Fig. 6

A Assembly of magnetic nanochains and guided oriented growth of the neurons (a). Fe₃O₄@SiO₂ nanoparticles, single magnetic nanochain, and overview of magnetic nanochains observed by SEM (b). Representative fluorescent photographs of cells migration in groups (green: nestin; blue: DAPI), and orientation angle plots (c). Representative fluorescent photographs of directional growth of neurons in groups and Orientation angle plots (d). Reprinted with permission from ref. [116]. B Schematic diagram of NGF-gradient/aligned PCL conduits fabrication by electrospinning, and NH2-Heparin-NGF group gradient was formed by the dynamic reaction of ethylenediamine solution on PCL (a). Nerve cell neurite outgrowth and orientation on fiber morphology of R-PCL and A-PCL conduits (b). Average neurite length in two directions (c). Number of myelinated axons and sciatic functional index in conduit utilization (d). Reprinted with permission from ref [121]. (C) SEM images of micropatterned PLCL films after being aminolyzed for 2, 4 and 8 min (a). Scheme to show the five parts of gradient in micropatterned gradient PLCL and the peptide density on the surface of micropatterns (b). Migration traces of nerve cells (c), immunofluorescence staining images of CD163 (green), CD86 (red), and DAPI (blue) for M2, M1 and cell nuclei in regenerated nerves (d), optical images of regenerated nerves in vivo (e) and TEM images of nerves guided (f) by Flat, FG, MU, and MG conduits, and autografts, respectively. Reprinted with permission from ref [122]. D SEM images of PC12 cells on aligned PPy-PLLA fibers without and with electrostimulation of 200 mV/cm, and inset fluorescent images of PC12 cells with two growth cones (a). Fluorescence images of PC12 with electrostimulation of 100, 200, and 400, mV/cm, respectively (b). Median length of neurites from PC12 with under different electrostimulations (c). Reprinted with permission from ref [24]