Protein Binding Effects of Dopamine Coated Titanium Dioxide Shell Nanoparticles

Non-targeted nanoparticles are capable of entering cells, passing through different subcellular compartments and accumulating on their surface a protein corona that changes over time. In this study, we used metal oxide nanoparticles with iron-oxide core covered with titanium dioxide shell (Fe₃O₄@TiO₂), with a single layer of covalently bound dopamine covering the nanoparticle surface. Mixing nanoparticles with cellular protein isolates showed that these nanoparticles can form complexes with numerous cellular proteins. The addition of non-toxic quantities of nanoparticles to HeLa cell culture resulted in their non-specific uptake and accumulation of protein corona on nanoparticle surface. TfRC, Hsp90 and PARP were followed as representative protein components of nanoparticle corona; each protein bound to nanoparticles with different affinity. The presence of nanoparticles in cells also mildly modulated gene expression on the level of mRNA. In conclusion, cells exposed to non-targeted nanoparticles show subtle but numerous changes that are consistent from one experiment to another.