NIR-Triggered Hyperthermal Effect of Polythiophene Nanoparticles Synthesized by Surfactant-Free Oxidative Polymerization Method on Colorectal Carcinoma Cells

In this work, polythiophene nanoparticles (PTh–NPs) were synthesized by a surfactant-free oxidative chemical polymerization method at 60 °C, using ammonium persulphate as an oxidant. Various physicochemical properties were studied in terms of field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infra-red (FT-IR) spectroscopy, and differential scanning calorimetry (DSC)/thermogravimetric analysis (TGA). Photothermal performance of the as-synthesized PTh–NPs was studied by irradiating near infra-red of 808 nm under different concentration of the substrate and power supply. The photothermal stability of PTh–NPs was also studied. Photothermal effects of the as-synthesized PTh–NPs on colorectal cancer cells (CT-26) were studied at 100 µg/mL concentration and 808 nm NIR irradiation of 2.0 W/cm(2) power. Our in vitro results showed remarkable NIR laser-triggered photothermal apoptotic cell death by PTh–NPs. Based on the experimental findings, it is revealed that PTh–NPs can act as a heat mediator and can be an alternative material for photothermal therapy in cancer treatment.