What does this research mean for the field?

PEDOT:PSS-based Organic Electrochemical Transistors (OECTs) maintain their operational functionality when covered by protein layers and cells associated with the Foreign Body Reaction (FBR), indicating they can resist fibrotic responses without requiring anti-FBR strategies. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.ESTABLISHES_NEW_DIRECTION.

What question did this study set out to answer?

This research aims to assess how the foreign body reaction affects the performance of organic electrochemical transistors during implantation.

March 25, 2026Open Access

Organic Electrochemical Transistors and Foreign Body Reaction: First Steps Toward Long‐Term Implantable Biosensing

Key Points

This research aims to assess how the foreign body reaction affects the performance of organic electrochemical transistors during implantation.
Analyzed the performance of PEDOT:PSS based OECTs covered with protein layers associated with the foreign body reaction.
Conducted in vitro evaluations to observe the effects of albumin, collagen, and fibrinogen on OECT functionality.
Tested OECT resilience to coverage with yeast cells to simulate a wound healing process.
Protein coverage slightly increased switching time but did not significantly impede OECT operation.
Yeast cell coverage also maintained the functionality of OECTs, indicating robustness against foreign body reactions.

Abstract

ABSTRACT Organic Electrochemical Transistors (OECT) have been widely used to detect a myriad of analytes and signals, ranging from glucose content in sweat to brain epileptiform activity. Due to their biocompatibility, small footprint, conformability, and high signal amplification, OECTs can not only be used in wearable, but also in implanted sensor systems, providing superior signal quality. However, although there is a risk of triggering the Foreign Body Reaction (FBR) with implantation, FBR impact on OECTs has rarely been discussed. Therefore, here we evaluate the effect of the FBR fibrotic response on OECT performance, i.e. when the OECT is covered by protein layers, in vitro. In more detail, we analyze poly(3,4‐ethylenedioxythiophene):poly (styrene‐sulfonate) (PEDOT:PSS) based OECTs and intentionally cover their channels with protein layers commonly formed during FBR, such as albumin, collagen and fibrinogen. Despite slightly increasing devices' switching time, proteins do not hamper their operation. Further coverage by yeast cells as a proof of concept of wound healing process also did not jeopardize OECT functioning, indicating devices could resist the FBR fibrotic response without anti‐FBR strategies.

Organic Electrochemical Transistors and Foreign Body Reaction: First Steps Toward Long‐Term Implantable Biosensing

Key Points

Abstract

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