We propose the development of multi-functional composite particles for use as improved DNA delivery vehicles in biolistic applications. These particles will be fabricated using the controlled assembly of nanoparticles, polymers, and biomolecules via a layer-by-layer technique where the core and each subsequent layer add specific functionality to the final particle. The density, stability, surface area, and surface chemical composition will be controlled by the choice of material and dimensions of the core and surrounding shell layers. When these novel nano-fabricated devices are used in biolistic applications, the efficacy and reproducibility of the procedure will be greatly enhanced. These novel nanoparticles will be of broad interest to users of biolistic transfection systems in both academic and commercial research communities.