In Vivo Formation of Organic Bioelectronic Hydrogels

Interfacing electronics with neural tissue is crucial to understand complex biological functions and to combat brain disorders. Novel materials and devices, based on metals and other hard materials, already exist that successfully can monitor and stimulate neural activity. Their development, however, employed from semiconductor industry results in electronics and electrodes with static and bio-incompatible geometries. On the other hand, biological signaling systems are highly interconnected, and they dynamically change their function and structure according to input dynamics. The difference between the static solid-state electronics and the dynamic and soft biological matter makes seamless integration impossible. We developed processes and materials that dynamically create soft electronic conductors at the interface with the biological environment. We utilize enzymes to polymerize organic molecules and to develop conducting polymers upon a specific biological input analogous to protein formation. Functional electroactive trimers, oxidase and peroxidase enzymes all embedded in biopolymers are delivered into the biological tissue. Glucose or lactate that naturally already exist in the receiving tissue is used as the fuel to power polymerization and finally the formation of conducting polymer hydrogels with long range conductivities. We show in vivo polymerization and formation of conducting polymers in zebrafish brain and around the nervous tissue of medicinal leeches. Our approach not only demonstrates formation of conducting polymers with good electrical performance and biocompatibility, but also it introduces a paradigm shift on the development and interface of electronics with biology.