Radiation-Luminescence-Excited Quantum Dots for in vivo Multiplexed Optical Imaging

Materials: Na131I was purchased from Perkin Elmer (Waltham, MA). QDs were obtained from Invitrogen Life Technologies (Carlsbad, CA). Female athymic nude mice (nu/nu), obtained from Charles River Laboratories, Inc. (Cambridge, MA), were 4-6 weeks of age. A CRC-15R PET dose calibrator (Capintec Inc., Ramsey, NJ) was used for all radioactivity measurements. Radioactive optical imaging: In vivo radioactive optical imaging was performed with IVIS 200 and Spectrum systems. Wavelength-resolved spectral imaging was carried out using an 18-set narrow-band emission filter set (490-850 nm). Animals were placed in a light-tight chamber under isofluorane anesthesia. Each acquisition, with or without filters, took 1-3 min for all studies. Images were acquired and analyzed using Living Image 3.0 software (Caliper life sciences, Hopkinton, MA). The optical signal was normalized to photons per second per centimeter square per steradian (p/s/cm2/sr). Identical settings were used for in vitro Radioactive OI. For in vivo imaging studies, 0.37 MBq (10 μCi) Na 131I with or without QDs were dissolved in 25 μL of PBS, and then mixed with an equal volume of Matrigel (BD Biosciences, Bedford, MA) at 4 °C. A total volume of 50 μL of Matrigel mixture was injected into normal mice (n=3) subcutaneously or intramuscularly. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.