Synthesis of Ultra-fine Metal Particles

Ultra-fine metal particles with diameters in the nanometer size range often exhibit unique size-dependent electronic and physical properties. Nanostructured materials produced by consolidation of nanoscale metal particles or by dispersing nanoscale metal particles on or in various solid supports also exhibit unique properties. The key to taking advantage of these enhanced properties are techniques for synthesizing the ultra-fine metal particles of interest at high production rates and low cost. We have developed several aerosol based methods for nanoparticle synthesis and are involved in extending our understanding of these processes by theoretical modeling and experimental scale up.

Self-Assembly of 2-D and 3-D Nanoparticle Structures

Many of the most exciting materials applications of ultra-small particles require that these particles be assembled into regular 2-D or 3-D superlattices. The only feasible way to accomplish this task appears to be via self-assembly, which can be defined as a process in which a supramolecular hierarchical organization is spontaneously established in a complex system of interlocking components. We have developed methods for the engineered self-assembly of nanoparticle superlattices and are involved in improving these techniques and extending our understanding of the basic physics of the self-assembly process.

Targeting Cancer Cells with Functionalized Nanoparticles

Current anti-cancer agents suffer from several limitations: they are typically highly toxic, they often are non-specific in that they target both normal as well as cancerous cells, they have poor bioavailability, and they exhibit short half lives and fast clearance from the body. An ideal therapeutic solution to these problems would be to deliver a high concentration of the anti-cancer agent or multiple agents by attaching them to the surface of a nanoparticle that is small enough to be transported through the circulatory system, is not rapidly cleared from the body, and is selectively targeted to cancerous cells. We have developed methods to synthesize metal nanoparticles that are water soluble over a wide range of pH and electrolyte concentration, are not removed from the body by the immune system due to recognition by macrophages, and are selectively targeted to cancer cells.

V. Santhanam, J. Liu, R. Agarwal, R.P. Andres, "Self-assembly of uniform monolayers of nanoparticles," Langmuir, 19, 7881 (2003).

V. Santhanam and R.P. Andres, "Microcontact printing of uniform nanoparticle arrays," Nano Lett., 4, 41 (2004).

V. Dixit, J. Van den Bossche, D.M. Sherman, D.H. Thompson, R.P. Andres, "Synthesis and grafting of thioctic acid-PEG-folate conjugates onto Au nanoparticles for selective targeting of folate receptor positive tumor cells," Bioconjugate Chem., 17,603 (2006).

R.P. Andres and A.T. Ng, U.S. Patent 7,186,398 B2 (3-6-07), "Fe/Au Nanoparticles and Methods".