Fig. 5. (a) Fluorescence images of HeLa cells treated with DMEM, ICG@PSMA NPs, laser only and ICG@PSMA NPs and laser (808 nm laser irradiation at a power density of 900 mW cm⁻² for 10 minutes) after stained by annexin V-FITC. Scale bar: 50 μm. λ_ex = 640 nm (ICG); λ_ex = 530 nm (FITC). Images were obtained at a 10 × objective. (b) Flow cytometric analysis by annexin V-FITC and PI staining: (1) control, (2) laser only, (3) ICG@PSMA NPs (50 μg mL⁻¹), (4) ICG@PSMA NPs (50 μg mL⁻¹) and Laser (808 nm laser irradiation at a power density of 900 mW cm⁻² for 8 minutes).