Harnessing nanoparticles to improve toxicity after head and neck radiation.

This article reports the evaluation of cerium oxide (CeO(2)) nanoparticles' ability to decrease xerostomia and radiation-induced dermatitis in mice after head and neck radiation. Mice were irradiated using an IC160 x-ray system. Two cohorts were included: (A) No-radiation and (B) 30 Gy/6 fractions, and were randomized into three groups: (1) saline, (2) 15 nM CeO(2) and (3) 15 µM CeO(2). Stimulated salivary flow and radiation-induced dermatitis were evaluated post radiation. Stimulated sialometry demonstrated improved salivary production in all CeO(2) groups in comparison with controls (flow: 204 vs. 115 µL/10 minutes, P = 0.0002). One week post radiation, G-III dermatitis decreased in the 15 µM group in comparison with controls (10% versus 100% incidence, respectively). There was decreased skin hyperpigmentation at 12 weeks in the 15-µM group in comparison with 15-nM and non-CeO(2) groups (50%, 70%, and 90% G-II, respectively). This study suggests that CeO(2) may be radioprotective for salivary production and reduces G-III dermatitis and skin hyperpigmentation incidence. CeO(2) as radioprotectant may be a feasible concept during radiotherapy. FROM THE CLINICAL EDITOR: This study demonstrates in a mouse model that cerium oxide (CeO(2)) nanoparticles may provide an important mechanism in preventing radiation induced xerostomia, a common complication of head and neck radiation treatments.

Bioluminescence imaging correlates with tumor progression in an orthotopic mouse model of lung cancer.

BACKGROUND AND OBJECTIVES: To determine whether bioluminescence imaging of human lung cancer cells growing in an orthotopic murine model provides a sensitive tool for monitoring tumor progression in athymic nude mice. METHODS: Human lung cancer (A549) cells were stably transfected with the firefly luciferase gene and inoculated into the right lung of athymic nude mice. Seven days after inoculation tumor growth was evaluated using the Kodak in-vivo Imaging System FX and continued to be monitored on a weekly basis. RESULTS: In duplicate experiments, human lung cancer tumors formed in 90% of animal's injected orthotopically. The mean intensity of the bioluminescence signal emitted from the lung cancer cells increased logarithmically during the course of study. Mice with positive bioluminescence signaling had confirmed tumors by microscopic histological analysis. Bioluminescence activity had a strong correlation with the tumor volume as determined histologically. CONCLUSIONS: Bioluminescence intensity directly correlates with tumor volume and therefore offers a reliable approach for detecting and monitoring the growth of human lung cancer cells in orthotopic murine models.