Electroconductive polymeric nanowire templates facilitates in vitro C17.2 neural stem cell line adhesion, proliferation and differentiation

Abstract

Stem cells still remain one of the most exciting and lucrative options for treatment of variety of nervous system disorders and diseases. Although there are neural stem cells present in adults, the ability of both the peripheral and central nervous system for self-repair is limited at best. As such, there is a great need for a tissue engineering approach to solve nervous system disorders and diseases. In this study, we have developed electrically conductive surfaces with controlled arrays of high aspect ratio nanowires for the growth and maintenance of neural stem cells. The nanowire surfaces were fabricated from polycaprolactone using a novelnanotemplating technique, and were coated with an electrically conductive polymer, polypyrrole. The polypyrrole coated nanowire surfaces were characterized using scanning electron microscopy and X-ray photoelectron spectroscopy. Additionally, the surface resistance of polypyrrole coated nanowire surfaces was measured. C17.2 neural stem cells were used to evaluate the efficacy of the polypyrrole coated nanowire surfaces to promote cell adhesion, proliferation, and differentiation. The results presented here indicate significantly higher cellular adhesion and proliferation on polypyrrole coated nanowire surfaces as compared to control surfaces. The differentiation potential of polypyrrole nanowire surfaces was also evaluated by immunostaining key neuronal markers that are expressed when NSCs differentiate into their respective neural lineages.

Neural Stem/Progenitor Cell Clones as Models for Neural Development and Transplantation

“…Nanofibrous scaffolds fabricated with different ratios of poly(epsilon-caprolactone) (PCL) and gelatin were tested in their ability to promote neuronal differentiation of C17.2 cells, and the PCL/gelatin 70:30 ratio generated the best biomaterial suited for nerve regeneration (Ghasemi-Mobarakeh et al, 2008). Similar cell culture tests were also performed on electroconductive polymeric nanowire templates showing that polypyrrole coating improved their effects on cell adhesion and proliferation (Bechara et al, 2011).…”

Conductive interpenetrating networks of polypyrrole and polycaprolactone encourage electrophysiological development of cardiac cells

“…PCL is a biodegradable polyester that has been FDA-approved for use clinically in drug delivery devices and as a component of biomaterials used for bone regeneration [30]. Interpenetrating networks of PPy and PCL have demonstrated physiological levels of conductivity [15], and copolymers of PPy and PCL have been shown to enhance neurite outgrowth from rat PC12 cells [24], which, like cardiomyocytes, respond to electrical stimuli. The conductivity of the PPy-PCL creates an environment conducive to electrical stimulation, thereby mimicking conditions found in the heart.…”

“…Multiple avenues for creating conductive substrates for cell growth have been explored, including the use of carbon nanotubes [10][11][12], use of homogenously dispersed gold particles [13], and entirely polymer-based scaffolds incorporating electrically-conductive polymers such as polypyrrole (PPy) [14,15]. The cost of gold nanoparticles may prohibit their large-scale application as electroactive biomaterials, whereas the potential cytotoxicity of carbon nanotubes may limit their use within biodegradable implantable scaffolds [16].…”

“…The cost of gold nanoparticles may prohibit their large-scale application as electroactive biomaterials, whereas the potential cytotoxicity of carbon nanotubes may limit their use within biodegradable implantable scaffolds [16]. PPy has been used widely as an electrically conductive polymer for neural tissue engineering applications [15,17]. The selection of the dopant counterions during the synthesis of electroactive polymers has an effect on the biocompatibility of the electroactive polymer (PPy) in vitro, with high molecular weight dopants (typically polyanions such as polystyrene sulfonate) being attractive because they will not readily leach from the polyelectrolyte complex formed with the (typically) polycationic PPy [18][19][20][21].…”

Gold nanowires to mend a heart

“…For instance, such composite biomaterials may be used to engineer a multitude of other types of tissues, including neuronal and bone, or to improve the surface electrical properties and biocompatibility of many materials, such as implants. Moreover, these materials may also direct stem cell differentiation 6 .…”