Fig. 6.

Targeted photothermal therapy in preclinical models of breast and prostate cancer. (A) Targeted hydrogels were injected in vivo and the NIR laser was illuminated after 24 h with the power density set at 3.5 W/cm² (*P < 0.05). Box-and-whiskers plots, median line; box, quartiles; whiskers, 5–95% confidence. (B) Targeted dox-HSL–containing hydrogels (Upper) or dox-HSL alone (Lower) were administered to mouse cohorts, and the temperature changes during NIR laser illumination at 3.5W/cm² were monitored. (C) The NIR laser illuminated tumors while MRTI was performed. The largest temperature change during NIR laser illumination was mapped (Inset). The time course of temperature changes in the ROI in tumor and nonmalignant tissue. Tumor region (●); nontumor region (○). (D) T1 mapping of a tumor section before (○) and after (■) the NIR laser treatment. (E) The tumor treatment effect of targeted dox-HSL–containing hydrogel (●) photothermal therapy was evaluated relative to dox-HSL (○) or PBS (♦) treatment. Black arrow, hydrogel administration; red arrow; NIR laser treatment at 3.5 W/cm² for 3 min (shown data are mean ± SEM; **P < 0.01, ***P < 0.001; n = 7). (F) Logplot of viability data M/M₀ for targeted hydrogel delivery (■) as a fraction of PBS controls vs. time (P = 0.00019, R² = 0.98). For comparison, the dox-HSL (□) results are also shown (P = 0.0018, R² = 0.98). (G and H) Delivery of targeted (■) and control (□) FITC-MSNP–containing hydrogel to EF43.fgf-4 tumor-bearing mice (G) and DU145 tumor-bearing mice (H) (shown data are mean ± SEM; n = 8). (I) Targeted dox-MSNP–containing hydrogels in EF43.fgf-4 tumor-bearing mice gives a tumor growth delay (*P < 0.05; n = 8).