Instructive electroactive electrospun silk fibroin-based biomaterials for peripheral nerve tissue engineering

Chinnawich Phamornnak; Bing Han; Ben F Spencer; Mark D Ashton; Christopher F Blanford; John G Hardy; Jonny J Blaker; Sarah H Cartmell

doi:10.1016/j.bioadv.2022.213094

Instructive electroactive electrospun silk fibroin-based biomaterials for peripheral nerve tissue engineering

Biomater Adv. 2022 Oct:141:213094. doi: 10.1016/j.bioadv.2022.213094. Epub 2022 Aug 24.

Authors

Chinnawich Phamornnak¹, Bing Han¹, Ben F Spencer¹, Mark D Ashton², Christopher F Blanford³, John G Hardy⁴, Jonny J Blaker⁵, Sarah H Cartmell⁶

Affiliations

¹ Department of Materials and Henry Royce Institute, The University of Manchester, Manchester, United Kingdom.
² Department of Chemistry, Lancaster University, Lancaster, United Kingdom.
³ Department of Materials and Henry Royce Institute, The University of Manchester, Manchester, United Kingdom; Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom; National Graphene Institute, The University of Manchester, Manchester, United Kingdom.
⁴ Department of Chemistry, Lancaster University, Lancaster, United Kingdom; Materials Science Institute, Lancaster University, Lancaster, United Kingdom.
⁵ Department of Materials and Henry Royce Institute, The University of Manchester, Manchester, United Kingdom; Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, Oslo, Norway. Electronic address: jonny.blaker@manchester.ac.uk.
⁶ Department of Materials and Henry Royce Institute, The University of Manchester, Manchester, United Kingdom. Electronic address: sarah.cartmell@manchester.ac.uk.

PMID: 36162344
DOI: 10.1016/j.bioadv.2022.213094

Abstract

Aligned sub-micron fibres are an outstanding surface for orienting and promoting neurite outgrowth; therefore, attractive features to include in peripheral nerve tissue scaffolds. A new generation of peripheral nerve tissue scaffolds is under development incorporating electroactive materials and electrical regimes as instructive cues in order to facilitate fully functional regeneration. Herein, electroactive fibres composed of silk fibroin (SF) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) were developed as a novel peripheral nerve tissue scaffold. Mats of SF with sub-micron fibre diameters of 190 ± 50 nm were fabricated by double layer electrospinning with thicknesses of ∼100 μm (∼70-80 μm random fibres and ∼20-30 μm aligned fibres). Electrospun SF mats were modified with interpenetrating polymer networks (IPN) of PEDOT:PSS in various ratios of PSS/EDOT (α) and the polymerisation was assessed by hard X-ray photoelectron spectroscopy (HAXPES). The mechanical properties of electrospun SF and IPNs mats were characterised in the wet state tensile and the electrical properties were examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The cytotoxicity and biocompatibility of the optimal IPNs (α = 2.3 and 3.3) mats were ascertained via the growth and neurite extension of mouse neuroblastoma x rat glioma hybrid cells (NG108-15) for 7 days. The longest neurite outgrowth of 300 μm was observed in the parallel direction of fibre alignment on laminin-coated electrospun SF and IPN (α = 2.3) mats which is the material with the lowest electron transfer resistance (R_et, ca. 330 Ω). These electrically conductive composites with aligned sub-micron fibres exhibit promise for axon guidance and also have the potential to be combined with electrical stimulation treatment as a further step for the effective regeneration of nerves.

Keywords: Electroactive biomaterials; Electrospinning; Interpenetrating polymer network; Peripheral nerve regeneration; Silk fibroin.

MeSH terms

Animals
Biocompatible Materials / pharmacology
Fibroins* / pharmacology
Laminin
Mice
Peripheral Nerves
Polymers / chemistry
Rats
Tissue Engineering / methods
Tissue Scaffolds / chemistry

Substances

Biocompatible Materials
Fibroins
Laminin
Polymers