^99mTc /SPIO-loaded polymeric micelles as MRI and SPECT imaging, cancer-targeted nanoprobe for liver cancer detection

Abstract

Magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) imaging are combined to diagnose cancer with high physiological, anatomical, and metabolism sensitivity. For targeting hepatoma carcinoma, a drug delivery system is employed to carry drugs or chemicals to a specific area. Galactose is one of the sugar molecules which can be bound and increase uptake with asialoglycoprotein receptor (ASGP-R). In this study, superparamagnetic iron oxide nanoparticles (SPIONs), Galactose-functionalized poly(ethylene glycol)-block-poly(lactic acid) (Gal-PEG-b-PLA) and Diethylenetriaminepentaacetic acid-functionalized poly(ethylene glycol)-block-poly(lactic acid) (DTPA-PEG-b-PLA) were successfully synthesized and constructed to DTPA/Gal/SPIO micelles (targeting micelles) and DTPA/Met/SPIO micelles (non-targeting micelles). Technetium-99 m (99mTc) formed a complex with DTPA on the micelles as 99mTc/Gal/SPIO micelles by using stannous chloride and the pH was adjusted to acidic condition. The sizes of DTPA/Gal/SPIO micelles and DTPA/Met/SPIO micelles were lower than 100 nm with a spherical shape. In vitro study with HepG2-and L929-incubated micelles showed the intensity of blue staining of Prussian blue related to the amount of SPIO. 99mTc/Gal/SPIO micelles incubated with HepG2 exhibited signal intensity (SPECT signal) and relative R2* (MRI signal) higher than 99mTc/Met/SPIO micelles at the same time. According to these results, 99mTc-labeled Galactose-functionalized SPIO micelles have the potential for specific targeting to HepG2 and can aid in the diagnosis of cancer with MRI and SPECT dual imaging.