Cell biophysical characteristics of PPy-GNPs and their application in photothermal therapy of SKOV-3 cell

The pursuit of multifunctional, stable, more efficient, and safer cancer treatment has gained increasing interest in the research of nanoparticle-mediated photothermal therapy. Many nanoparticles have good absorption chracteristics in the near-infrared region, because of the high light-to-heat conversion efficiency; they could destroy tumor cells by heat; thus, they are often treated as a potential photothermal therapy agent. In this work, a kind of polypyrrole (PPy)-coated gold nanoparticles particles (PPy-GNPs) with high photothermal conversion capability was prepared. Their particle sizes were about 90 ± 11.2 nm. The temperature of PPy-GNPs solution in a concentration of 0.25 mg/ml rises 13.6 °C, and the nanoparticles could significantly inhibit the proliferation of SKOV-3 cells under irradiation of 25 W·cm−2 laser (808 nm) for 10 min, with the maximum cell viability value is maintained at 87.6% by MTT assay. In the same photothermal and cultured conditions, the photothermal conversion efficiency and cytostatic effect of the gold nanoparticle are much lower than that of the PPy-GNPs group. The atomic force microscopy (AFM) was used to identify the function of nanoparticles for the structural changes of the cells. The SKOV-3 cell of adhesion forces decrease by 21%, and Young’s modulus increases by 26% compared with control. These results suggest that PPy-GNPs are effective targeted photothermal therapeutic agents for cancer treatment.