PAA (polyacrylic acid and its derivatives at the carboxy groups, e.g. polyacrylamide) nanoparticles containing a photosensitizer and an imaging enhancing agent are provided. The imaging agent is preferably a PET imaging agent and more preferably an 1241 labeled compound. The photosensitizer is preferably selected from chlorins, bacteriochlorins, pyropheophorbides, and mixtures thereof. The nanoparticles preferably contain at least one photosensitizer comprises a moiety containing 1241 and also acts as an imaging agent. The photosensitizer and imaging agent are preferably post loaded onto the nanoparticle after nanoparticle formation.La présente invention concerne des nanoparticules PAA contenant au moins un photosensibilisateur tétrapyrrolique et au moins un agent dimagerie TEP.
