Synergistic effect of TEMPO-coated TiO₂ nanorods for PDT applications in MCF-7 cell line model

This study focuses on the synthesis, characterization, and assessment of the synergistic effect of 2,2,6,6, tetramethylpiperidine-N-oxyl (TEMPO)-coated titanium dioxide nanorods (TiO₂ NRs) for photodynamic therapy (PDT). Firstly, TiO₂ NRs were synthesized by the sol-gel technique. Then, TEMPO was grafted on TiO₂ NRs with the aid of oxoammonium salts. Next, the final product was characterized by applying manifold characterization techniques. X-ray diffraction was used to perform crystallographic analysis; transmission electron microscopy (TEM) was used to conduct morphological analysis; Fourier transform infrared (FTIR) and Raman spectra were recorded to perform molecular fingerprint analysis. Furthermore, experimental and empirical modeling was performed to confirm the suitability of as-prepared samples for PDT applications using (MCF-7 cell line) Human Breast Cancer cell line. Our results revealed that bare TiO₂ NRs did not exhibit a significant response for therapeutic applications compared to TEMPO-conjugated TiO₂ NRs in the dark; however, they exhibited a prominent response for the PDT application under UV-A light. Therefore, it is concluded that TEMPO-coated TiO₂ NRs shows the synergistic response for therapeutic approach under UV-A light irradiation. In addition, TEMPO capped TiO2 nanorods not only overcome the multidrug resistance (MDR) hindrance but also exhibit excellent response for cancer cell (MCF-7 cells) treatment only under UV light irradiation via PDT. It is expected that the proposed TiO₂ NRs + TEMPO nanocomposite, which is suitable for PDT treatment, may be essential for photodynamic therapy.