Maskless direct cell patterning by laser writing

A simple and effective method for patterning cell on glass substrate is reported. A passivation layer that is capable of preventing cell adhesion was first coated onto glass surface. The passivation coatings that were tested include 3-[Bis(2-hydroxyethyl)amino]propyl-triethoxysilane, 3-Aminopropyltriethoxysilane, 1H, 1H, 2H, 2H-Perfluorodecyl-triethoxysilane, 3 -Glycidyloxypropyltriethoxysilane, Octade cyltrimethoxysilane, and Octadecyltrichlorosilane. A CO₂ laser and a UV laser were used to remove the passivation layer and define patterns according to user design. Cell arrays and arbitrary pattern were demonstrated. The minimal feature attainable by the CO₂ laser is about 100 mum. The minimal feature for reliable cell adhesion is found to be about 25 mum. Cells adhere and grow cleanly in the laser defined pattern. The pattern can be re-designed and fabricated easily and rapidly. Living cell staining by CMFDA and antibody staining for epidermal growth factor receptor (EGFR) detection were successfully performed on the surface bound cells. This method can be very useful for developing drug screening tools that utilize cell-based detection