Nanoshells are concentric nanoparticles consisting of two components: a dielectric core and a metallic shell.  These particles can be designed to have unique optical properties by altering the geometry.  Due to the "shell" structure of these nanoparticles, the optical properties of the particle are extremely sensitive to core/outer shell ratio.  Thus, the geometry and material properties of nanoshells can be designed such that they are useful for biological applications[1].  Specifically, the nanoshells can be tuned to possess certain optical properties as shown below.  Each of these vials of nanoparticles have been tuned to have different absorption spectra over the visible range.

An example of the optical tunability of nanoshells

 source: http://www.nanospectra.com/physics/physics.asp

One of the most important design considerations for nanoshells in biomedical applications is biocompatibility.  Consequently, nanoshells have been designed to consist of a silica core with a gold coating.  Both materials have proven to be biocompatible yet able to withstand the body's natural defense system.  Thus, these particles have garnered interest as tools for targeted optical tumor imaging/treatment, controlled drug delivery, and specific immunoassays[1].

The purpose of this website is to introduce to BME 240 (a graduate class of biomedical engineers at UCI) the potential of these nanoshells as a method to enhance selective photothermolysis as a means for tumor ablation.  The basic concept suggests that these particles could be tuned and used to enhanced contrast and allow for selective laser removal of tumors.