Table 3.

Representative studies illustrating how nanofibers affect macrophage polarization

Fabrication methods and material features	Cells/Animals	M1 markers	M2 markers	Overall polarization	References
Electrospinning (PU-nanofibers: 270 nm diameter and 480 nm pore size. PU-microfibers: 1.15 μm diameter and 3.32 μm pore size)	RAW 264.7 Sprague Dawley rats and C57BL/6 mice	↑TNF-α, IL-1β and iNOS (microfibers)	↑CD206 and IL-10 (microfibers)	Nanofibers caused minimal macrophage responses and only mild foreign body reactions compared to microfibers	[91]
Electrospinning (3D PLGA nanofibrous meshes)	Human monocyte-derived macrophages	↑27E10, MACRO ↓IL-1β ↓TNF-α	↓CD163	M1 but with decreased expression of pro-inflammatory cytokines	[137]
Electrospinning (Aligned/random PLLA scaffolds, 550 nm and 1.6 μm)	RAW264.7	↓G-CSF ↓IFN-Ύ ↓TNF-α ↓RANTES, MIP-1α	N/A	M2-like	[139]
Electrospinning PDO scaffolds with different diameters and porosity)	C57BL/6 mice bone marrow derived macrophages and mouse endothelial cells	↓iNOS	↑TGF-β1 ↑Arg1	M2 (on larger fiber/pore sizes)	[140]