The Influence of the Surface Topographical Cues of Biomaterials on Nerve Cells in Peripheral Nerve Regeneration: A Review

Table 3

Summary of the effects of sizes on cell alignment and neurite guidance.

	Diameter	Material	Cell type	Effects on cell behaviors	Reference
Silk nanofibers/scaffold		Silk fibroin	Human embryonic stem cell- (hESC-) derived neural precursors (NPs)	Cell viability, neuronal differentiation, and neurite outgrowth are greater on aligned 400 nm fibers	[83]
Poly (L-lactic acid) (PLLA) nano/microfibrous scaffolds	300 nm (nanometer scale); 1.5 mm (submicron scale)	PLLA	Neural stem cells (NSCs)	Aligned nanofibers highly supported the NSC culture and improved the neurite outgrowth	[86]
Silk fibroin (SF)	400 nm; 1200 nm	Silk fibroin (SF)	Astrocytes	Significant increase in astrocyte diffusion area on SF scaffolds at 400 nm	[89]
Poly-L-lactic acid (PLLA) fibers		Poly-L-lactic acid (PLLA) fibers	DRG neurites in chicks	Large fiber diameters () obviously promote the directional growth and extension of neurites	[88]
Gradients	Wavelengths ranging from 1.5 μm to 3.8 μm and amplitudes ranging from 176 nm to 780 nm	Polydimethylsiloxane (PDMS)	Human pulmonary microvascular endothelial cells (ECs)	Caused formation of early networks that can be stabilized by the use of the guidance layer of adipogenic stromal cells (ASC)	[94]
	Wavelengths ranging from 4.8 to 9.9 μm and amplitudes ranging from 1015 to 2169 nm			Caused cell alignment and inhibited vascular endothelial network formation
Electrospun scaffolds	100 nm and 300 nm; 1200 nm	Poly(ε-caprolactone) (PCL) and type I collagen	Endothelial cell (EC)	Significantly larger aspect ratio and long axis length	[95]