(686b) Nanometer-Scale Cell Adhesive Domains for the Control of Cell-Material Interactions

Interferometric lithography is a fast and easy method that uses the interference of two coherent optical beams to produce a standing wave that can be recorded in a photoresist. In our work, wafers were coated with a positive photoresist, exposed, and washed creating grooves of photoresist. Substrates were then rotated 90° and exposed again creating pillars. Samples were then coated with gold and the pillars removed, revealing uncoated patches throughout the gold-coated surface. Self-assembled monolayers of poly(ethylene glycol) (PEG)-terminated thiols were formed on the gold coated surfaces to create non-cell adhesive areas. On the nanometer-scale patches, fibronectin was adsorbed, rendering them cell adhesive. The substrates were visualized with SEM after incubation with gold-labeled anti-fibronectin antibodies. Substrates with domain pitches 100, 200, and 400 nm were fabricated, characterized, and used in cell attachment and spreading studies. After sterilization, the substrates were seeded with the MC3T3-E1 cells. After 12 hours I culture, 92±1% and 84±1% of the seeded cells attached and were viable on the substrates with pitches of 350 and 450 nm, respectively, compared to 94±4% on glass positive controls. These results indicate that we were able to fabricate surfaces with discrete nanometer scale cell adhesive patches to which cells attached. The ability to precisely control cell attachment and spreading may be important for regulating cellular function for many diverse biomedical applications.