Abstract
Background & Purpose
Peripheral neuropathy is a common side effect of chemotherapy drugs, yet traditional preclinical models often fail to predict neurotoxicity effectively. To address this, 28bio developed a 3D Nerve-on-a-Chip platform that mimics in vivo nerve fiber anatomy and enables sensitive detection of neurotoxic effects. This platform combines rat dorsal root ganglia (DRG) cultures with a dual hydrogel system to assess morphological and electrophysiological changes in response to neurotoxic compounds.
Methods
- Fabrication & Culture:
- PEG hydrogel scaffolds were printed onto semi-permeable membranes via photolithography.
- Embryonic rat DRG explants were inserted into Matrigel-filled channels and cultured for 4 weeks to facilitate robust 3D axon growth.
- Toxicity Testing:
- Cultures were exposed to known neurotoxic chemotherapeutics for 7 days, including:
- Bortezomib (proteasome inhibitor)
- Oxaliplatin (platinum-DNA adduct formation)
- Paclitaxel (microtubule stabilizer)
- Vincristine (vinca alkaloid targeting microtubule formation)
- Assessment Metrics:
- Electrophysiology Testing: Measured nerve conduction velocity (NCV) and signal amplitude (AMP) as functional markers.
- Cell Viability: Measured via CCK-8 assay for live cell counts and LDH assay for cell death assessment.
- Immunostaining: Measured myelination changes using MBP (myelin marker) and βIII-tubulin (neural marker).
Results
- Electrophysiology Findings:
- Significant reductions in NCV and amplitude were observed before cell viability declined, indicating that functional impairment precedes cell death.
- Paclitaxel and Vincristine showed the most rapid declines in NCV, aligning with known clinical neuropathy patterns.
- Cell Viability & Morphological Analysis:
- All tested drugs reduced cell viability in a dose-dependent manner.
- Immunostaining revealed that myelination was significantly reduced, even when cell counts appeared intact.
Conclusion
The 3D Nerve-on-a-Chip model effectively replicates key aspects of chemotherapy-induced peripheral neuropathy, providing a clinically relevant, sensitive tool for neurotoxicity screening. Functional electrophysiology emerged as a more predictive endpoint than traditional cell viability assays. Future efforts will focus on expanding assay sensitivity and improving electrode designs to enhance data capture for preclinical drug screening applications.
