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

Abstract

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.