A Protein and Membrane Integrity Study of TiO2 Nanoparticles-Induced Mitochondrial Dysfunction and Prevention by Iron Incorporation.

The paper assessed the toxic effect of titanium dioxide (TiO2) nanoparticles (NPs) on isolated mitochondria and its dysfunction prevention after Iron (Fe) incorporation. TiO2 and Fe content TiO2 NPs were synthesized and characterized using XPS, PL spectroscopy, and TEM. The nanostructure interaction with isolated mitochondria was investigated using circular dichroism (CD) confocal microscopy, flow cytometry, atomic force microscopy (AFM), surface-enhanced Raman spectroscopy (SERS), and FT-IR spectroscopy via nonspecific pathway. Fe content TiO2 NPs helps to control the dissolution rate of parent nanomaterial of TiO2 on the mitochondrial membrane. Confocal micrographs and flow cytometry results confirmed that Rhodamine 123 dye intensity get increased after interaction with Fe content TiO2 NPs which states the integrity of the mitochondrial membrane. AFM results revealed that TiO2 induces the swelling of mitochondrial tubules and also impaired the mitochondrial structure, whereas Fe content TiO2 NPs interaction prevents the impairment of mitochondrial tubules. The denaturation of a membrane protein by TiO2 interactions was observed through CD Spectroscopy. Further, nano-bio-interface study was performed using SERS, through shifting and extinct of peaks affiliated to membrane proteins and lipids. However, Fe content TiO2-treated samples showed a significant increase in the membrane potential of mitochondria via flow cytometry results.