Polyelectrolyte–Nanoparticle Hybrid Layers for Neural Cell Interaction

(1) Background: The development of a functional polyelectrolyte layer scaffold coating that promotes neural cell adhesion and growth is essential for improving the perfor-mance of neuro-regenerative materials interfaces. In this study, polyelectrolyte-based layer coatings modified with copper nanoparticles (CuNPs) and iron(II, III) oxide na-noparticles (Fe3O4NPs) were produced to enhance their physicochemical properties. (2) Methods: The effect of different concentrations of CuNPs and Fe3O4NPs incorporated within the coatings was verified in vitro on the neural stem cell line of mice, NE-4C, to assess the interaction in the material-cells interface. SEM was used to assess the mor-phology of cells immobilized within the nanocomposite material. Fluorescent evalua-tion and mitochondrial activity assays were performed to assess cell function immobi-lized on the material. (3) Results: Among others, the results of the mitochondrial activ-ity evaluation of NE-4C cells indicated that a higher share of Fe3O4NPs allows an in-crease in mitochondrial activity in neural cells in both PLL- and PEI-based materials. However, the involvement of a higher share (100 ppm) of CuNPs in a PLL-based ma-terial induced a decline in cell activity of up to 20% compared with a material not in-corporating nanoparticles. In the case of coating with CuNPs or Fe3O4NPs, the dependence of cell function on the proportion of Fe3O4NPs was observed. However, fluorescence observations confirmed the presence of both astrocytes and neurons on all selected scaffolds. The culture of the material containing Fe3O4NPs showed a greater proportion of neurons in the cell pop-ulation than the material containing CuNPs. (4) Conclusions: It was shown that the use of selected metallic nanoparticles affects both the morphology and function of neural cells. The obtained results suggest that nanoparticle incorporation can modu-late the interfacial environment that interacts with neural cells.