Production of Blended Poly(acrylonitrile): Poly(ethylenedioxythiophene):Poly(styrene sulfonate) Electrospun Fibers for Neural Applications

Abstract

This study describes, for the first time, the successful incorporation of poly(ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) in Poly(acrylonitrile) (PAN) fibers. While electroconductive PEDOT:PSS is extremely challenging to electrospun into fibers. Therefore, PAN, a polymer easy to electrospun, was chosen as a carrier due to its biocompatibility and tunable chemical stability when cross-linked, particularly using strong acids. PAN:PEDOT:PSS blends, prepared from PEDOT:PSS Clevios PH1000, were electrospun into fibers (PH1000) with a diameter of 515 ± 120 nm, which after being thermally annealed (PH1000 24H) and treated with heated sulfuric acid (PH1000 H2SO4), resulted in fibers with diameters of 437 ± 109 and 940 ± 210 nm, respectively. The fibers obtained over the stepwise process were characterized through infra-red/Raman spectroscopy and cyclic voltammetry. The final fiber meshes showed enhanced electroconductivity (3.2 × 10−3 S cm−1, four-points-assay). Fiber meshes biocompatibility was evaluated using fibroblasts and neural stem cells (NSCs) following, respectively, the ISO10993 guidelines and standard adhesion/proliferation assay. NSCs cultured on PH1000 H2SO4 fibers presented normal morphology and high proliferation rates (0.37 day−1 vs. 0.16 day−1 for culture plate), indicating high biocompatibility for NSCs. Still, the low initial NSC adhesion of 7% calls for improving seeding methodologies. PAN:PEDOT:PSS fibers, here successful produced for the first time, have potential applications in neural tissue engineering and soft electronics.

Novel Electroactive Mineralized Polyacrylonitrile/PEDOT:PSS Electrospun Nanofibers for Bone Repair Applications

“…Similar results were reported by Laforgue et al ( 2016) and Hosseini et al ( 2020) with sulfuric acid-doped PEDOT:PSS films [36,65]. Overall, the shifts in the FTIR spectra of the HAT-PAN and HAT-PAN/PEDOT:PSS nanofibers appear to be in line with those observed by our group on the same set of scaffolds with Raman spectroscopy [40].…”

“…On the other hand, two new stabilized PAN-related IR peaks could be identified in the FTIR spectra of both HAT-PAN and HAT-PAN/PEDOT:PSS scaffolds, thus confirming the presence of a modified polymer as opposed to pristine PAN: 805 cm −1 (-C=C-H-bending vibration, heptazine rings) and 1582 cm −1 (C=N, C=C, N-H mixed stretching) [63]. This appears to be in agreement with the published literature, where similar changes in the structure of PAN after annealing are described [40,47,63,64]. The HAT treatment did not have any noticeable negative impact on the wettability of the scaffolds (Supplementary Material, Figure S1).…”

“…2.1. Production and Physicochemical Characterization of PAN/PEDOT:PSS Nanofibers before Post-Processing PAN and PAN/PEDOT:PSS nanofibers were successfully produced by electrospinning using previously optimized operational parameters [40]. Scanning electron microscopy (SEM) and Energy Dispersive X-ray (EDX) analyses of the scaffolds were conducted to assess fiber morphology and composition, respectively (Figure 1).…”

“…In this study, we describe the fabrication of novel PEDOT:PSS nanofibers via electrospinning capable of mimicking key features of the bone's ECM and providing a platform for the application of exogenous ES. The scaffolds were prepared by blending the CP with non-conductive polyacrylonitrile (PAN), used as a carrier polymer, adapting a novel protocol previously described by Garrudo et al (2023) [40]. The resulting constructs were annealed and dipped in sulfuric acid in order to enhance the electroconductivity of the nanofibers.…”

Synergy between 3D-extruded electroconductive scaffolds and electrical stimulation to improve bone tissue engineering strategies

“…31–33 Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is an ECP, suitable for the design of TE scaffolds due to its high stability and biocompatibility. 34–36 For example, Guex and colleagues 37 reported the development of an electroconductive (6.1 × 10 −6 S cm −1 ) ice-templated PEDOT:PSS scaffold capable of supporting MC3T3-E1 cells' osteogenic differentiation and the deposition of the mineralized extracellular matrix (ECM). PEDOT:PSS can also be processed into versatile electroconductive composites with collagen 38 and nanohydroxyapatite/chitosan 39 for bone TE applications.…”