Formation of potential titanium antigens based on protein binding to titanium dioxide nanoparticles

Carmen Irina Vamanu¹, Paul Johan Høl², Zouhir Ekeland Allouni², Said Elsayed³, Nils Roar Gjerdet¹

¹Departments of Oral Sciences – Dental Biomaterials, Faculty of Dentistry, University of Bergen, Bergen, Norway; ²Orthopedic Biomaterials, Helse Bergen Haukeland University Hospital, Bergen, Norway; ³Department of Medicine, University of Bergen, Bergen, Norway

Abstract: Degradation products of titanium implants include free ions, organo-metallic complexes, and particles, ranging from nano to macro sizes. The biological effects, especially of nanoparticles, is yet unknown. The main objective of this study was to develop Ti-protein antigens in physiological solutions that can be used in testing of cellular responses. For this purpose, 0.1% TiO₂ nanoparticles less than 100 nm were mixed with human serum albumin (HSA), 0.1% and 1%, in cell culture medium (DMEM, pH 7.2). The Ti concentrations in the resulting solutions were analyzed by inductively coupled plasma mass spectrometry. The stability of the nanoparticles in suspension was analyzed by UV-vis spectrophotometer and Dynamic Light Scattering. The concentration of Ti in suspension was dependent on the presence and concentration of HSA. Albumin prevented high aggregation rate of TiO₂ nanoparticles in cell culture medium. It is shown that nano TiO₂-protein stable aggregates can be produced under physiological conditions at high concentrations, and are candidates for use in cellular tests.

Keywords: titanium, nanoparticle, hypersensitivity to Ti