Diagnostic and therapeutic applications of metal nanoshells
Hirsch, Leon Robert
West, Jennifer L.
Doctor of Philosophy
Metal nanoshells are a new class of optically tunable core/shell nanoparticles which are finding numerous applications in biomedicine due to their biocompatibility, chemical functionability, and optical tunability in the near infrared (a region of light where tissue is optically transmissive). The following work explores the design of near infrared resonant nanoshells for two new diagnostic and therapeutic biomedical applications. For diagnostic purposes, near infrared resonant nanoshells were found to be optically detectable in whole blood and proved capable of detecting sub-nanogram levels of analyte in whole blood in under 30 minutes. For therapeutic purposes, near infrared absorbing nanoshells were heated in tumors using higher laser powers. Excitation of near infrared resonant nanoshells promoted photothermal destruction of cancerous growths in vitro as well as in vivo. In vitro, nanoshell treated cells were photothermally ablated upon near infrared excitation with no detectable damage to cells receiving lasers only. Similar results were found in whole tissue. Using a live mouse model, a complete therapy system was demonstrated where systemically delivered nanoshells were found to preferentially accumulate into tumors. Near infrared excitation of these tumors provided complete recovery in 55% of the cases, while controls displayed a mean survival time of only 15--20 days.
Biomedical engineering; Oncology