Aiding Tumor Visualization with Nanomaterials

Cancer diagnoses, and increasingly treatment, are progressively aided by the development of new medical and molecular imaging instrumentation. Central to the power of these procedures has been the concurrent development of contrast agents that allow clearly delineated tumor peripheries. Nanotechnology has provided innovative materials that have been proven to provide elevated contrast in a number of different imaging modalities; tumor tissue-specific nanoparticles for example have shown great potential as contrast agents for in vivo imaging of several cancer types.

This seminar will focus on two examples of nanoscale contrast agents. The first being a composite material consisting of Fe3O4 nanoparticles embedded in a 200 nm diameter porous Si (pSi) nanoparticle “superstructure” as a potential magnetic resonance imaging contrast agent. The composite material reported here exploits the dipolar coupling of superparamagnetic nanoparticles trapped within a secondary inorganic matrix to enhance the transverse relaxivity contrast in a 3 T MRI greater than 1.6 fold over similar Fe3O4 nanoparticles. The second topic will be the enhanced visualization of breast cancer in X-ray Computed Tomography that we achieved by using Bi2S3 nanoparticles of 10 nm diameter modified to display a tumor targeting peptide (LyP-1, CGNKRTRGC). In these studies the accumulation of the nanoparticle contrast agent within the tumor was increased by 260 % over nanoparticles that did not contain the homing peptide.