In the context of a collaboration with physicists from the Institut de Physique de Nice INPHYNI (Gian Luca Lippi from the complex photonic systems and materials group), we study the simultaneous action of stimulated emission and multiple scattering by randomly distributed nanoparticles in a bulk medium. The ultimate goal is to develop a time-domain numerical methodology for the simulation of random lasing in a biocompatible gain medium.