TiO₂ nanoparticles can selectively bind CXCL8 impacting on neutrophil chemotaxis

The interaction between TiO₂ nanoparticles (NPs) and inflammatory cytokines, including CXCL8, a clinically relevant pro-inflammatory chemokine was investigated. TiO₂ is present in tissues adjacent to failing implanted Ti (titanium) devices. TiO₂ NPs were shown to bind to CXCL8 in vitro, causing perturbation of quantification of CXCL8 by ELISA, in both simple and complex protein panels, in a dose-dependent manner. Binding between TiO₂ NPs and CXCL8 was demonstrated by protein gel electrophoresis. TiO₂ NPs were also shown to inactivate the chemoattractant property of CXCL8 in a dose-dependent manner, suggesting that the binding between TiO₂ NPs and CXCL8 is likely to be clinically relevant. The results of this study disputed the applicability of detection of CXCL8 by ELISA in systems where TiO₂ NPs were present. Clinically, the disruption of chemotaxis of neutrophils in response to CXCL8 in the presence of TiO₂ might mean a hampered immune response to inflammation in tissues containing TiO₂ NPs.