Work

Silica Microparticles as a Solid Support for Gadolinium Phosphonate Magnetic Resonance Imaging Contrast Agents

Year: 2012

Type: article

Abstract: Particle-based magnetic resonance imaging (MRI) contrast agents have been the focus of recent studies, primarily due to the possibility of preparing multimodal particles capable of simultaneously targeting, imaging, and treating specific biological tissues in vivo. In addition, particle-based MRI contrast agents often have greater sensitivity than commercially available, soluble agents due to decreased molecular tumbling rates following surface immobilization, leading to increased relaxivities. Mesoporous silica particles are particularly attractive substrates due to their large internal surface areas. In this study, we immobilized a unique phosphonate-containing ligand onto mesoporous silica particles with a range of pore diameters, pore volumes, and surface areas, and Gd(III) ions were then chelated to the particles. Per-Gd(III) ionic relaxivities ranged from ∼2 to 10 mM(-1) s(-1) (37 °C, 60 MHz), compared to 3.0-3.5 mM(-1) s(-1) for commercial agents. The large surface areas allowed many Gd(III) ions to be chelated, leading to per-particle relaxivities of 3.3 × 10(7) mM(-1) s(-1), which is the largest value measured for a biologically suitable particle.

Source: Journal of the American Chemical Society

DOI: 10.1021/ja302183w

Authors: Alexandra K. Duncan, Piper J. Klemm, Kenneth N. Raymond, Christopher C. Landry

Institutions: University of Vermont, University of California, Berkeley

Language: English

Topic: Lanthanide and Transition Metal Complexes

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: National Heart, Lung, and Blood Institute, National Cancer Institute, National Institute of Environmental Health Sciences

Awards: Hydroxypyridonate Gd Complexes: MRI Agents, G155051027, G2908379384, G5879515667, Improving the Transfer of ERK siRNA Constructs Using Nanoporous Silica