Ti–O based nanomaterials ameliorate experimental autoimmune encephalomyelitis and collagen-induced arthritis

Abstract

Multiple sclerosis (MS) and rheumatoid arthritis (RA) are the most common chronic autoimmune inflammatory diseases that affect the central nervous system and joints respectively. Treatment of autoimmune diseases usually concentrates on alleviating symptoms. High-mobility group box 1 protein (HMGB1) cytokine had been reported to play a key role in autoimmune disorders as HMGB1 levels correlate with active inflammation and neutralizing HMGB1 can rescue various autoimmune diseases. Nano-size titania (TiO₂) is an exceptional multi-functional material that showed several practical applications ranging from pigments in paints, UV light absorbent in sunscreen lotion to coatings on non-fogging surfaces, biomedicine and agriculture. However, the in vivo role of Ti–O based nanomaterials in autoimmune disease models has not been examined. This study was designed to investigate the role of Ti–O based nanomaterials such as H₂Ti₃O₇ nanotubes (TNT) and anatase TiO₂ fine particles (TFP) in well established animal models experimental autoimmune encephalomyelitis (EAE) and collagen induced arthritis (CIA). We showed for the first time that the administration of Ti–O based nanomaterials attenuated clinical signs of pathophysiology and correlated with the reduction of the pro-inflammatory cytokine HMGB1. The clinical signs, histology and HMGB1 secretion data showed the therapeutic role of TNT and TFP in EAE and TNT in CIA. Thus, TNT and TFP have potential applications in specific treatment of MS/RA and this may provide an effective novel therapeutic approach for other autoimmune diseases.