# Blood-Catalyzed Polymerization Creates Conductive Polymer in Live Zebrafish

## TL;DR

Scientists created a conductive polymer inside live zebrafish embryos using blood, which could lead to new biomedical applications.

## Contribution

First in vivo synthesis of a conductive polymer using whole blood in live zebrafish embryos.

## Key findings

- n-PBDF was successfully synthesized in zebrafish embryos through blood-catalyzed polymerization.
- In cellulo formed n-PBDF improved bio-interfaces and light-induced neural activation in cultured neurons.
- Whole blood was confirmed as an effective catalyst for polymerization in vitro before in vivo application.

## Abstract

Conducting polymers are of great interest in bioimaging, bio-interfaces, and bioelectronics for their biocompatibility and the unique combination of optical, electrical, and mechanical properties. They are typically prepared outside through traditional organic synthesis and delivered into the biological systems. The ability to call for the polymerization ingredients available inside the living systems to generate conducting polymers in vivo will offer new venues in future biomedical applications. This study is the first report of in vivo synthesis of an n-doped conducting polymer (n-PBDF) within live zebrafish embryos, achieved through whole blood catalyzed polymerization of 3,7-dihydrobenzo[1,2-b:4,5-b′]difuran-2,6-dione (BDF). Prior to this, the efficacy of such a polymerization was rigorously established through a sequence of in vitro experiments involving Hemin, Hemoproteins (Hemoglobin, Myoglobin, and Cytochrome C), red blood cells, and the whole blood. Ultimately, in cellulo formed n-PBDF within cultured primary neurons demonstrated enhanced bio-interfaces and led to more effective light-induced neural activation than the prefabricated polymer. This underscores the potential advantages of synthesizing conducting polymers directly in living systems for biomedical applications.