Interactive Materials for Bidirectional Redox‐Based Communication

• Published in: Advanced materials (Weinheim) 2021-05, Vol.33 (18), p.e2007758-n/a
• Main Authors: Li, Jinyang, Wang, Sally P., Zong, Guanghui, Kim, Eunkyoung, Tsao, Chen‐Yu, VanArsdale, Eric, Wang, Lai‐Xi, Bentley, William E., Payne, Gregory F.
• Format: Article
• Language: English
• Subjects: Aquatic plants; Catechol; catechols; Catechols - chemistry; Chemical synthesis; Communication; E coli; electrobiofabrication; Electrons; electro‐biofabrication; Escherichia coli; extracellular electron transfer; Gene expression; Hydrogels; Hydrogels - chemistry; Hydrogen peroxide; Hydrogen Peroxide - chemistry; interactive materials; MATERIALS SCIENCE; Oxidation-Reduction; Polyethylene glycol; Polyethylene Glycols - chemistry; redox signaling; Reducing agents; Signaling
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202007758

Emerging research indicates that biology routinely uses diffusible redox‐active molecules to mediate communication that can span biological systems (e.g., nervous and immune) and even kingdoms (e.g., a microbiome and its plant/animal host). This redox modality also provides new opportunities to create interactive materials that can communicate with living systems. Here, it is reported that the fabrication of a redox‐active hydrogel film can autonomously synthesize a H2O2 signaling molecule for communication with a bacterial population. Specifically, a catechol‐conjugated/crosslinked 4‐armed thiolated poly(ethylene glycol) hydrogel film is electrochemically fabricated in which the added catechol moieties confer redox activity: the film can accept electrons from biological reductants (e.g., ascorbate) and donate electrons to O2 to generate H2O2. Electron‐transfer from an Escherichia coli culture poises this film to generate the H2O2 signaling molecule that can induce bacterial gene expression from a redox‐responsive operon. Overall, this work demonstrates that catecholic materials can participate in redox‐based interactions that elicit specific biological responses, and also suggests the possibility that natural phenolics may be a ubiquitous biological example of interactive materials. A redox‐active catechol‐based film can autonomously synthesize diffusible H2O2 signals that enable interactive communication with biology. The reducing redox activities of a bacterial culture provide the electrons that poise this film for subsequent electron‐donation to O2 to generate the H2O2 signaling molecule that induces redox‐responsive gene expression.