Crc 15 pet

Unless otherwise stated, chemicals were purchased from commercial sources and used without further purification. BD1047 for mice studies was purchased from Sigma Aldrich. [¹⁹F]FTC-146 (99.1 % chemical purity) reference compound was provided by Albany Molecular Research Inc. (Albany, NY). Radiochemistry and semi-preparative high performance liquid chromatography (HPLC) was performed using a TRACERlab FX-FN module (GE Healthcare) with an ancillary HPLC pump (Dionex P680) and UV detector (KNAUER K-2001). Analytical HPLC was performed on a quaternary pump (Agilent 1200 series) equipped with an autosampler, a photodiode array UV detector, and a model 105S single-channel radiation detector (Carroll & Ramsey Associates). Radiotracer doses for animal studies were measured using a dose calibrator (Capintec, CRC-15 PET). Positron emission tomography/computed tomography (PET/CT) imaging of mice was performed using microPET/CT hybrid scanner (Siemens Inveon). All PET data were reconstructed using a 3-dimensional ordered subsets expectation maximization algorithm (16 subsets, 4 iterations) with scatter and dead time correction, and a matrix size of 128 × 128 × 159. Attenuation correction was applied to dataset from CT image.

Fe₃O₄@Al(OH)₃ NPs containing 4.3 µg of iron were labeled with 10 MBq [¹⁸F]NaF, while 10⁶ mMSC plated the day before where labeled with NPs containing 21.4 µg of iron in 1 mL of saline (end concentration of iron on cells = 0.38 mM) and radiolabeled with 30 MBq [¹⁸F]NaF. For imaging purposes, serial dilutions of these NPs and cells were resuspended in equal amounts of saline and 2% agar (microbiology grade; Sigma-Aldrich; diluted in distilled water) in 200 µL Eppendorf tubes. The following controls were used: (1) equal amounts of saline and 2% agar, and (2) 5 × 10⁴ unlabeled mMSCs in saline and agar. The radioactivity present in the samples was measured using a dose calibrator (CRC-15 PET, Capintec Inc., Ramsey, NJ, USA). The tubes were then placed into a cylindrical in-house made Teflon holder (outer diameter = 7 cm, inner diameter = 3.5 cm) filled with 2% liquid agar. For more details on this phantom, see Trekker et al. [35 ]. After agar solidification, the phantom was scanned using PET/MRI. Three MRI measurements were performed per phantom.