Mimicking Nature with Constitutional Dynamic Networks

Abstract

Numerous biological transformations operate by complex networks that are activated by external triggers, such as light, pH changes, chemical inputs, and more. The operations of natural networks can involve feedback processes, inter communication between networks coupling of networks, and more. Specifically, the operation of networks in nature may lead to sensing events, programmed catalysis, and logic operations mimicking computing circuits.

The “holy grail” of chemists and the field of “Systems Chemistry” define the challenge to construct artificial systems mimicking such networks. Our laboratory addresses these challenges by applying nucleic acids (DNA) as active material to assemble constitutional dynamic networks (CDNs) that mimic the properties and functions of biological networks. The base sequence of nucleic acids encodes structural and functional information that allows the control over the stability of the nucleic acid structures, as well as the programmability and reconfiguration of DNA structures by external triggers such as formation of triplexes, G-quadruplexes or light. These unique properties of nucleic acids are used to develop constitutional dynamic networks (CDNs). This will be addressed in the talk by introducing the following topics:

  1. a) The simplest equilibrated network consisting of four dynamically exchangeable constituents will be introduced. The stimuli-triggered reconfiguration of the equilibrated network by external triggers will be demonstrated.
  2. b) Constitutional dynamic networks of enhanced complexities will be introduced. These include the inter-communication between networks, feedback-driven networks and network-in-networks systems.
  3. c) Possible applications of constitutional dynamic networks will be highlighted. These include the use of CDNs for operating logic gates and computing circuits, and the use of CDNs as supramolecular “devices” to assemble new materials, such as hydrogels of controlled stiffness and hydrogels exhibiting self-healing properties.
  4. d) The future perspectives and challenges of the field will be briefly mentioned.