Bacterial interactions with nanostructured surfaces

Nanostructured surfaces are called “promising” to control bacterial adhesion and biofilm formation. Initial adhesion is followed by emergence of surface-programmed bacterial properties and biofilm growth. A easy distinction between nanostructured surfaces can be made on basis of periodic- or random-occurrence of nanostructured features, although often nanostructured surfaces are microstructured due to merging of their nanofeatures. Characterization of nanostructured surfaces is not trivial due to the myriad of different nanoscaled morphologies. Both superhydrophobic and hydrophilic, nanostructured surfaces generally yield low bacterial adhesion. On smooth surfaces, bacteria deform when adhering, causing membrane surface tension changes and accompanying responses yielding emergent properties. Adhesion to nanostructured surfaces, causes multiple cell wall deformation sites when bacteria are adhering in valleys, while in case of hill-top adhesion, highly localized cell wall deformation occurs. Accordingly, bacterial adhesion to nanostructured surfaces yields emergent responses that range from pressure-induced EPS production to cell wall rupture and death, based upon which nanostructured surfaces are consistently called “promising” for bacterial adhesion and biofilm control. Other promising features of nanostructured surfaces are increased antibiotic housing, thermal effects and photo-induced ROS production, but the latter two promises are largely based on properties of suspended nanoparticles and may not hold when particles are comprised in nanostructured coatings or materials. Moreover, in order to bring nanostructured coatings and materials to application, experiments are needed that go beyond the current limit of the laboratory bench.