Event Information

Stephen P. O'Brien (Columbia University, Dept. of Applied Physics & Applied Mathematics)
Nanocrystals. Synthesis, Superlattices and Biomedical Applications
Abstract:

Nanocrystals prepared by modern materials chemistry methods are an incredibly versatile system and span many different types of materials. I outline two areas of research in my group that seek to take advantage of nanoparticle synthesis and properties for a “higher” purpose: self assembly into thin film superlattices and MR contrast agents. Monodisperse ligand coated crystalline nanoparticles can be used as building blocks to form simple ordered arrays, called superlattices, which resemble the close-packed structures of atoms in crystals or hard spheres. Retention of the original properties of the nanoparticles, such as the quantum size effect or superparamagetism is possible. The preparation of superlattices can be described as a co-crystallization of nanocrystal dispersions following appropriate choice of solvents, substrates and conditions for self-assembly. The superlattices that result exhibit remarkable structural and compositional diversity, representing a variety of close packed structures reminiscent of binary alloy phases, and spanning a combination of magnetic oxides, semiconductors and metals. The interface between magnetic resonance imaging (MRI) and nanotechnology invites new approaches to the diagnosis and treatment of disease, presenting unique challenges in contrast agent creation, such as the development of MR active compounds with target-specific characteristics. The magnetic properties of iron oxide nanoparticles are ideally suited to such a task. The challenge in using iron oxide nanoparticles as targeted MRI contrast agents has been in creating a surface structure that provides sufficient stability under biological conditions, resists non-specific adsorption, and is easily altered to target a wide range of antigens. Here we present the synthesis and demonstrate the utilization of a novel class of contrast agents: immunotargeted superparamagnetic iron oxide nanoparticles.

Host: Jie Liu

Friday, May 4, 2007, 3:30pm
Departmental Seminar