Abstract: The present invention relates to novel compositions and methods for potentiating the activity of biologically active molecules in conjunction with one or more delivery vehicles and one or more carrier molecules. Specifically, the invention features the use of a carrier molecule in combination with a delivery vehicle and a biologically active molecule of interest to potentiate the activity of the biologically active molecule. The carrier molecule can be biologically inert, inactive, or attenuated; or can alternately be biologically active in the same or different manner than the biologically active molecule of interest. Specifically, the invention features novel particle forming delivery agents including cationic lipids, microparticles, and nanoparticles that are useful for delivering various biologically active molecules to cells in conjunction with a carrier molecule.