A Programmable, 3D Neuron‐On‐Chip Platform Integrating Near Real‐Time Biosensing and Multiaxial Loading for Mechanobiological Injury Profiling

Mechanical forces imparted to the central nervous system (CNS) generate complex, load-dependent injury patterns, yet the molecular mechanisms linking physical insult to biomarker response remain poorly defined. Here, the Neuron-Injury-on-a-Chip (NIOC) platform is presented as a programmable 3D microfluidic system integrating multiaxial loading with real-time biosensing. The system features a polydimethylsiloxane (PDMS) tube internally coated with polydopamine to support Cath. a-differentiated (CAD) neuron adhesion and viability. Controlled extension, torsion, and combined loads simulate physiologically relevant CNS trauma. Finite element modeling confirms uniform strain transmission, while embedded electrochemical biosensors enable near real-time detection of total tau (T-Tau) and neurofilament light chain (NFL) at picogram levels. qPCR and immunostaining validate gene-level responses (Mapt, Gap-43) and apoptosis (Caspase-3). Load-specific biomarker trajectories and apoptotic thresholds are uncovered, with synergistic injury responses under combined loading. NIOC represents a first-in-class platform for decoding mechanobiological injury, offering new opportunities for biomarker discovery, injury stratification, and neuroprotective screening.