Table 3.

Referenced studies on interfacing composites with NS/PCs and NS/PC-like cells.

Reference	Material	Cell	Applied ES	Key Findings
Cuttaz et al. 2019[351]	PU-PEDOT:PSS films	ReNcell-VM human NPCs	N/A	Composites over a range of PEDOT:PSS concentrations supported cell viability and promoted varying levels of neuronal and glial differentiation and neurite elongation.
Fu et al. 2019[40]	PLGA-graphene oxide films	Mouse cortical NSCs (E14)	100 mV for 1 h per day	Alone, the substrate demonstrated good cytocompatibility. Applied stimulation increased cell proliferation, neuronal differentiation, and neurite extension.
Ginestra et al. 2019[361]	Electrospun fibers of PCL and graphene nanoparticles	Mouse NSCs (E12)	N/A	The addition of 2% graphene nanoparticles to PCL fibers enhanced cell differentiation towards dopaminergic neurons.
Javadi et al. 2018[395]	Hydrogel composite of PU, PEDOT:PSS, and liquid crystal graphene oxide	ReN-CX human NSCs	+/−0.25 mA cm−2 biphasic waveform of 100 μs with 20 μs interphase at 250 Hz	Stimulation applied to NSCs seeded on composite hydrogels increased neurite count and average length.
L. Wang et al. 2019[355]	PLGA nanofibrous mat coated with graphene oxide	Mouse cortex NPCs (E14)	N/A	High cell viability and growth was supported below 0.5 wt% graphene oxide. NPCs preferably differentiated into astrocytes. Methylene blue adsorption to fibers enabled controlled release.
Luo et al. 2021[394]	Gelatin hydrogels with infused PPy-conjugated chondroitin sulfate	Mouse hippocampal NS/PCs (E14)	N/A	Cultured NS/PCs differentiated into either mature neurons or astrocytes. When implanted in rats with spinal cord injury, the hydrogel with 3 wt% PPy-chondroitin sulfate promoted improved hindlimb functional recovery better than groups with 1 wt%.
Wang et al. 2018[397]	Chitosan/Gelatin 3D scaffold with deposited PEDOT	Rat hippocampal NSCs (E13-E15)	N/A	Cell proliferation increased when cultured with mitogens and PEDOT was added to the scaffold. Exposure to differentiation medium led to increased glial and neuronal differentiation on scaffolds with PEDOT.
Shin et al. 2017[392]	Hyaluronic Acid Hydrogels with CNT or PPy	Human fetal NSCs and human iPSC-derived NPCs	N/A	The incorporation of PPy into the hydrogel generally increased neuronal and decreased astrocyte differentiation, while CNT increased oligodendrocyte differentiation.
Yang et al. 2018[371]	3D scaffold formed by laminin-annealed MnO2 sheets	Human iPSC (WT126 clone 8; WT33 clone 1)-derived NPCs	N/A	Neuronal differentiation on the scaffold was enhanced with controlled release of a small molecule Wnt inhibitor. Implanting NSC-seeded scaffolds in a mouse hemisection model of SCI reduced subacute inflammation when compared to controls.