Abstract
Background & Purpose
Peripheral neuropathy is challenging to model in vitro due to the complex architecture and functional requirements of nerves, including Schwann-cell myelination and electrophysiological signaling. The NerveSim® 3D nerve-on-a-chip system was developed to address these challenges by using human iPSC-derived sensory neurons (hSNs) and primary human Schwann cells (hSCs) in a microphysiological system (MPS). This study aims to validate neurite outgrowth, Schwann cell migration, myelination, and functional electrophysiology to support drug screening for neurotoxicity and neuroprotection.
Methods
- Fabrication: PEG hydrogel scaffolds were crosslinked onto permeable membranes to create 3D nerve-on-a-chip structures.
- Cell Culture: hSN-hSC spheroids were cultured within the microchannel for 28 days, mimicking natural nerve fiber growth.
- Histological & Imaging Analysis:
- Immunohistochemistry (IHC): Measured neurite length, Schwann cell migration, and myelination.
- Transmission Electron Microscopy (TEM): Analyzed axonal ultrastructure.
- Electrophysiology Testing:
- Embedded Electrode Arrays (EEAs): Used for current stimulation and recording compound action potentials (CAPs).
- Functional Response to Capsaicin & Vincristine: Measured spike rates and nerve conduction velocity (NCV).
Results
- Histological Validation:
- Neurite outgrowth >7mm, Schwann cell axonal alignment, and myelination confirmed by TEM and IHC.
- Electrophysiological Response:
- Capsaicin application increased spontaneous electrophysiological activity, demonstrating pain-related TRPV1 expression.
- Vincristine dosing caused dose-dependent declines in nerve conduction velocity, mimicking axonopathy.
- Functional Insights:
- Electrophysiology matched clinical metrics, making NerveSim® a predictive tool for human nerve responses.
Conclusion
The NerveSim® 3D nerve-on-a-chip platform successfully models human peripheral nerve function, making it a valuable tool for drug discovery, neurotoxicity assessment, and neuroprotection screening. Future studies aim to expand compound screening libraries to predict drug mechanisms based on electrophysiology data.
