A Modular Approach to the Design of Embedded Controllers for Chemical Reaction Networks

The definition of a general framework for the control of biomolecular circuits represents a challenging objective in the field of Synthetic Biology. While the methods of Control Theory have long since fruitfully contamined many other fields of science and engineering, like aerospace, communication networks or nanotechnology, their application in Synthetic Biology is mainly hampered by the lack of a modular approach to the realization of embedded biological controllers. In this paper we tackle this problem, devising few basic modules that can be assembled to construct a simple closed-loop feedback control scheme. These modules are composed of a minimal set of simple reactions and their description is given at an abstract level, without focusing on a specific biological implementation. To this aim, we have adopted the formalism of Chemical Reaction Networks (CRNs) with mass-action kinetics. A simulated experiment is presented to show how our approach can be used, at least in an ideal setting, to effectively regulate the output of an in-silico CRN process to a desired value. These results, though preliminary, pave the way to new strategies for the design of synthetic biological systems and, more generally, to the establishment of a general control theory for synthetic biomolecular circuits.