We review our work on several strategies to elaborate multifunctional nanoparticules for two-photon imaging or/and photodynamic therapy. Our first strategy is based on the incorporation of two-photon hydrophobic fluorophors in bio-compatible pluronic micelles using the mini-emulsion technique. Our second strategy is based on fluorescent organic nanocrystal grown in silicate spheres. These core-shell hybrid nanoparticles are obtained by a spray-drying process from sol-gel solutions. Our third strategy consists in the encapsulation of hydrophilic molecules in the water core of gold nanospheres. They are obtained by a stabilized emulsion in biphasic liquid-liquid medium without surfactant.