Cell-Free Synthetic Biology Platform for Engineering Synthetic Biological Circuits and Systems

Abstract

Synthetic biology integrates diverse engineering disciplines to create novel biological systems for biomedical and technological applications. The substantial growth of the synthetic biology field in the past decade is poised to transform biotechnology and medicine. To streamline design processes and facilitate debugging of complex synthetic circuits, cell-free synthetic biology approaches has reached broad research communities both in academia and industry. By recapitulating gene expression systems in vitro, cell-free expression systems offer flexibility to explore beyond the confines of living cells and allow networking of synthetic and natural systems. Here, we review the capabilities of the current cell-free platforms, focusing on nucleic acid-based molecular programs and circuit construction. We survey the recent developments including cell-free transcription–translation platforms, DNA nanostructures and circuits, and novel classes of riboregulators. The links to mathematical models and the prospects of cell-free synthetic biology platforms will also be discussed.

Multilevel Gene Regulation Using Switchable Transcription Terminator and Toehold Switch in Escherichia coli

“…Our experiments demonstrated SWT as switchable control elements for transcriptional regulation that can complement STAR transcription regulators and enrich the toolbox of RNA synthetic biology [55]. Due to the working mechanism that terminates transcription of the downstream gene in its off state, the resource burden on the host organisms is minimized while achieving tight leakage control.…”

Cell-free riboswitches

“…1G). These RNA/DNA-responsive cell-free switches have been used to prototype genetic circuits [63][64][65][66] and to develop biosensors for detecting RNAs from viruses, 67,68 bacteria, 69 and a variety of RNA markers. 69,70 4.…”

Biological Materials: The Next Frontier for Cell-Free Synthetic Biology

“…As an exemplar, the same authors reported on the development of smart materials, inspired by synthetic biology logic circuits, that can detect novobiocin antibiotics (Wagner et al, 2019). These, as well as many other transcriptional and translational regulatory mechanisms can be combined into highly complex cell-free executable circuit designs (Jeong et al, 2019). Therefore, it is conceivable that these studies might inspire future efforts to embed cell-free executable logic circuits within a broad array of synthetic biology-based smart materials.…”