Filament Extrusion-Based Conductive TPU Composite Scaffolds Enable Superior Neuronal Growth and Synaptic Maturation...

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Neuroscience

Background:

• Fused filament fabrication (FFF) three-dimensional (3D) printing offers customizable, low-cost platforms for tissue engineering.
• Conductive thermoplastic polyurethane (cTPU) is a promising material for bioelectronic applications.
• Characterizing soft viscoelastic materials requires efficient and accurate methods.

Purpose of the Study:

• To develop and characterize 3D-printed cTPU scaffolds using FFF technology.
• To evaluate the mechanical, electrical, and biological performance of cTPU scaffolds in vitro.
• To assess the suitability of cTPU scaffolds for neural tissue modeling and bioelectronic interfaces.

Main Methods:

• Fabrication of 3D-printed scaffolds using cTPU filaments via FFF.
• Dynamic mechanical analysis (DMA) to assess temperature- and rate-dependent mechanical properties.
• Electrical conductivity measurements, surface characterization (hydrophilicity, roughness), and in vitro cell culture (MEFs and hippocampal neurons) with immunofluorescence analysis (MAP-2, PSD-95).

Main Results:

• cTPU scaffolds exhibited enhanced mechanical stiffness, stable conductivity (∼1-2 mS/cm), increased hydrophilicity, and higher nanoscale roughness compared to TPU.
• Mouse embryonic fibroblasts (MEFs) showed high viability (>85%) and proliferation on both scaffolds.
• Hippocampal neurons cultured on cTPU scaffolds demonstrated significantly enhanced neuronal network density, synaptic maturation (MAP-2, PSD-95 expression), supporting long-term growth.

Conclusions:

• FFF 3D-printed cTPU platforms are cost-effective, tunable, cytocompatible, and electrically active.
• cTPU scaffolds effectively support neuronal growth, network formation, and synaptic maturation.
• These findings position cTPU composites as promising materials for neural tissue modeling and bioelectronic interfaces.