Conducting Polymer Nanoparticles with Intrinsic Aqueous Dispersibility for Conductive Hydrogels

Abstract

Conductive hydrogels are promising materials with mixed ionic‐electronic conduction to interface living tissue (ionic signal transmission) with medical devices (electronic signal transmission). Beyond signal transduction, the hydrogel form factor also uniquely bridges the wet and soft biological environment with the dry and hard environment of electronics. The synthesis of such hydrogels for bioelectronics requires scalable, biocompatible fillers with high electronic conductivity and compatibility with common aqueous hydrogel formulations/resins. Despite significant advances in the processing of carbon nanomaterials (graphene, graphene oxide, carbon nanotubes), fillers that satisfy all these requirements are lacking. Herein, intrinsically dispersible acid‐crystalized PEDOT:PSS nanoparticles (ncrys‐PEDOTX) are reported which are processed through a facile and scalable non‐solvent induced phase separation (NIPS) method from commercial PEDOT:PSS without complex instrumentation. The particles feature conductivities of up to 410 S cm−1, and when compared to other common conductive fillers, display remarkable dispersibility, enabling homogeneous incorporation at relatively high loadings within diverse aqueous biomaterial solutions without additives or surfactants. The aqueous dispersibility of the ncrys‐PEDOTX particles also allows simple incorporation into resins designed for microstereolithography without sonication or surfactant optimization; complex biomedical structures with fine features (< 150 μm) were printed with up to 10% loading of conductive particles. The ncrys‐PEDOTX particles overcome the challenges of traditional conductive fillers, providing a scalable, biocompatible, plug‐and‐play platform for soft organic bioelectronic materials.This article is protected by copyright. All rights reserved

Decellularized biohybrid nerve promotes motor axon projections

“…For the live-dead assay, the following procedure was followed [99][100][101][102]: L929 cells, derived from L-connective mouse tissue strain, were obtained from ATCC (Cat no. CCL-1) and seeded onto nerve samples using a dynamic bioreactor, as previously described [103].…”

3D printed bioelectronic scaffolds with soft tissue-like stiffness

“…Given the aforementioned advantages for control of scaffold properties and engineering cell-material interactions, we sought to fabricate scaffolds by 3D printing PEDOT:PSS hydrogels. In the past few years, several methods have been developed for extrusion-based [24][25][26][27][28][29][30][31][32][33][34] or light-based [35][36][37] 3D printing PEDOT:PSS hydrogels. However, the majority of these studies utilize 3D printing for patterning on substrates resulting in 2D conformable electrodes for implantable or wearable applications rather than for 3D in vitro interfacing.…”

One Pot Photomediated Formation of Electrically Conductive Hydrogels

“…However, photoprinting conductive hydrogels is still a challenging task because the conductive polymer absorbs UV light which may prevent photoactivation and cross-linking. To address this challenge, several studies have reported the fabrication of composite hydrogels of PEDOT:PSS and polyethylene glycol diacrylate (PEGDA) as a photocurable cross-linker using a visible-light photoinitiator system. ,− The resulting hydrogels are patternable but usually show low electrical conductivity, likely due to low loadings of conductive polymer in an insulating scaffold. Instead, Wei et al recently reported the preparation of 3D-printed conductive hydrogels by photopolymerization of the EDOT monomer .…”