Short-Pulse Laser-Based System for Detection of Tumors: Administration of Gold Nanoparticles Enhances Contrast

The objective of this paper is to demonstrate the use of gold nanoparticles, which accumulate in tumors due to the leakiness of tumor vasculature, as contrast agents for enhanced imaging in a time-resolved optical tomography system using short-pulse lasers for skin cancer detection. Mouse tissue was analyzed in vivo by optical coherence tomography during exposure to the beam of either a 514nm, 200ps pulsed laser or a 776nm, 1.3ps pulsed laser. It was found that addition of spherical gold nanoparticles, either by injection under the skin or by intravenous administration, decreased total reflection intensity and broadened the temporal profile of reflected photons. Together, these results show that gold nanoparticles tuned to the wavelength of the laser can enhance contrast between labeled and unlabeled tissues, and suggest that gold nanoparticles may enhance the sensitivity and resolution of laser-based cancer detection and therapeutic treatment.