Patterning Bacteria within Hyperbranched Polymer Film Templates

A four-step soft lithographic process based on microcontact printing (μCP) of organic monolayers, hyperbranched polymer grafting, and subsequent polymer functionalization, results in polymer/n-alkanethiol patterns that direct the seeding of bacterial cells. The functional units on these surfaces are three-dimensional bacteria “corrals” that are as small as 12 μm square. The corrals have hydrophobic, methyl-terminated n-alkanethiol bottoms, which promote bacterial adhesion, and walls consisting of hydrophilic poly(acrylic acid)/poly(ethylene glycol) layered nanocomposites that inhibit adhesion. Cell viability studies indicate that cells remain viable on the patterned surfaces. Large corrals (63 μm square) contain 18 ± 5 bacteria and smaller corrals (12 μm square) contain 2 ± 1 bacteria. Bacteria reside within corrals with a reliability of 92 ± 8%; the remaining cells reside on walls between corrals. Applications to bioarrays for high-throughput screening and biosensors are envisioned.