Remote loading of liposomes with a ¹²⁴I-radioiodinated compound and their in vivo evaluation by PET/CT in a murine tumor model.

ABSTRACT: Long circulating liposomes entrapping iodinated and radioiodinated compounds offer a highly versatile theranostic platform. Here we report a new methodology for efficient and high-yield loading of such compounds into liposomes, enabling CT/SPECT/PET imaging and ¹³¹I-radiotherapy. Methods: The CT contrast agent diatrizoate was synthetically functionalized with a primary amine, which enabled its remote loading into PEGylated liposomes by either an ammonium sulfate- or a citrate-based pH transmembrane gradient. Further, the amino-diatrizoate was radiolabeled with either ¹²⁴I (t_1/2 = 4.18 days) for PET or ¹²⁵I (t_1/2 = 59.5 days) for SPECT, through an aromatic Finkelstein reaction. Results: Quantitative loading efficiencies (>

SUBMITTER: Engudar G 

PROVIDER: S-EPMC6299439 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature