title: Direct-write patterning of bacterial cells by dip-pen nanolithography.
abstract: The ability of dip-pen nanolithography (DPN) to generate nano- or microarrays of soft or hard materials (e.g., small molecules, DNA, proteins, nanoparticles, sols, and polymers) in a direct-write manner has been widely demonstrated. The transporting of large-sized ink materials such as bacteria, however, remains a significant challenge with this technique. The size limitation of the water meniscus formed between the DPN tip and the solid surface becomes a bottleneck in such diffusion-based molecular transport experiments. Herein, we report a straightforward "stamp-on" DPN method that uses a nanostructured poly(2-methyl-2-oxazoline) hydrogel-coated tip and carrier agents to generate patterns of micrometer-sized  Escherichia coli  JM 109 bacterial cells. We demonstrate that this approach enables the deposition of a single bacterial cell array on a solid surface or arrays of layers of multiple cells by modulating the viscosity of the "ink" solution. Fluorescence microscopy images indicated that the deposited bacterial cells were kept alive on Luria-Bertani-agar layered solid surfaces after DPN patterning.
authors.affiliation: Department of Polymer Science and Technology, Korea National University of Transportation, Chungju 380-702, Korea.
authors.forename: Jieun
authors.initials: J
authors.lastname: Kim
authors.forename: Young-Hun
authors.initials: YH
authors.lastname: Shin
authors.forename: Seong-Hun
authors.initials: SH
authors.lastname: Yun
authors.forename: Dong-Sik
authors.initials: DS
authors.lastname: Choi
authors.forename: Ji-Hye
authors.initials: JH
authors.lastname: Nam
authors.forename: Sung Ryong
authors.initials: SR
authors.lastname: Kim
authors.forename: Sung-Kwon
authors.initials: SK
authors.lastname: Moon
authors.forename: Bong Hyun
authors.initials: BH
authors.lastname: Chung
authors.forename: Jae-Hyuck
authors.initials: JH
authors.lastname: Lee
authors.forename: Jae-Ho
authors.initials: JH
authors.lastname: Kim
authors.forename: Ki-Young
authors.initials: KY
authors.lastname: Kim
authors.forename: Kyung-Min
authors.initials: KM
authors.lastname: Kim
authors.forename: Jung-Hyurk
authors.initials: JH
authors.lastname: Lim
mesh_terms: D004926:Escherichia coli / Q000166:cytology*; D020100:Hydrogels / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D011073:Polyamines / Q000737:chemistry*; D046888:Tissue Array Analysis / Q000379:methods*
chemical_list: D020100:Hydrogels; D011073:Polyamines; C117403:poly(2-methyl-2-oxazoline)