Synthetic biology, which has the potential to provide genetic circuits with greatly improved output control over traditional pharmaceuticals, has remained DNA-centered, and genetic circuit design always relies exclusively or partially on transcriptional regulation. However, messenger RNA (mRNA), as a platform for gene transfer, has numerous advantages over plasmid DNA, including the lack of requirement for crossing the nuclear envelope and has negligible risk of genomic integration, making it a significantly safer alternative. However, no control mechanisms have been developed to regulate replicon-based expression. Efforts to engineer post-transcriptional devices based on microRNA, aptamers, or aptazymes have been characterized to have a very low dynamic range and have resulted in devices not suitable for construction of scalable circuits. This technology is the successful construction of synthetic circuits using RNA and RNA binding proteins (RBPs).