Electrically Conductive Injectable Silk/PEDOT: PSS Hydrogel for Enhanced Neural Network Formation

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Neuroscience

Background:

• Spinal cord injury (SCI) lacks effective treatments for functional recovery.
• Human induced pluripotent stem cell (hiPSC) transplantation offers a patient-specific regenerative approach.
• Injectable electroconductive hydrogels (ECHs) can enhance cell transplantation and mimic neural tissue's bioelectrical environment.

Purpose of the Study:

• To develop a novel injectable electroconductive hydrogel (ECH) for enhanced spinal cord injury (SCI) repair.
• To evaluate the ECH's properties and its efficacy in supporting encapsulated stem cells for neural regeneration.

Main Methods:

• Fabrication of an ECH via in situ gelation of silk fibroin (SF) and pre-stabilized PEDOT:PSS.
• Characterization of ECH injectability, mechanical properties (elastic modulus, shear-thinning), and electrical conductivity.
• Assessment of hiPSC-derived neural cell survival, maturation, and network formation within the ECH.

Main Results:

• The novel SF/PEDOT:PSS ECHs are injectable, possess suitable mechanical properties comparable to spinal cord tissue, and exhibit good structural recoverability.
• ECHs demonstrate electrical conductivity mimicking the native neural environment.
• Encapsulated hiPSC-derived cortical neurons and astrocytes show high survival rates (>80%) and supported neuronal maturation and synaptogenesis.

Conclusions:

• The developed silk-based ECH is a promising biomaterial for cell transplantation in spinal cord regeneration.
• The ECH's properties effectively support stem cell survival and neural network development, indicating potential for functional recovery after SCI.