By adapting the methods of layer-by-layer (LbL) from large surfaces to nanoparticles, it is possible to gain many of the same advantages described above toward the design of nanoparticles that can target cancer based on size and molecular targeting, while enabling the release of multiple agents optimized to achieve maximum impact and synergistic cancer cell death. Recently, the Hammond lab began to apply these LbL concepts to nanoparticles to address the targeting of cancer. The nanoparticle systems can be tuned to release an agent such as an inhibitor or siRNA that blocks the defense mechanisms of tumors, followed by delivery of a chemotherapy drug that can then exhibit enhanced efficacy. Additional approaches include micellar assemblies with siRNA and ligand-cluster dendritic block copolymers that provide a means of enhanced targeting. The lab has recently investigated concatenated siRNA approaches using rolling circle transcription toward the design of self-generated porous polymeric RNA microcarriers, which break down into short siRNA strands once within the targeted cells, to yield highly potent and concentrated doses of siRNA.