Abstract: The invention relates to amphiphilic Janus dendrimers which may form nanoparticles. The invention also relates to methods of inducing an adaptive immune response in a subject comprising administering to the subject an effective amount of a composition comprising at least one nucleoside-modified RNA encoding at least one antigen and at least one amphiphilic Janus dendrimer and to methods of delivering an agent to a subject in need thereof, said method comprising the step of delivering to the subject a composition comprising an agent encapsulated by a nanoparticle.