Nanoporous Aluminium Oxide Membranes as Cell Interfaces

Table 1

Overview on the various cell types, which have been cultured on nanoporous AAO substrates with versatile geometries.

	Cell type	AAO nanopore geometry	Cell growth promoting coating	Reference
Neuronal cell cultures	Rat pheochromocytoma (PC12)	(i) Commercial AAO membranes (Anodisc, Whatman International Ltd) with pore diameters around 200 nm; (ii) Gold coating of 50 nm	Self-assembled monolayer cysteamine and poly-L-lysine	[35]
	Primary hippocampal neurons	Customised AAO membranes: (i) Pitch sizes from 60 to 450 nm; (ii) Pore depth varying from flat to nanoporous substrates	N-(2-aminoethyl)-3-aminopropyltrimethoxysilane	[36]
	Primary rat embryonic cortical neurons and locust thoracic ganglia neurons	Customised AAO nanopores: (i) Interpore distances of 20 to 300 nm; (ii) Porosity up to 40%	(i) Polylysine for rat neurons; (ii) Concanavalin A for insect neurons	[37]
	Mammalian neuronal cells (NG108-15)	Customised alumina nanopores on CMOS electrodes, produced with two-step anodisation: pitch sizes of 17 to 206 nm	N/A	[38, 39]
	Primary hippocampal neurons	Customised AAO membranes embedded in silicon: diameters from 25 to 100 nm	Poly-L-lysine	[40]
Connective tissue cell cultures	Human osteoblast-like cells (HOB)	Customised nanoporous AAO on titanium substrates: pore sizes from 160 to 200 nm	N/A	[13, 14]
		Commercial Anodisc membranes (Whatman) with 200 nm pore size	N/A	[41]
	Human osteosarcoma cell line (MG63)	Customised alumina nanopores on titanium sheets and commercial Anodiscs (Whatman): pore sizes ranging from 20 to 200 nm	Coating: N/A; Pores were partially filled with silica nanoparticles.	[42]
	Human fetal osteoblasts; (hFOB 1.19)	Customised AAO nanopores on aluminium sheets, produced by two-step anodisation: pore diameters between 75 and 89 nm. Anodiscs with 20 to 200 nm pores (Whatman) used as reference	N/A	[43, 44]
		Customised alumina nanopores on aluminium sheets, prepared in a two-step anodisation process: pore diameters of 30 to 80 nm	Vitronectin followed by arginine-glycine-aspartic acid-cysteine (RGDC)	[45]
		Primary bone marrow stromal cells (MSCs)	Customised AAO membranes, produced by two-step anodisation of aluminium sheets: 72 nm pore size	N/A	[46]
	NIH 3T3 fibroblasts	Customised AAO membranes with pore sizes ranging from 40 to 500 nm and commercial 200 nm Anodisc nanopores (Whatman)	N/A	[20]
		(i) Customised AAO nanopores with diameters from 75 to 300 nm.; (ii) A mask of PDMS holes was also deposited on the AAO membranes	N/A	[47]
		Murine 3T3 fibroblasts	(i) Commercial Anodisc membranes with 200 nm pores (Whatman) were coated with a polyethylene glycol hydrogel (PEG); (ii) Using photolithography microcompartments were produced in the PEG layer with sizes from 50×50 μm^2 to 200×200 μm^2 and 10 um high walls	Cell adhesive peptide Gly-Arg-Gly-Asp-Ser (GRGDS)	[48]
	IMR-90 lung fibroblasts	(i) Customised nanoporous AAO biocapsules with pores of 75 nm, prepared by two-step anodisation; (ii) PEG modification on the outer surface of the AAO capsule	N/A	[49]
Epithelial cells	Human embryonic kidney cells (HEK293)	Customised AAO nanopores; (i) Interpore distances of 20 to 300 nm; (ii) Porosity up to 40%	Extracellular matrix gel	[37]
	Human mammary epithelial cells (HMEC)	Customised AAO membranes, prepared in a two-step anodisation: (i) Pore diameter variation: 30, 40, 45, 50, and 80 nm; (ii) Variation of pore depth for a constant pore diameter of 80 nm: depths of 50, 90, 130, 180, 240, and 300 nm	N/A	[50]
