Abstract
Purpose: :
To study the epithelial cell response to nano–patterned extracellular matrix proteins developed using layer–by–layer lift–off (LbL–LO) technology.
Methods: :
Using LbL–LO nanofilm technology, test strips, approximately 4 x 8 mm in size, with tethered proteins (laminin and fibronectin) specifically patterned across the strip surface were developed. Glass coverslips were developed with three patterned strips containing one tethered protein on PDDA substrates The tested patterning on the left side of the slide was 50 µm squares separated by 80 µm horizontally and 250 µm vertically, the center strip was 20µ m squares separated by 60 µm both horizontally and vertically, and the right strip was 50 µm squares separated by 60 µm horizontally and 250 µm vertically. The "islands" patterned within each strip were developed using 15.38 µg/ml of fibronectin–PEG–BTCA and 7.69µ g/ml of laminin–PEG–BTCA in DI H2O at pH 5. Cellular response to the test strips was determined using rabbit epithelial cell culture.
Results: :
AFM images confirmed coverslip patterning. Islands within a fibronectin–PEG–BTCA patterned rectangle showed average heights of 6.84 ± 1.45 nm. The non–BTCA protein control surfaces (deposited on positive polymer–coated surfaces above their isoelectric point) showed no patterning but a rather diffuse coating. The nanofilms were then put into epithelial cell culture, where by day 3 the laminin–PEG BTCA nanofilms had confluent cells covering the left–side pattern, whereas the fibronectin–PEG–BTCA nanofilms had only 30% coverage over the same pattern.
Conclusions: :
Our results validate the use of LbL–LO methodology for screening multiple types of nanopatterned surfaces as to their cellular response in a reproducible and relatively easy manner.
Keywords: cornea: epithelium • proliferation • extracellular matrix