Decellularized biohybrid nerve promotes motor axon projections

Abstract

Developing nerve grafts with intact mesostructures, superior conductivity, minimal immunogenicity, and improved tissue integration is essential for the treatment and restoration of neurological dysfunctions. A key factor is promoting directed axon growth into the grafts. To achieve this, we developed biohybrid nerves using decellularized rat sciatic nerve modified by in situ polymerization of poly(3,4-ethylenedioxythiophene) (PEDOT). We compared nine biohybrid nerves with varying polymerization conditions and cycles, selecting the best candidate through material characterization. Our results showed that a 1:1 ratio of FeCl3 oxidant to ethylenedioxythiophene (EDOT) monomer, cycled twice, provided superior conductivity (>0.2 mS/cm), mechanical alignment, intact mesostructures, and high compatibility with cells and blood. To test the biohybrid nerve's effectiveness in promoting motor axon growth, we used human Spinal Cord Spheroids (hSCSs) from HUES 3 Hb9:GFP cells, with motor axons labeled with green fluorescent protein (GFP). Seeding hSCS onto one end of the conduit allowed motor axon outgrowth into the biohybrid nerve. Our construct effectively promoted directed motor axon growth, which improved significantly after seeding the grafts with Schwann cells. This study presents a promising approach for reconstructing axonal tracts in humans.