A model of spatio-temporal regulation within biomaterials using DNA reaction–diffusion waveguides

In multi-cellular organisms, cells and tissues coordinate biochemical
signal propagation across length scales spanning micrometres to metres.
Designing synthetic materials with similar capacities for coordinated
signal propagation could allow these systems to adaptively regulate
themselves across space and over time. Here, we combine ideas from cell
signalling and electronic circuitry to propose a biochemical waveguide
that transmits information in the form of a concentration of a DNA species
on a directed path. The waveguide could be seamlessly integrated into a
soft material because there is virtually no difference between the
chemical or physical properties of the waveguide and the material it is
embedded within. We propose the design of DNA strand displacement
reactions to construct the system and, using reaction-diffusion models,
identify kinetic and diffusive parameters that enable super-diffusive
transport of DNA species via autocatalysis. Finally, to support
experimental waveguide implementation, we propose a sink reaction and
spatially inhomogeneous DNA concentrations that could mitigate the
spurious amplification of an autocatalyst within the waveguide, allowing
for controlled waveguide triggering. Chemical waveguides could facilitate
the design of synthetic biomaterials with distributed sensing machinery
integrated throughout their structure and enable coordinated
self-regulating programmes triggered by changing environmental conditions.