Self‐Doped and Biodegradable Glycosaminoglycan‐PEDOT Conductive Hydrogels Facilitate Electrical Pacing of iPSC‐Derived Cardiomyocytes

The electrical properties and performance of conductive hydrogels based on sulfated-glycosaminoglycan-PEDOT (poly 3,4-ethylenedioxythiophene) brush copolymers is studied, showing that the higher sulfation degree of heparin confers hydrogels with the highest conductivity. Heparin-PEDOT hydrogels facilitate the electrical pacing of iPSC-derived cardiomyocytes, can be injected into the heart and show tunable biodegradation.

Abstract

Conductive polymers hold promise in biomedical applications owing to their distinct conductivity characteristics and unique properties. However, incorporating these polymers into biomaterials poses challenges related to mechanical performance, electrical stability, and biodegradation. This study proposes an injectable hydrogel scaffold composed of a self-doped conductive polymer, constituted of a sulfated glycosaminoglycan (GAG) with side chains of PEDOT (poly 3,4-ethylenedioxythiophene). This brush copolymer is synthesized via oxidative polymerization from an EDOT monomer grafted onto the backbone of the sulfated GAG. The GAG backbone offers biodegradability, while sulfate groups act as acidic self-doping agents. Conductive hydrogels form through oxime crosslinking, initially existing as a liquid mixture that undergoes gelation within the tissue, allowing for injectability. The conductive hydrogels show tunable stiffness and gelation kinetics influenced by both concentration and pH, and exhibit adhesive properties. They showcase dual ionic and electronic conductivity, where sulfate groups in the GAG backbone act as doping moieties, enhancing conductivity and electrical stability. These properties of conductive hydrogels are associated with the facilitation of electrical pacing of iPSC-cardiomyocytes. Furthermore, hydrogels exhibit biodegradation and show evidence of biocompatibility, highlighting their potential for diverse biomedical applications.