UV-based patterning of polymeric substrates for cell culture applications

We studied the physico/chemical effects of deep UV irradiation of polystyrene, polymethylmethacrylate and polycarbonate with respect to cell adhesion in vitro. Photochemical modifications of the polymer surfaces yielded active peroxide compounds which allowed graft coupling of acrylic monomers (acrylamide, acrylic acid) together with oxidized chemical groups which were identified by X-ray photoelectron spectroscopy, dye binding and contact angle titrations as being mainly carboxylic groups. It was observed that hepatocytes (HepG2, human hepatoma cell line) and fibroblasts (1,929, murine cell line) exhibit strong adhesion on the irradiated polymer surfaces. Masked irradiations opened a simple, fast, and economical route to obtain chemically patterned polymeric substrates for structured cell adhesion. This is more advantageous as compared to silane based patterning techniques on glass or thiol based patterning on gold due to the elimination of any chemical treatment, the clean room compatibility and the small size of achieved structures. The described cell patterning technique may become a useful tool for the study of a variety of defined co-cultures (for example hepatocytes and fibroblasts), neuronal networks, intercellular communication, organogenesis and for applications like biosensors or engineered highly functional tissues and implants as bioartificial organs.