	Human vascular endothelial cells from the umbilical cord (ECV304)	Customised AAO nanopores, prepared in a two-step anodisation: (i) Pore diameters of 50 and 200 nm; (ii) Pore depths of 500 and 2000 nm	N/A	[51]
	Human cervix carcinoma cell line (HeLa)	(i) Commercial AAO tissue culture inserts with pore sizes of 20 nm (Nunc, Thermo Fisher)	N/A	[52]
		(ii) AAO membrane was supported by a perforated PDMS film and placed between two electrodes to enable local electrical stimulation and solute delivery	Fibronectin	[53]
		Human KYSE-30 esophageal squamous epithelial cancer cells	(i) Customised AAO nanopores produced via two-step anodisation (25 to 75 nm); (ii) Structuring PEG coating via photolithography yielded circular microcompartments with diameters of 80 to 500 μm.	Fibronectin	[11, 54]
	HaCaT keratinocytes	Customised AAO membranes with pore sizes ranging from 40 to 500 nm and commercial 200 nm Anodisc membranes (Whatman)	N/A	[20]
	Human epidermal keratinocytes	(i) Commercial Anodisc membranes with 20 nm pores (Whatman); (ii) ALD coating with 8 nm Pt	1-Mercaptoundec-11-yl hexa(ethylene glycol) monolayers	[55]
		(i) Commercial Anodisc nanopores with 20 and 100 nm diameter (Whatman); (ii) ALD coating with 8 nm TiO2	N/A	[56]
		Hepatoma cell line HepG2	Customised nanoporous AAO membranes: (i) Self-supported AAO substrates with 40 and 270 nm diameter; (ii) Mechanically stabilized AAO membranes with 63 and 234 nm pore size	N/A	[34, 57–59]
	Primary mouse hepatocytes, cocultured with human adipose-derived mesenchymal stem cells (hASCs)	Customised, self-supported AAO membranes with pore sizes ranging from 50 to 60 nm	N/A	[60]
	Pancreatic cell line MIN6	Customised nanoporous AAO biocapsules with pore sizes between 46 and 75 nm, prepared by two-step anodisation	MIN6 cells were embedded into a collagen matrix inside the AAO capsule	[61]
	Human retinal endothelial cells (HREC)	Commercial alumina membrane cell culture inserts (Nunc, Fisher Scientific) with 20 nm pore size	N/A	[62]
Muscle cells	Mouse smooth muscle cells	Commercial nanoporous Anodisc membranes with 20 nm and 200 nm pore diameters (Whatman)	N/A	[63]
	Murine C2C12 myotubes	(i) Commercial nanoporous alumina membrane culture inserts with pores of 20 nm (Nunc, Thermo Fisher)	BD Matrigel^TM solution (BD Biosciences) containing ECM proteins	[64]
		(ii) AAO membrane was supported by a perforated PDMS film to create an electroporation device	Atelocollagen coating for muscle tissue-like stiffness	[65]
		Cardiomyocyte HL-1 cells	(i) Customised AAO nanopores with diameters below 50 nm; (ii) AAO nanopores as cell interface on gold microelectrode array	Fibronectin and gelatin	[66]
Blood cells	Neutrophils	Commercial nanoporous Anodisc alumina membranes (Whatman): pore diameters of 20 and 200 nm	No coating	[67]
			Protein coating (human serum, collagen type I, fibronectin, bovine serum albumin)	[68]
			Monocytes and macrophages	Commercial Anodisc nanopores (Whatman) with pore diameters of 20 and 200 nm	No coating	[69]
	Human platelet rich plasma	(i) Commercial nanopores with 20 nm diameter (Whatman); (ii) ALD coating with 8 nm Pt	1-Mercaptoundec-11-yl hexa(ethylene glycol) monolayers	[55]
	Whole blood	Commercial Anodisc nanopores (Whatman) with pore sizes of 20 and 200 nm	Blood collection materials were coated with heparin. AAO nanopores remained uncoated	[70–74]