Mammalian cell cultures on micropatterned surfaces of weak-acid, polyelectrolyte hyperbranched thin films on gold.

A four-step soft lithographic process based on micro-contact printing of organic monolayers, hyperbranched polymer grafting, and subsequent polymer functionalization results in polymer/n-alkanethiol patterns that direct the growth and migration of mammalian cells. The functional units on these surfaces are three-dimensional cell "corrals" that have walls 52+/-2 nm in height and lateral dimensions on the order of 60 microm. The corrals have hydrophobic, methyl-terminated n-alkanethiol bottoms, which promote cell adhesion, and walls consisting of hydrophilic poly(acrylic acid)/poly(ethylene glycol) layered nanocomposites that inhibit cell growth. Cell viability studies indicate that cells remain viable on the patterned surfaces for up to 21 days, and fluorescence microscopy studies of stained cells demonstrate that cell growth and spreading does not occur outside of the corral boundaries. This simple, chemically flexible micropatterning method provides spatial control over growth of IC-21 murine peritoneal macrophages, human umbilical vein endothelial cells, and murine hepatocytes.