Posted: July 10, 2006

Metal-organic hybrids yield versatile nanoparticle-based imaging agents

(Nanowerk News) By combining the properties of inorganic and organic molecules in one material, researchers at the Carolina Center of Cancer Nanotechnology Excellence (CCNE) have developed a new class of nanomaterials that can be used to create multifunctional nanoparticles. In a first demonstration of the versatility of these new materials, the investigators created nanoparticles that enhance image quality in both fluorescence microscopy and magnetic resonance (MR) imaging.
A research team at the University of North Carolina at Chapel Hill headed by Wenbin Lin, a member of the Carolina CCNE, developed a general chemical method to synthesize the new nanoscale materials, which are comprised of metal atoms attached to a framework of organic molecules. As an example, the investigators created nanorods containing gadolinium, an element that produces a strong MR signal boost, connected into an organic molecular framework. The researchers published their work in the Journal of the American Chemical Society ("Nanoscale Metal-Organic Frameworks as Potential Multimodal Contrast Enhancing Agents").
When the researchers added europium or terbium, elements in the rare earth family that are naturally luminescent, to the reaction mixture the resulting nanorods were visible via both MR and fluorescence imaging. The degree of MR signal enhancement was at least 10-fold greater than that produced by gadolinium-based imaging agents now used in human clinical imaging applications.
The researchers have already determined which reaction conditions are critical to controlling the size of the resulting nanorods, which should enable them to create nanomaterials with a wide range of pharmacokinetic properties. The investigators also note that the organic framework of these new nanomaterials provides a ready attachment point for tumor targeting agents and anticancer drugs.
Source: National Cancer Institute