Crucial role of the protein corona for the specific targeting of nanoparticles

We aimed to investigate the physicochemical effects of superparamagnetic iron oxide nanoparticles (SPIONs) on the composition of the protein corona and their correspondence toxicological issues. Materials & methods: SPIONs of different sizes and surface charges were exposed to fetal bovine serum. The structure/composition and biological effects of the protein corona-SPION complexes were probed. Results & discussion: The affinity and level of adsorption of specific proteins is strongly dependent on the size and surface charge of the SPIONs. In vivo experiments on the mouse blood-brain barrier model revealed that nontargeted SPIONs containing specific proteins will enter the brain endothelial barrier cells. Conclusion: Some commercially available nanoparticles used for target-specific applications may have unintended uptake in the body (e.g., brain tissue) with potential cytotoxity.