Tumor treatment with targeted nanoworms. Mice bearing orthotopic xenografts of 22Rv1 or LAPC9 human prostate cancer (2 weeks or 10 days after inoculation, respectively) were injected intravenously with nanoworms coated with peptides through a 5-kDa PEG spacer. The particles were administered every other day for 14 days (5 mg of iron per kilogram per day, total cumulative dose 35 mg/kg). (A) Tumor volume 1 day after the last injection in the 22Rv1 model is shown. Statistical analyses were performed with analysis of variance. Error bars show SEM (n = 10-12); **P < .01; ***P < .001. Similar results were obtained in 2 independent experiments. (B) Mice bearing LAPC9 tumors were treated as described in panel A, and survival was monitored over time (n = 8 per group). The arrow indicates the day the nanoworm treatment was stopped.