3D-Printed Stent-Like Polymeric Structures with Tunable Mechanical Properties and Ionic Conductivity for Reinforced...

Peripheral nerve injuries present a critical clinical challenge, particularly when bridging larger defects that exceed the capacity of conventional grafts. Although electrospun poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) nerve guidance conduits (NGCs) provide a promising solution due to their piezoelectric properties and extracellular matrix-mimicking structure, in electrospun scaffold form, they lack the mechanical strength to resist luminal collapse and compressive forces from surrounding tissues. Here, we report a stent-inspired approach to reinforce PVDF-TrFE conduits by integrating 3D-printed polymer lattices composed of poly(ethylene glycol) diacrylate (PEGDA) and ethylene glycol polyether acrylate (EGPEA). By modulating the EGPEA:PEGDA ratio, we tailored the mechanical stiffness, swelling behavior, and ionic conductivity of the photocurable resin, yielding structural designs that effectively support PVDF-TrFE conduits. Mechanical testing and finite element analysis (FEA) demonstrated that hexagonal lattice geometries significantly reduced stress concentrations and enhanced yield strength under physiologically relevant pressures compared to rectangular controls. Additionally, the PEG moieties facilitated ion transport through the reinforcement structures, a property with the potential to modulate the local electrochemical environment and amplify the piezoelectric advantages of PVDF-TrFE. We demonstrated the resin's biocompatibility through fibroblast assays, showing no significant reduction in cell viability or morphological disruption compared to controls following a 24-h ethanol wash. Taken together, this work establishes a material-level proof-of-concept that integrates mechanical reinforcement with ionic transport in a piezoelectric conduit platform for enhanced peripheral nerve regeneration.