Nanopatterning effects on astrocyte reactivity

Abstract

An array of design strategies have been targeted toward minimizing failure of implanted microelectrodes by minimizing the chronic glial scar around the microelectrode under chronic conditions. Current approaches toward inhibiting the initiation of glial scarring range from altering the geometry, roughness, size, shape, and materials of the device. Studies have shown materials which mimic the nanotopography of the natural environment in vivo will consequently result in an improved biocompatible response. Nanofabrication of electrode arrays is being pursued in the field of neuronal electrophysiology to increase sampling capabilities. Literature shows a gap in research of nanotopography influence in the reduction of astrogliosis. The aim of this study was to determine optimal feature sizes for neural electrode fabrication, which was defined as eliciting a nonreactive astrocytic response. Nanopatterned surfaces were fabricated with nanoimprint lithography on poly(methyl methacrylate) surfaces. The rate of protein adsorption, quantity of protein adsorption, cell alignment, morphology, adhesion, proliferation, viability, and gene expression was compared between nanopatterned surfaces of different dimensions and non-nanopatterned control surfaces. Results of this study revealed that 3600 nanopatterned surfaces elicited less of a response when compared with the other patterned and non-nanopatterned surfaces. The surface instigated cell alignment along the nanopattern, less protein adsorption, less cell adhesion, proliferation and viability, inhibition of glial fibrillary acidic protein, and mitogen-activated protein kinase kinase 1 compared with all other substrates tested.

Enhanced GLT-1 mediated glutamate uptake and migration of primary astrocytes directed by fibronectin-coated electrospun poly-l-lactic acid fibers

“…Prepared films and fiber scaffolds were then plasma treated for 90 seconds using a Plasma Cleaner (Harrick Plasma, Ithaca, NY). Components within the extracellular matrix (ECM) are known to regulate astrocyte behavior [41–42]. In order to determine the best ECM coating for the PLLA fibers that promoted robust astrocyte adhesion, astrocytes were seeded on aligned PLLA fibers that were coated overnight with fibronectin (Sigma-Aldrich), laminin (Invitrogen), or collagen I (Invitrogen) at a concentration of 10 µg/mL.…”

Nanoscaffold's stiffness affects primary cortical cell network formation

“…1 Properties such as the stiffness and topography of the scaffold material have a significant effect on the number of primary neurons and astrocytes attached, as well as on the direction of their outgrowths. [2][3][4] Researchers have been working on micro-or nanopatterned substrates to guide neuronal outgrowth, to help study the neural electrical signal transmission in single neurons, 5 and to aid nerve regeneration processes. 6 Therefore, our goal is to combine microfluidics with tissue engineering to create a "living brain," generating realistic in vitro neural circuitry, which can be used to standardize experimental neuronal cell culture.…”

Astrocytes alignment and reactivity on collagen hydrogels patterned with ECM proteins

“…Based on the previous reports that the introduction of FBG into the CNS after injury triggers CSPG production [46], and that fact that AGG already contains inhibitory CS chains, it appears that the alignment itself was the dominant contributing factor resulting in the decrease in CSPG expression seen here (Fig 5). It has been shown that the presence of topographical cues that aligned astrocytes also reduced astrocyte reactivity [47]. Similarly, astrocytes grown on aligned electrospun fibers of polycaprolactone had decreased GFAP expression compared to those on random fibers [48].…”