Facile sonochemically-assisted bioengineering of titanium dioxide nanoparticles and deciphering their potential in treating breast and lung cancers: biological, molecular, and computational-based investigations.

Combining sonochemistry with phytochemistry is a modern trend in the biosynthesis of metallic nanoparticles (NPs), which contributes to the sustainability of chemical processes and minimizes hazardous effects. Herein, titanium dioxide (TiO 2 ) NPs were bioengineered using a novel and facile ultrasound-assisted approach utilizing the greenly extracted essential oil of Ocimum basilicum . FTIR and UV-Vis spectrophotometry were used to confirm the formation of TiO 2 NPs. The X-ray diffraction (XRD) analysis showed the crystalline nature of TiO 2 NPs. TEM analysis revealed the spherical morphology of the NPs with sizes ranging from 5.55 to 13.89 nm. Energy-dispersive X-ray (EDX) confirmed the purity of the greenly synthesized NPs. TiO 2 NPs demonstrated outstanding antitumor activity against breast (MCF-7) and lung (A-549) cancer cells with estimated IC 50 values of 1.73 and 4.79 μg mL -1 . The TiO 2 NPs were cytocompatible to normal cells (MCF-10A) with a selectivity index (SI) of 8.77 for breast and 3.17 for lung cancer. Biological assays revealed a promising potential for TiO 2 NPs to induce apoptosis and arrest cells at the sub-G1 phase of the cell cycle phase in both cancer cell lines. Molecular investigations showed the ability of TiO 2 NPs to increase apoptotic genes' expression (Bak and Bax) and their profound ability to elevate the expression of apoptotic proteins (caspases 3 and 7). Molecular docking demonstrated strong binding interactions for TiO 2 NPs with caspase 3 and EGFR-TK targets. In conclusion, the greenly synthesized TiO 2 NPs exhibited potent antitumor activity and mitochondrion-based cell death against breast and lung cancer cell lines while maintaining cytocompatibility against normal cells.