Photodynamic Therapy (PDT) is a clinically approved cancer treatment relying on the use of a photosensitizer, i.e., a fluorescent molecule producing cytotoxic species upon irradiation with light. PDT also provides the ability to image and locally treat diseased tissues without ionizing radiations, thus sparing healthy tissue. Yet, only five photosensitizers are now approved for clinical applications and all suffer from serious drawbacks, including low selectivity and skin sensitization.Photosensitizer-loaded nanoparticles could potentially solve these problems. They can accumulate at the site of tumors by either passive or active targeting. Their physicochemical properties can also be tuned to accelerate clearance, and reduce non-specific binding. In this study, we propose to investigate a novel class of polymer-based organic nanoparticles whose most relevant physicochemical properties can easily be tuned by controlling synthesis parameters.Benefiting from expertise of researchers at the Beth Israel Deaconess Medical Center (Boston, MA, United States), the research fellow will design a wide range of polymer fluorescent nanoparticles. These particles will be tested to find a formulation with optimal blood half-life, low non-specific binding and good targeting capabilities. The research fellow will then synthesize and test the most efficient particles at the Institut Albert Bonniot (Grenoble, France) on head and neck tumor rodent models using 2D and 3D fluorescence imaging. The PDT efficacy will be monitored by following tumor growth and survival rate of the animals.This fellowship application has the potential to solve a longstanding problem in PDT while providing outstanding international training and promoting the career of a talented European researcher.