Advanced Powder Technol., Vol. 18, No. 6, pp. 663–698 (2007)  VSP and Society of Powder Technology, Japan 2007. Also available online - www.brill.nl/apt Invited paper Gd nanoparticulates: from magnetic resonance imaging to neutron capture therapy PARVESH SHARMA 1,2 , SCOTT C. BROWN 1 , GLENN WALTER 3 , SWADESHMUKUL SANTRA 4 , EDWARD SCOTT 5 , HIDEKI ICHIKAWA 6 , YOSHINOBU FUKUMORI 6 and BRIJ M. MOUDGIL 1,∗ 1 Department of Materials Science & Engineering and Particle Engineering Research Center, PO Box 116135, University of Florida, Gainesville, FL 32611, USA 2 Department of Chemistry, St Stephen’s College, Delhi University, Delhi 110007, India 3 Department of Physiology and Functional Genomics, McKnight Brain Institute, University of Florida, Gainesville, FL 32611, USA 4 NanoScience Technology Center, Department of Chemistry and Burnett College of Biomedical Sciences, University of Central Florida, Orlando, FL 32826, USA 5 Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32611, USA 6 Pharmaceutical Sciences and Cooperative Research Center of Life Sciences, Kobe Gakuin University, Arise 518, Ikawadani-cho, Nishi-ku, Kobe 651-2180, Japan Received 15 May 2007; accepted 25 July 2007 Abstract—Gadolinium (Gd) chelates have been extensively applied to enhance the imagery of anatomical tissues via magnetic resonance imaging (MRI). These molecular complexes have become some of the most common clinically applied contrast agents in modern medicine. The expansive development and clinical application of Gd chelates for MRI applications has led to a rebirth of interest in the use of Gd as a radiosensitizer in neutron capture therapy (NCT). However, the poor selective tissue labeling and localization provided by conventional molecular Gd chelates has limited success in both MRI and NCT applications. Methods for encapsulating Gd into nanoparticulate materials have been developed to overcome these limitations. Incorporating Gd chelates into nanoparticulate materials affords additional flexibility in engineering targeting and also provides a means to apply high tissue-centric concentrations of Gd — often critical for both imaging and therapeutic applications. The focus of this review is to summarize the evolution of engineered Gd nanoparticles, from self- assembled macromolecular structures to rigid particulate systems for enhanced MRI contrast and, separately, Gd NCT therapy. Keywords: Gadolinium; nanoparticles; magnetic resonance imaging; neutron capture therapy; cancer; liposomes; emulsions; dendrimer. ∗ To whom correspondence should be addressed. E-mail: bmoudgil@erc.ufl.edu