Fig. 4

In vitro synergistic photonic hyperthermia and chemotherapy. A Schematic illustration of HPDC NPs for synergistic hyperthermia and chemotherapy against walker256 tumor cells. B Relative cell viability of walker256 cells co-incubated with HPDC NPs at varied concentrations for different treatment durations. C Relative cell viability after varied treatments, including control, NIR − I laser only, HPDC NPs only, DOC only, HPC NPs + NIR − I laser, and HPDC NPs + NIR − I laser groups. All data are presented as mean ± standard and Student’s two-tailed t test (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001), n = 3 per group. (D–F) Relative cell viability of HPDC NPs at different concentrations (0, 50, 100, 200, and 400 ppm) under 808 nm laser irradiation at the power intensity of 0.5, 1, and 1.5 W cm⁻² for 2 and 5 min. G Observed CLSM images of walker256 cells stained by PI and calcein-AM (Scale bar was 100 μm). H Flow cytometry apoptosis assay of cancer cells stained by Annexin-FITC and PI after varied treatments: control, laser only, HPDC NPs only (200 ppm), DOC only (35 ppm), HPC NPs (200 ppm) + NIR − I laser, and HPDC NPs (200 ppm) + NIR − I laser groups. The power density was 1.0 W cm⁻² and the irradiation time was 5 min