Fabrication of a Highly Conductive Silk Knitted Composite Scaffold by Two-Step Electrostatic Self-Assembly for Potential Peripheral Nerve Regeneration

Abstract

Peripheral nerve injury is a common serious disease, and the electrical conductivity of nerve scaffolds is of special significance for nerve regeneration. Here, a highly conductive silk knitted composite scaffold was prepared by utilizing hydrogen bonding and electrostatic adsorption between silk amino, graphene (RGO), and polyaniline (PANI). Compared to traditional in situ polymerization of aniline (ANI), the surface of the RGO/PANI/silk conductive knitted scaffold prepared by two-step electrostatic self-assembly had more uniform PANI particles and lower resistance; when GO was 1 g/L and ANI was 0.4, 0.6, or 0.8 mol/L, the RGO/PANI/silk scaffold had better electrical properties when the conductivity was between 0.62 × 10–3 and 1.72 × 10–3 S/cm. The scaffolds had good conductive stability under different physical stresses and good mechanical properties, wherein ultimately the strength, elongation at break, and Young’s modulus ranges were 28.07–34.97 MPa, 105.91–109.85%, and 10.2–12.48 MPa, respectively, and so they provided good support. Conductive scaffolds had ordered loops, fiber structure, and large pore sizes between 40 and 70 μm. In summary, RGO/PANI/silk scaffold with good conductivity, pore size distribution, mechanical properties, thermal properties had potential applications in the field of peripheral nerve regeneration.

Conductive fibers for biomedical applications

“…Natural nerve tissue is composed of nerve bundles with multiple aligned assemblies, and transmits information mainly through action potential generated by synapses [ 122 , 123 ]. Hence, the orientation and electroconductivity of the matrix are of great benefits for guiding neuron alignment and transmission of electrical signals [ 124 ].…”

Conventional and Recent Trends of Scaffolds Fabrication: A Superior Mode for Tissue Engineering

“…Each method has its limitations. For example, phase separation yields fibers that lack structural stability [206], template synthesis is a time-consuming process [207], and selfassembly forces narrow biomaterial choices [208]. The most suited technique used in NFs fabrication is electrospinning.…”

Graphene Oxide–Protein-Based Scaffolds for Tissue Engineering: Recent Advances and Applications

“…There have also been several attempts to enhance the electrical properties of silk fibroin/GO bioconjugate. Meng et al [147] introduced polyaniline, a well-known conductive polymer, to this formulation. The synthesis process of the nanocomposite formulation was based on electrostatic interactions between amino functional groups present in the protein backbone and oxygen groups from the basal plane of GO, followed by in situ polymerization of aniline.…”