Effects of nanotopography on stem cell phenotypes

Table 3 Various cell types and the nanotopographies on which they are cultured

Cell type	Nanotopography	Advantages	Ref.
Chondrocytes	(a) PCL nanofibrous scaffold (200-800 nm) in the presence of TGF-β1; (b) Collagen nanofibers of diameter 110 nm-1.8 μm	The differentiation of the stem cells into chondrocytes in the nanofibrous scaffold was comparable to an established cell pellet culture. Nanotopography supports chondrocyte growth and infiltration	[82,90]
Osteoblasts	(a) Ceramics like HA, alumina and titania having nanostructures of grain sizes less than 100 nm and nanophase zinc oxide (23 nm); (b) PLGA, PLLA and PCL nanofibers (diameter 200-800 nm); (c) Nanotubes of diameter less than 100 nm	Enhanced proliferation and differentiation of MSC to osteoblasts	[67,77-79,105-113]
Smooth muscle cells (SMC)	(a) PLGA and PCL, PLLA-CL nanofibers (diameter 200-800 nm); (b) Nanogratings of 350 nm in width, spacing, and depth imprinted on PMMA or PDMS	SMC adhesion was enhanced on the nanostructured substrates compared to the conventional submicron substrates	[114-118]
Fibroblasts	(a) PLGA (85:15 ratio) nanofibers of diameter 500-800 nm; (b) Nanocolumns	Increased endocytic activity. Nanotopography can be used to improve hemocompatibility of blood-contacting biomaterials	[82]
Nerve cells	(a) Silicon wafer in the range of 20-70 nm; (b) PLLA or PCL scaffolds via electrospinning and phase separation	The cell adhesion and viability significantly improved on the nanofeatured surface	[70,91]

PCL: Polycaprolactone; TGF-β: Transforming growth factor-β; HA: Hydroxyapatite; PLGA: Poly-lactide-co-glycolide; PLLA: Poly-L-lactide acid; MSC: Mesenchymal stem cell; PMMA: Poly-methylmethacrylate; PDMS: Polydimethylsiloxane.