Controlling cell adhesion on human tissue by soft lithography

Soft lithographic techniques are widely used for fundamental biological applications. This study investigates the extension of soft lithography for use on human tissue to create a biological implant by systematically studying the effect of pattern size on cellular morphology. We focus on mimicking a key layer of the physiological retina with an organized monolayer of epithelial cells to act as a new treatment for age-related macular degeneration. We show that epithelial cells can be confined to cytophilic islands defined on lens capsule by the inhibitory polymer poly(vinyl alcohol). In addition, as the size of the cytophilic islands grows, both the fraction of islands with cells attached and the number of cells adhered to each island increase. High densities of cell adhesion and single cell attachment per island were achieved with a 25 mum pattern size. Over time, the cells spread over the 5 mum wide barriers to form a confluent monolayer that may eventually serve as a functional retinal implant. With the ability to apply soft lithography to tissue samples, human tissue may become a universal membrane substrate for other ocular diseases or in tissue engineering applications elsewhere in the body.