Polylactic Acid/Polyaniline Nanofibers Subjected to Pre- and Post-Electrospinning Plasma Treatments for Refined Scaffold-Based Nerve Tissue Engineering Applications

Abstract

Composite biopolymer/conducting polymer scaffolds, such as polylactic acid (PLA)/ polyaniline (PAni) nanofibers, have emerged as popular alternative scaffolds in the electrical-sensitive nerve tissue engineering (TE). Although mimicking the extracellular matrix geometry, such scaffolds are highly hydrophobic and usually present an inhomogeneous morphology with massive beads that impede nerve cell-material interactions. Therefore, the present study launches an exclusive combinatorial strategy merging successive pre- and post-electrospinning plasma treatments to cope with these issues. Firstly, an atmospheric pressure plasma jet (APPJ) treatment was applied on PLA and PLA/PAni solutions prior to electrospinning, enhancing their viscosity and conductivity. These liquid property changes largely eliminated the beaded structures on the nanofibers, leading to uniform and nicely elongated fibers having average diameters between 170 and 230 nm. After electrospinning, the conceived scaffolds were subjected to a N2 dielectric barrier discharge (DBD) treatment, which significantly increased their surface wettability as illustrated by large decreases in water contact angles for values above 125° to values below 25°. X-ray photoelectron spectroscopy (XPS) analyses revealed that 3.3% of nitrogen was implanted on the nanofibers surface in the form of C–N and N–C=O functionalities upon DBD treatment. Finally, after seeding pheochromocytoma (PC-12) cells on the scaffolds, a greatly enhanced cell adhesion and a more dispersive cell distribution were detected on the DBD-treated samples. Interestingly, when the APPJ treatment was additionally performed, the extension of a high number of long neurites was spotted leading to the formation of a neuronal network between PC-12 cell clusters. In addition, the presence of conducting PAni in the scaffolds further promoted the behavior of PC-12 cells as illustrated by more than a 40% increase in the neurite density without any external electrical stimulation. As such, this work presents a new strategy combining different plasma-assisted biofabrication techniques of conducting nanofibers to create promising scaffolds for electrical-sensitive TE applications.

Aligned polycaprolactone/polyaniline electrospun nanofibers for directing neural stem cell differentiation and neuron arrangement

“…Indeed, electrical activity is a distinguishing feature of nervous tissue that can be exploited to guide tissue regeneration and enhance the biomimicry of tissue graft and in vitro models (Bierman-Duquette et al, 2022). Conductive polymers, such as poly (pyrrole) and PANI, have been used to confer electrical activity to nervous tissue-engineered scaffolds (Farkhondehnia et al, 2018;Garrudo et al, 2019;Guo et al, 2023) thereby promoting neural cell differentiation and the formation of longer neurites (Jin and Li, 2015). In particular, PANI is widely selected for the preparation of electrospun scaffolds (Razak et al, 2015;Garrudo et al, 2019).…”

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“…Indeed, electrical activity is a distinguishing feature of nervous tissue that can be exploited to guide tissue regeneration and enhance the biomimicry of tissue graft and in vitro models (Bierman-Duquette et al, 2022). Conductive polymers, such as poly (pyrrole) and PANI, have been used to confer electrical activity to nervous tissue-engineered scaffolds (Farkhondehnia et al, 2018;Garrudo et al, 2019;Guo et al, 2023) thereby promoting neural cell differentiation and the formation of longer neurites (Jin and Li, 2015). In particular, PANI is widely selected for the preparation of electrospun scaffolds (Razak et al, 2015;Garrudo et al, 2019).…”