# Exploring the role of directly coupled alternating electric fields on chondrocyte morphology and redifferentiation capacity with a focus on sex differences

**Authors:** Zezhong Song, Vivica Freiin Grote, Franziska Sahm, Julius Zimmermann, Christoph Lutter, Anika Jonitz‐Heincke, Rainer Bader

PMC · DOI: 10.1002/jeo2.70261 · 2025-05-06

## TL;DR

This study shows that electrical stimulation can help chondrocytes redifferentiate, with male cells responding better than female cells.

## Contribution

The study reveals sex-based differences in chondrocyte response to electric fields, offering insights for cartilage repair therapies.

## Key findings

- Electric fields at 15–20 V/m increased the Col2/Col1 ratio and chondrocyte-like morphology.
- Female chondrocytes showed higher Col1 synthesis and a lower Col2/Col1 ratio compared to male cells.
- Male chondrocytes were more prone to redifferentiate after electrical stimulation.

## Abstract

In cell‐based therapies addressing articular cartilage lesions, a central challenge is to avoid the formation of fibrous cartilage resulting from dedifferentiation processes. Electrical stimulation emerges as a promising approach for promoting chondrocytic redifferentiation. This study investigated the effects of varying electric fields on morphological changes and the redifferentiation capacity of human chondrocytes with regard to alterations in sex.

Chondrocytes, isolated from the articular cartilage of male and female patients undergoing total knee replacement, were exposed to alternating electric fields of varying strengths ranging from 0.8 to 1.2, 15 to 20 and 100 to 140 V/m. Afterwards, cell morphology and viability, as well as the deposition of collagen (Col) 1 and 2, were evaluated.

Following electrical stimulation, in particular at 15–20 V/m, an increase in the Col2/Col1 ratio and an elevated proportion of rounded, chondrocyte‐like cell morphology were observed, indicating a promoting effect on the redifferentiation of chondrocytes. Comparative analysis between both sexes revealed that chondrocytes from female donors exhibit higher Col1 synthesis rates, a decreased Col2/Col1 ratio, and a higher proportion of elongated, fibroblast‐like cells compared to chondrocytes derived from male donors.

Our in vitro study suggests that chondrocytes from male donors are more prone to re‐differentiate after electrical stimulation.

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## Linked entities

- **Species:** Homo sapiens (taxon 9606)

## Full-text entities

- **Species:** Homo sapiens (human, species) [taxon 9606]

## Figures

4 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12053005/full.md

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Source: https://tomesphere.com/paper/PMC12053005