Combination of transfection agents and magnetic resonance contrast agents for cellular imaging: Relationship between relaxivities, electrostatic forces, and chemical composition
✍ Scribed by H. Kalish; A.S. Arbab; B.R. Miller; B.K. Lewis; H.A. Zywicke; J.W.M. Bulte; L.H. Bryant Jr.; J.A. Frank
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 576 KB
- Volume
- 50
- Category
- Article
- ISSN
- 0740-3194
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✦ Synopsis
Abstract
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/T~1~, 1/T~2~), MRI and zeta potential (ZP) of CA‐TA solutions were measured. TAs decreased the 1/T~1~ and 1/T~2~ of G5‐DOTA‐Gd, Feridex®, and MION‐46L by 0–95%. Altering the pH of G5‐DOTA‐Gd‐TA decreased the T~1~‐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. Magn Reson Med 50:275–282, 2003. Published 2003 Wiley‐Liss, Inc.