for Au clusters synthesis has an effect on its anti-inflammatory effect and whether Au nanoparticles with larger particle diameter produce the same anti-inflammatory effect. We synthesized Au clusters with bovine serum albumin (BSA) as a template (BACs), Au clusters with glutathione (GSH) as a template (GACs), and Au nanoparticles with glutathione as a template (GANs) and compared their anti-inflammatory effects in vitro and in vivo. These three Au nanomaterials can inhibit the production of lipopolysaccharide (LPS)-induced proinflammatory mediators and ameliorate type II collagen-induced rat RA. However, although the three Au nanomaterials produced similar anti-inflammatory effects, the GANs with larger particle sizes were less stable in vivo and accumulated in the peritoneum after intraperitoneal injection, resulting in poor absorption in vivo. The BACs showed relatively high liver accumulation due to the larger molecular weight of the outer shell. Therefore, we believe that the GACs are potential reliable nanodrugs for the treatment of RA.