Adhesion assays of endothelial cells on nanopatterned surfaces within a microfluidic channel.
We present a simple analytical method to measure adhesion of human umbilical vein endothelial cells (HUVECs) and calf pulmonary artery endothelial cells (CPAEs) using nanopatterned, biodegradable poly(lactic-co-glycolic acid) (PLGA) surfaces for potential applications to artificial tissue-engineered blood vessel. Various nanostructured PLGA surfaces (350 nm wide ridges/350 nm grooves, 350 nm ridges/700 nm grooves, 350 nm ridges/1750 nm grooves, 700 nm ridges/350 nm grooves, 1050 nm ridges/350 nm grooves, 1750 nm ridges/350 nm grooves) and flat (unpatterned) surfaces were fabricated on the bottom of polydimethylsiloxane (PDMS) microfluidic channel of 2 mm width and 60 microm height by using thermal imprinting and irreversible channel bonding. To measure adhesion strength of HUVECs and CPAEs, the cells were exposed to a range of shear stress (12, 40, and 80 dyn/cm(2)) within the channels for 20 min after a preculture for 3 days and the remaining cells were counted under each condition. The highest adhesion strength was found on the surface of 700 nm wide ridges, 350 nm wide grooves for both cell types. The enhanced adhesion on nanopatterned surfaces can be attributed to two aspects: (i) contact guidance along the line direction and (ii) clustered focal adhesions. In particular, the contact guidance induced cell alignment along the line directions, which in turn lowers wall shear stress applied to the cell surface, as supported by a simple hydrodynamic model based on cell morphology.
Hwang
Se Yon
SY
School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, 151-742, Korea.
Kwon
Keon Woo
KW
Jang
Kyung-Jin
KJ
Park
Min Cheol
MC
Lee
Jeong Sang
JS
Suh
Kahp Y
KY
D002448:Cell Adhesion; D002478:Cells, Cultured; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D042783:Endothelial Cells / Q000166:cytology*; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D013499:Surface Properties
D004129:Dimethylpolysiloxanes; D005456:Fluorescent Dyes; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C013830:baysilon