Abstract

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This study presents a novel 3D, dual-hydrogel culture system that enables physiologically relevant in vitro modeling of peripheral nerve tissue. Using dorsal root ganglia (DRG) explants in a spatially confined construct, the system allows for detailed electrophysiological recordings including compound action potentials (CAPs) and nerve fiber density (NFD)—mirroring clinical diagnostics. This platform overcomes limitations of traditional 2D or non-functional models by mimicking both the architecture and function of native afferent nerve tissue. These findings pave the way for more predictive and translational preclinical testing methods.

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Key Learnings

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• Functional Relevance: The model reliably produces CAPs and supports single-neuron and population-level electrophysiological recordings—mirroring in vivo testing.
• 3D Structure Fidelity: Parallel, fasciculated axonal tracts within a dual-hydrogel environment approximate native nerve morphology.
• Drug Response Testing: Sodium channel blockers like TTX eliminated action potentials, confirming biologically driven signal transmission.
• Synapse-Free Design: Glutamate receptor antagonists had no effect, indicating direct axonal conduction in the model.
• Extended Culture Potential: Cultures were viable for weeks, supporting long-term assays and possible myelination studies.

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Methods

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The platform incorporates:

• Dual Hydrogel Fabrication: PEG boundaries and Puramatrix channels confine DRG growth into aligned neural tracts.
• DRG Explant Integration: Rat embryonic DRG explants are cultured into the 3D constructs to promote neural outgrowth.
• Electrophysiological Assessment: Field potentials and whole-cell patch clamp techniques evaluate CAPs and neuron excitability.
• Microscopy: Confocal imaging and TEM verify cellular structure, axon growth, and fasciculation.
• Drug Validation: TTX and glutamate receptor antagonists assess response specificity and validate signal pathways.

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Conclusions

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This nerve-on-a-chip model replicates the structure and function of peripheral nerve tissue and enables reliable electrophysiological measurements. It serves as a robust medium-throughput platform that bridges the gap between traditional cell culture and animal models. With its biomimetic design, the system is poised to improve drug safety testing, toxicity profiling, and therapeutic development in neuroscience.

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Reference

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Huval RM, Miller OH, Curley JL, Fan Y, Hall BJ, Moore MJ. Microengineered peripheral nerve-on-a-chip for preclinical physiological testing. Lab Chip. 2015;15(11):2221-2232. doi:10.1039/c4lc01513d