Electroconductive poly(3,4‑ethylenedioxythiophene) (PEDOT) nanoparticle‑loaded silk fibroin biocomposite conduits for peripheral nerve regeneration

Abstract

Peripheral nerve injury (PNI) often clinically relies on the use of nerve grafts taken from the patient to establish a therapeutic effect, though secondary site of injury and morbidity have prompted the medical community to find alternative solutions. A new trend in the development of biomaterials arises in the form of electro-conductive biomaterials, especially for electrically active tissues such as the peripheral nerves. In this work, novel poly(3,4-ethylenedioxythiophene) PEDOT nanoparticles (PEDOT NPs) were synthetized via the mini-emulsion method and were combined with silk fibroin (SF) to create conduits for PNI repair. The synthesized PEDOT NPs-loaded SF conduits showed optimal properties for peripheral nerve substitution from the physico-chemical and biological point of view. They displayed excellent mechanical and conductivity performance with the tensile moduli reaching 6.61â ±â 0.55 MPa and the conduits reaching 5.4 · 10â 4 S cmâ 1, respectively. The conduits did not possess apatite-forming capacity, which were resistant to bending occlusions for angles up to 50° and to suturing. The developed conduits are promising as a novel biomaterial for applications in peripheral nerve regeneration; in vitro experiments showed that they did not allow BJ fibroblast infiltration, avoiding scar tissue formation in the lumen, and they did not show any toxic effect for Schwann cells.