Figure 4. Intraperitoneal photothermal therapy induced by pSGNs with NIR laser irradiation.
A. Three hundred thousand ID8 cells, B. one million TOV21G cells and C. 1 × 106 SKOV-3 cells were intraperitoneally injected into NOD/SCID mice. After 2 days for ID8 cells and after 6 days for TOV21G and SKOV-3 cells, the mice were intraperitoneally injected with 2 mL of pSGNs (OD800 = 1.5) and irradiated using an 808-nm NIR laser (3.2 W/cm2) in five areas on the abdomen for a total of 5 min. The NIR laser irradiation was repeated every 3 to 4 days, and the pSGNs were supplemented on the third and eighth days. Tumor sizes were represented by the chemoluminescent intensity and determined using an IVIS spectrum system. In these tumor cell models, the tumor growth was slightly inhibited through the NIR laser irradiation or the pSGNs treatment. However, intraperitoneally administered pSGNs combined with NIR laser irradiation significantly inhibited tumor growth compared with the control, NIR-only, and pSGNs-only groups in both tumor cell models. These results demonstrated that repeated photothermal therapy can inhibit i.p. tumor growth in vivo. The error bars in each chart represent the standard error. (P < 0.05#, <0.01*, <0.001**, <0.0001***)