Nanopillared Surfaces Disrupt Pseudomonas aeruginosa Mechanoresponsive Upstream Motility

Pseudomonas aeruginosa is an opportunistic,
multidrug-resistant, human pathogen that forms biofilms in environments
with fluid flow, such as the lungs of cystic fibrosis patients, industrial
pipelines, and medical devices. P. aeruginosa twitches upstream on surfaces by the cyclic extension and retraction
of its mechanoresponsive type IV pili motility appendages. The prevention
of upstream motility, host invasion, and infectious biofilm formation
in fluid flow systems remains an unmet challenge. Here, we describe
the design and application of scalable nanopillared surface structures
fabricated using nanoimprint lithography that reduce upstream motility
and colonization by P. aeruginosa.
We used flow channels to induce shear stress typically found in catheter
tubes and microscopy analysis to investigate the impact of nanopillared
surfaces with different packing fractions on upstream motility trajectory,
displacement, velocity, and surface attachment. We found that densely
packed, subcellular nanopillared surfaces, with pillar periodicities
ranging from 200 to 600 nm and widths ranging from 70 to 215 nm, inhibit
the mechanoresponsive upstream motility and surface attachment. This
bacteria-nanostructured surface interface effect allows us to tailor
surfaces with specific nanopillared geometries for disrupting cell
motility and attachment in fluid flow systems.