NIR-PIT for Lung Tumor Regression in Mice

Lung tumor bearing transgenic mice were randomized into 3 groups at least 5 animals for the following treatments: (1 (link)) no treatment (control); (2 (link)) 150 μg of pan-IR700 i.v. but no NIR light exposure (APC i.v. only); (3 (link))150 μg of pan-IR700 i.v. followed by NIR light at 50 J/cm² on day 1 after intravenous injection of pan-IR700 (NIR-PIT). The mice were irradiated with NIR light from 2 directions (each 25 J/cm²) via the back and front using NIR laser light at 685 to 693 nm wavelength (BWF5-690-8-600-0.37; B&W TEK INC., Newark, DE, USA) (500 mW/cm² × 50 s, 25 J/cm²) while the remainder of the body was shielded from light with aluminum foil. The power density of light in mW/cm² was measured with an optical power meter (PM100, Thorlabs, Newton, NJ, USA). These therapies were performed every week for up to 3 weeks. Fluorescence images were not obtained because IR700 fluorescence accumulated within lung tumors was not detectable outside the body.