Influence of Poly(L-Lactic Acid) Aligned Nanofibers on PC12 Differentiation

Abstract

The aim of this study was to unveil the mechanism by which aligned nanofibers influence neuronal differentiation. PC12 cells were seeded on three different poly(L-lactic acid) (PLLA) substrates (PLLA films (control), electrospun PLLA random nanofibers (RF) and electrospun PLLA aligned nanofibers (AF)). Subsequently, cellular experiments, cDNA microarrays and molecular biological approaches were employed to investigate the impacts of the different PLLA substrates on PC12 cell differentiation. Scanning electron microscope observation revealed that neurite outgrowth in the AF group was parallel to the direction of nanofiber alignment and that the filopodias at the neurite tips spread along the aligned nanofiber axis. Meanwhile, both neurite length and the expression of GAP43 (a neuronal differentiation marker gene) were higher in the AF group than those in the control and RF groups. These results suggested that the PLLA aligned nanofibers enhanced PC12 cell differentiation. cDNA microarray experiment revealed that 876 and 1937 genes had significantly changed expression in the RF and AF groups, respectively. Based on gene ontology analysis, 493 and 1193 differentially expressed genes involved in neuronal differentiation were found in the RF and AF groups, respectively. Pathway analysis showed that the PLLA aligned nanofibers mainly mediated their effects via integrin-mediated pathways. qRT-PCR and western blotting assays further confirmed that gene and protein expression levels in the integrin-mediated FAK-MEK-ERK pathway (e.g., Tln1, Mapk6, phosphorylated-ERK1/2) were enhanced by the PLLA aligned nanofibers. Both PC12 cell differentiation and the expressions of genes and proteins in the integrin-mediated FAK-MEK-ERK pathway were inhibited when integrins were blocked by the pentapeptide GRGDS. In addition, the Pafah1b-1 gene was found to be involved in PLLA aligned nanofibers' promotion of PC12 cell differentiation. Taken together, the results suggested that PLLA aligned nanofibers might cooperate with nerve growth factor (NGF) to induce PC12 cell differentiation by activating the integrin-mediated FAK-MEK-ERK pathway and the Pafah1b1 gene.

Gold nano‐decorated aligned polyurethane nanofibers for enhancement of neurite outgrowth and elongation

“…So, aligned nanofibers are one of the important surfaces as they provide aligned topography that the best suit to axonal guidance . Also, many studies have mentioned that aligned nanofibers could promote neural stem cell differentiation, especially when coupled with nerve growth factor (NGF) …”

“…7 Also, many studies have mentioned that aligned nanofibers could promote neural stem cell differentiation, especially when coupled with nerve growth factor (NGF). [8][9][10][11] As it is known neurons are electrically active cells which their electrical activity originates from the opening and closing of specific ion-channel proteins in the plasma membrane and help them to conduct, transmit, and receive electric signals. So using conductive electroactive biomaterials with the ability to support this phenomenon is very important in nerve tissue engineering.…”

Hierarchically Assembled Nanofibers Created by a Layer-by-Layer Self-Assembly

“…fiber diameter, porosity, and the newer area of micro-to macro-scale patterns, electrospun materials exhibit various other fascinating morphologies, such as helical, ribbonlike, beads-on-a-string, multi-channel tubular, porous honeycomb, nanoporous, nanopillared, core-shell and hollow structures, many of which are also observed in nature. [14][15][16] Control over the surface properties of ultrathin films, such as wettability and adsorption behavior, are important in a wide variety of applications, including surface selfcleaning, antiadhesives, biosensing, and separations. 17 The Layer-by-Layer (LbL) self-assembly technique presents a great advantage over many other coating techniques in that it is possible to control and finely tune the thickness and structure of the coating on a nanometer scale, simply by adjusting factors such as the ionic strength, pH and the number of dipping cycles.…”

The Interactions Between Aligned Poly(L-Lactic Acid) Nanofibers and SH-SY5Y Cells In Vitro

“…19 Our previous study found that aligned nanofibers could promote PC12 cell differentiation via p-ERK1/2 mediated signal pathway. 20 Some other studies also showed that integrins can trigger p-ERK1/2 to further affect more gene transcription. 21 We implied that integrins may also fulfill their functions by inducing the expression of p-ERK1/2 in the aligned PLLA nanofibers-SH-SY5Y cells interaction.…”