The purpose of this study was to investigate the changes in electrostatic and magnetic resonance (MR) properties observed when MR contrast agents (CAs) (Feridex®, MION-46L, or G5-dendrimer-DOTA-Gd) are combined with transfection agents (TAs) under various conditions for use as a CA-TA complex basis for cellular labeling and MRI. CAs were incubated with various classes of TAs for 0-48 hr in solutions of varying concentrations and pH values. NMR relaxation rates (1/T1, 1/T2), MRI and zeta potential (ZP) of CA-TA solutions were measured. TAs decreased the 1/T1 and 1/T2 of G5-DOTA-Gd, Feridex®, and MION-46L by 0-95%. Altering the pH of G5-DOTA-Gd-TA decreased the T1-weighted signal intensity (SI) on MRI from 0 to 78%. Measured ZP values for G5-DOTA-Gd, Feridex®, and MION-46L were -51, -41, and -2.0 mV, respectively. The TA LV had a negative ZP, while the other TAs had ZPs ranging from +20 to +65 mV. The alteration of the ZP and NMR relaxivities of the MR CAs, Feridex®, MION-46L, and G5-DOTA-Gd by TAs has been demonstrated. These results enhance our understanding of the relationship between electrostatic and MR properties.
- Contrast agent
- Transfection agents
- Zeta potential
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging