Aluminium oxide nanoparticles induce structural changes in tau and cytotoxicity of the neuroblastoma cell line.

The application of nanomaterials in the healthy system may induce some neurodegenerative diseases initiated by tau folding and neuronal cell death. Herein, aluminium oxide nanoparticles (AlO NPs) were synthesized and characterized by XRD, TEM, DLS and zeta potential investigations. Afterwards, the interaction of AlO NPs with tau protein was investigated by fluorescence and CD spectroscopic methods. The molecular docking and molecular dynamic were also run to explore the binding site and conformational changes of tau after interaction with AlO cluster. Moreover, the MTT, LDH, caspase-9/-3 and flow cytometry assays were done to explore the AlO NPs-induced cytotoxicity against SH-SY5Y cells. It was revealed that AlO NPs bind to tau protein and form a static complex and fold the structure of tau toward a more packed structure. Molecular docking and molecular dynamic investigations revealed that NPs bind to the hydrophilic residues of the tau segments and promote some marginal structural folding of tau segment. The cellular assays displayed that AlO NPs can elicit cell mortality through membrane leakage, caspase-9/-3 activations, and induction of both apoptosis and necrosis. This data may indicate that NPs can induce some adverse effects on the biological systems.