Preliminary study on 64Cu labeled single-stranded DNA and its distribution in vivo

Abstract

BackgroundDNA (DeoxyriboNucleic Acid) polyhedral structure has great potential in molecular imaging probe with good properties in model animals such as low toxicity, low immunogenicity and excellent in vivo stability.PurposeThis article aims to use positron emission computed tomography (PET) radionuclide 64Cu to label DNA single strands instead of SPECT radionuclide 99mTc, and to study the distribution and metabolism of 64Cu labeled DNA single strands in Kunming mice in vivo.MethodsSingle strand DNA (ssDNA) was coupled with chelating agent p-SCN-Bn-NOTA and incubated with 64Cu for a certain time to obtain NOTA-ssDNA. The labeling reaction was monitored by thin layer chromatography, and purified by NAP-5 desalting column to obtain 64Cu-ssDNA. After injection into Kunming mice, the radioactive uptakes of organs of interest at different time were studied.ResultsAfter NOTA-ssDNA reacted with 64Cu for 1 h, the radiochemical labeling rate is (66.4±2.85)%. After purification, the radiochemical purity is >95%. The in vitro stability experiments show that 64Cu-ssDNA can stably exist in PBS and mouse serum for at least 6 h. There was a certain uptake in the gastrointestinal tract and high radioactive uptake in both the kidney and bladder after 64Cu-ssDNA is injected into the mice, indicating that 64Cu-ssDNA is mainly excreted through the urinary system.ConclusionsSuccessful preparation of 64Cu-ssDNA is a critical step for the preparation of PET molecular probes based on DNA polyhedral. In vivo distribution experiment provides experimental control data for studying the in vivo biological distribution of 64Cu labeled DNA polyhedra.

Keywords

• single-stranded dna
• copper-64 labeling
• in vivo distribution