Final Report Summary - MINT (Multiphoton Ionization Nano-Therapy) The research entitled Multiphoton Ionization Nano-Therapy (MINT) involved the study of novel approaches for targeting cancer cells and small tumors using a combination of nanotechnology, high-power laser pulses, and advanced high-resolution optical imaging. After initial theoretical and experimental study of the fundamentals of laser-nanoparticles interactions, we have developed novel techniques for manipulating cancer cells by fusing neighboring cells, inducing programmed cell death, damaging cell membrane structure and integrity, and releasing anticancer drug from specifically designed gold nano-carriers. In parallel, we have also investigated the mechanisms that lead to this phenomena, and demonstrated the substantial role of nonlinear photoionization in the observed cell damage. For conducting these therapeutic approaches within the body, we have developed several novel aspects of spectrally encoded imaging to allow new optical microscopy techniques feasible for clinical diagnosis and for guiding therapy. Ultra-miniature endoscopic probes were constructed and studied for minimally invasive imaging in hard-to-reach areas, and a novel high-resolution microscopy technique was shown capable of imaging flowing blood cells within patients. Future research will attempt to combine our nano-plasmonic therapeutic approaches with minimally invasive image guidance for targeting early and advanced stage cancers that could not be threated using conventional therapies.