Neuronal Electrophysiological Function and Control of Neurite Outgrowth on Electrospun Polymer Nanofibers Are Cell Type Dependent

Abstract

Modeling of cellular environments with nanofabricated biomaterial scaffolds has the potential to improve the growth and functional development of cultured cellular models, as well as assist in tissue engineering efforts. An understanding of how such substrates may alter cellular function is critical. Highly plastic central nervous system hippocampal cells and non-network forming peripheral nervous system dorsal root ganglion (DRG) cells from embryonic rats were cultured upon laminin-coated degradable polycaprolactone (PCL) and nondegradable polystyrene (PS) electrospun nanofibrous scaffolds with fiber diameters similar to those of neuronal processes. The two cell types displayed intrinsically different growth patterns on the nanofibrous scaffolds. Hippocampal neurites grew both parallel and perpendicular to the nanofibers, a property that would increase neurite-toneurite contacts and maximize potential synapse development, essential for extensive network formation in a highly plastic cell type. In contrast, non-network-forming DRG neurons grew neurites exclusively along fibers, recapitulating the simple direct unbranching pathway between sensory ending and synapse in the spinal cord that occurs in vivo. In addition, the two primary neuronal types showed different functional capacities under patch clamp testing. The substrate composition did not alter the neuronal functional development, supporting electrospun PCL and PS as candidate materials for controlled cellular environments in culture and electrospun PCL for directed neurite outgrowth in tissue engineering applications.

Tailor-Made Electrospun Culture Scaffolds Control Human Neural Progenitor Cell Behavior—Studies on Cellular Migration and Phenotypic Differentiation

“…In agreement with others using rodent cortical-and hippocampal-derived neural cells and the biodegradable and widely used biomaterials: PLGA, PCL and PLLA [8] [9] [10], the human cells used here displayed very good survival at the surfaces made of PLLA. Since we chose to use neurospheres as a seeding method it was not possible to quantify exact numbers of cells surviving the culture period.…”

“…expression of markers for late neuronal differentiation, such as MAP-2 and neurofilament as well as for synaptic formation (e.g., the markers synaptophysin and SV2 [29]. Studies of electrical activity are also needed, and Bourke at al previously reported maintained electrical activity over time in rodent CNS-derived neurons, using patch-clamp techniques [8].…”

“…Better cell survival, increased differentiation and facilitation of axonal outgrowth in vitro, were described using rodent embryonal cortical-, hippocampal-and retinal cells [8] [9] [10]. Neuronal differentiation from embryonic stem cells including human, was also promoted using fibrous substrates [11] [12].…”

β3-tripeptides act as sticky ends to self-assemble into a bioscaffold

“…Primary hippocampal neurons were isolated post-mortem from the brains of E18 Sprague Dawley rat fetuses, using established protocols. 35 Glass coverslips, with a diameter of 9 mm, were acid-washed, rinsed with 80% ethanol, allowed to dry, and then coated overnight with either PLO control or the self-assembled scaffolds to test their ability to promote neuron adhesion, survival, and function. Next morning, the coating was removed by Â3 washing in HBSS and kept moist until the cells became available (see below).…”

Patch method for culture of primary hippocampal neurons

“…In most of these studies, the primary neurons were cultured in culture dish or on glass slides with or without astrocytes [5]. It has been shown, however, that the neural growth and its functional performance are critically dependent on the culture conditions, especially the components and mechanical properties of the substrate [6,7], while the culture dish method is not sufficiently flexible to achieve the optimal conditions. In principle, mimicking the in vivo cell microenvironment can lead to significant improvement of the culture conditions [8,9].…”