Fig. 3.

(a) Cellular uptake and localization of fluorescein isothiocyanate (FITC)-labeled TCPR NPs (green fluorescence) at a concentration of 100 µg mL⁻¹ at different time points. The cell nuclei were stained with 4′, 6-diamidino-2-phenylindole (DAPI). (b) Cell viability of human-immortalized keratinocytes (HaCaTs) incubated with TCPR NPs at various concentrations. (c) Viability of 4T1 cells cultured with NPs of TPR or TCPR at different concentrations with and without laser irradiation (10 min, 1 W cm⁻², 1060 nm). (d) Reactive oxygen species (ROS) staining for intracellular radical detection (incubated with NPs [50 µg mL⁻¹] for 8 h). (e) Live/dead staining of 4T1 cells after treatment (50 µg mL⁻¹) under laser irradiation (10 min, 1 W cm⁻², 1060 nm). (f) Annexin-V-FITC/propidium iodide (PI) flow cytometry assay. (g) Western blotting assay of caspase-3, B-cell lymphoma (Bcl)-2, and Bcl-2-associated X (Bax) protein expression. (h) Schematic illustration of cell apoptosis caused by TCPR NP-induced hypothermia (***p < 0.001).