Table 3.

Summary of ultrathin membranes that can be utilized in tissue barrier and co-culture models. Pnc-Si (Porous Nanocrystalline Silicon), SiN (Silicon nitride), SiO₂ (silicon dioxide)

Material	Commercially available?	Attributes	Cell or tissue type	Goal of the study
Parylene	No – Lithography	0.8 – 4.0 μm pores, 1 μm thick	Fibroblast co- culture	Fabrication of thin membranes allowing physical contact52
Pnc-Si	No – Rapid phase transition and lithography	15 nm thick, 3 – 80 nm “pores”	Endothelium	Investigate feasibility of nanomembrane-supported endothelial barrier model30
Pnc-Si	No – Rapid phase transition and lithography	15 – 30 nm thick (likely), 30 – 80 nm pores (likely)	Endothelium	On chip TEER measurement correction113
Pnc-Si and SiN	No – rapid phase transition and lithography	15 nm thick, 30 nm pores, supported on a SiN hexagonal grid	Neutrophils	Shear-free chemotaxis and cell labeling21
SiN	No – Lithography	0.27 – 0.7 μm pores, 1 μm thick	Blood brain barrier	Allowance of physical contact to improve tissue barrier51
SiN	No – rapid phase transition and lithography	0.3 μm thick, 40 – 80 nm pores	Endothelium	Demonstration of cell culture114
SiO2	No – Lithography	0.3 μm thick, 0.5 – 3.0 μm pores	HUVEC/ADSC co- culture	Fabrication of ultrathin membranes for cell culture32
SiO2	No – Lithography	0.3 μm thick, 0.5 and 3.0 μm pores	Endothelium	Cell-substrate interactions49
SiO2	No – Lithography	0.3 μm thick, 0.5 and 3.0 μm pores	Vasculature	Endothelial differentiation of ADSC and perivascular interaction55