Synthetic Inorganic and Materials Chemistry
The Huang group research centers on the design and synthesis of novel inorganic and organic-inorganic hybrid materials including nanomaterials with potential for energy conversion and storage, environmental protection and remediation, and biomedical and healthcare applications. Recently, we have developed a new nanoplatform based on Prussian blue (PB) and its many analogs to deliver various main-group, transition and lanthanide metal ions into biological cells for both diagnostic and therapeutic applications.
Magnetic resonance imaging (MRI) has emerged as a prominent diagnostic modalities in modern medicine. To improve the quality of image, a contrast agent (CA), is often intravenously administered. Two types of MRI contrast agents are currently used in clinical diagnosis: T1-weighted and T2-weighted agents. Most clinical T1 agents consist of the Gd3+ ion chelated by a polyaminopolycarboxylate ligand, while all the T2 agents are prepared from superparamagnetic iron oxide nanoparticles (SPIOs). The commercial Gd3+-chelates have low sensitivity (relaxivity), and thus requiring a high tissue concentration to be effective for MR imaging. In addition, such small-molecule agents lack the ability to penetrate cells, making them unsuitable for cellular imaging and drug delivery applications. Conversely, the image contrast produced by a T2 agent is often interfered by signals caused by bleeding, calcification, metal deposits, or other background artifacts, making the interpretation of MR radiograms difficult. We have developed a new generation of T1 contrast agents based on PB and its transition and lanthanide analogs with high relaxivity, long blood circulation times, and ability to penetrate cells for clinical imaging and biomedical research. One of our nanoparticulate Mn(II) agents is currently under pre-clinical evaluation as a potential oral MRI contrast agent.
As the gold standard in diagnostic medicine, X-ray computed tomography (CT) often requires the use of a contrast agent as well. Unlike MRI contrast agents, effective CT contrast agents need to contain elements of high atomic numbers as they have the ability to increase the attenuation of X-rays. Currently, the clinical CT agents are exclusively iodinated organic compounds. However, the use of nanoparticle-based CT contrast agents is expected to have several advantages in terms of imaging characteristics. The heaviest stable, non-radioactive and nontoxic element with a strong X-ray attenuation power in the periodic table is bismuth (Z=83). We are systematically investigating the design, synthesis and X-ray attenuation properties of bismuth compounds as potential nanoparticulate CT contrast agents.
Our exploratory synthesis has also led to the discovery of a variety of novel materials ranging from organic-inorganic hybrid compounds with novel ferroelectric and multiferroic properties to microporous solids with selectivity for radioactive 137Cs and 90Sr ions, and to bismuth-based wide bandgap semiconductor nanoparticles with photocatalytic properties.
Scholarly, Creative & Professional Activities
- Perera, V. S., Hao, J., Gao, M., Gough, M., Zavalij, P. Y., Flask, C., Basilion, J. P. & Huang, S. D. Nanoparticles of the Novel Coordination Polymer KBi(H2O)2[Fe(CN)6].3H2O As a Potential Contrast Agent for Computed Tomography. Inorganic Chemistry 50, Article ASAP on July 28 (2011).
- Shokouhimehr, M., Soehnlen, E. S., Hao, J., Griswold, M., Flask, C., Fan,X., Basilion, J. P., Basu, S. & Huang S. D. Dual Purpose Prussian Blue Nanoparticles for Cellular Imaging and Drug Delivery: A New Generation of T1Weighted MRI Contrast and Small Molecule Delivery Agents Journal of Materials Chemistry 20, 5251-5259(2010).
- Shokouhimehr, M., Soehnlen, E. S., Khitrin, A., Basu, S. & Huang S. D. Biocompatible Prussian Blue Nanoparticles: Preparation, Stability, Cytotoxicity, and Potential Use as an MRI Contrast Agent Inorganic Chemistry Communications 13, 58-61(2010).
- Zhang, W., Ye, H.-Y., Ca, H.-L., Ge,J.-Z., Xiong, R. G. & Huang, S. D. Discovery of New Ferroelectrics: [H2dbco]2·[Cl3]·[CuCl3(H2O)2]·H2O (dbco=1,4-Diaza-bicyclo[2.2.2]octane) Journal of the American Chemical Society 132, 7300-7302(2010).
- Zhang, W., Chen, L. Z., Xiong, R. G., Nakamura, T. & Huang S. D. New Ferroelectrics Based on Divalent Metal Ion Alum Journal of the American Chemical Society 131, 12544-12545(2009).
- Ye, H., Fu, D., Zhang, Y., Zhang, W., Xiong, R. G. & Huang, S. D. Hydrogen-Bonded Ferroelectrics Based on Metal-Organic Coordination Journal of the American Chemical Society 131, 42-43(2009).
- Zhang, W., Xiong, R. G. & Huang S. D. 3D Framework Containing Cu4Br4 Cubane as Connecting Node with Strong Ferroelectricity Journal of the American Chemical Society 130, 10468-10469(2008).
- Zhang, W., Xiong, R.-G. & Huang, S. D. 3D Framework Containing Cu4Br4 Cubane as Connecting Node with Strong Ferroelectricity. Journal of the American Chemical Society 130, 10468-10469 (2008).
- Huang, T., Vanchura, B. A., Shan, Y. & Huang, S. D. Na(H3NCH2CH2NH3)0.5[Co(C2O4)(HPO4)]: A novel phosphoxalate open-framework compound incorporating both an alkali cation and an organic template in the structural tunnels. Journal of Solid State Chemistry 180, 2110-2115 (2007).
- Fu, D.-W., Song, Y.-M., Wang, G.-X., Ye, Q., Xiong, R.-G., Akutagawa, T., Nakamura, T., Chan, P. W. H. & Huang, S. D. Dielectric Anisotropy of a Homochiral Trinuclear Nickel(II) Complex. Journal of the American Chemical Society 129, 5346-5347 (2007).
- Ye, Q., Song, Y. M., Wang, G. X., Chen, K., Fu, D. W., Chan, P. W. H., Zhu, J. S., Huang, S. D. & Xiong, R. G. Ferroelectric metal-organic framework with a high dielectric constant. Journal of the American Chemical Society 128, 6554-6555 (2006).