Photo-patterned oxygen sensing films based on Pt porphyrin for controlling cell growth and studying metabolism.

A new type of biocompatible and photo-polymerizable hydrogel with oxygen sensors for microengineering was developed. Herein, a red emitter as an oxygen probe which was chemically immobilized in a poly(2-hydroxyethyl methacrylate)--polyacrylamide-based matrix was expected to monitor cell metabolism. A few micropatterned films with gratings (5, 7, 10, 20, and 50 μm in width, respectively and with 1.2 μm in height) were designed and fabricated by photo-lithography using these hydrogels. SEM and AFM were used to validate these films to attain their lateral width and vertical depth. The oxygen responses of these films were characterized. Results showed that patterned films exhibited higher sensitivity than the non-patterned films. The films' construction can also have some influence on cell alignment and elongation. This phenomenon was evaluated by culturing human cervical cancer cells (HeLa cells) and mouse embryo fibroblasts (3T3-L1), on the film surfaces with different construction. Linear correlation between cell elongation and the logarithm of grating width was observed. Real-time monitoring of oxygen consumption of HeLa cells in cell culture medium was achieved. This study is expected to have potential to be applied in micro-structured design and to help understanding metabolism.