Miniature computers capable of performing complex computations have been created by researchers at Arizona State University from ribonucleic acid (RNA).
The living computers have potential to revolutionize intelligent drug design, could be used to help deliver smart drugs or incorporated into medical nanomachines.
Professor Alex Green, lead researcher for the study, used computer software to design various RNA sequences that would have a specific effect in cells. The RNS circuits mimic conventional electronic circuits and are capable of self-assembly in bacterial cells. The base-pairing properties of RNS ensures predictable self-assembly in living cells.
Green said, “We’re using very predictable and programmable RNA-RNA interactions to define what these circuits can do.” The circuits are logic gates that respond to messages – fragments of RNA – which then attach to complimentary cellular circuits, activating the logic gate and performing the desired action. In this case, the assembly of a protein.
As with a computer that can perform complex calculations, these RNA switches can be combined and can evaluate multiple conditions and variables to determine when an output is required. The circuits can also trigger a sequence of actions to achieve the final result. The researchers demonstrated it was possible to carry out a complex combination of AND, OR and NOT logic in a ribocomputing device using RNA toehold switches.
Since the process uses RNA, a universal molecule of life, the technique can be used to regulate protein production in any number of organisms. The technique can be applied to virtually any RNA input. The circuits therefore have potential for use in the treatment or management of a wide range of diseases.
The researchers aim to produce neural networks inside cells using RNA toehold technology and create circuits capable of analyzing various excitatory and inhibitory inputs using programmable molecular signals. They will only produce an output when a preset threshold has been reached, as occurs in other neurons. Potentially, the technology could be developed to allow any human cell to be programmed.
The paper – Complex cellular logic computation using ribocomputing devices – was recently published in Nature.
Image source: Yikrazuul (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons