Figure 3. Effect of CpG-PBNP-PTT on tumor regression and long-term survival in a primary, 9464D model of NB.

(A) Schematic of the treatments. (Left) Mice bearing ~5 mm diameter 9464D tumors were treated with vehicle (PBS), PBNP-PTT or CpG-PBNP-PTT,. (Right) The vehicle group received 50 μL of PBS intratumorally (i.t.), The PTT-treated groups received 50 μL of 1 mg mL⁻¹ PBNPs or CpG-PBNPs i.t., and were irradiated with an 808 nm laser for 10 minutes at a temperature maintained at 120 °C. Additionally, the CpG-PBNP-PTT group received two boosters with CpG-PBNPs on days 2 and 5. The dosage of CpG for this group was 2 μg of CpG conjugated onto PBNP on days 0, 2, and 5 i.t.. (B–C) Temperature versus time profiles (B) and thermal doses administered expressed in cumulative equivalent minutes at 43 °C (log(∑CEM43)) (C) of 9464D tumor-bearing mice treated i.t. with 50 μL of 1 mg mL⁻¹ CpG-PBNPs or PBNPs and irradiated with a NIR laser at 120°C for 10 minutes. (D) Kaplan–Meier survival plots of 9464D tumor-bearing mice that were treated with CpG-PBNP-PTT, PBNP-PTT, or vehicle (PBS) on Day 18 and rechallenged on Day 80. (E–G) Individual tumor growth curves of 9464D tumor-bearing mice receiving vehicle (PBS) (E), PBNP-PTT (F), or CpG-PBNP-PTT (G). Results are expressed as mean ± std. deviation; (n=5); *p < 0.05, **p < 0.01 (ANOVA).