[nanoPost] Anti-bacterial nanoparticulate thin films

The adhesion of bacteria to surfaces and its adverse consequences in the subsequent development of microbial biofilms has been the focus of this group’s research for some years.  They have focused on factors determining the initial adhesion of bacteria because they believe this step is critical to colonization of surfaces. They have developed sensitive infrared spectroscopic methods which can be used to study in situ the attachment of bacteria to wet metal surfaces and which are able to provide molecular information about the chemical nature of the adhesion.

The group employs nanotechnology in these experiments by using metal oxide (e.g. TiO2) nanoparticles in thin films as model metal (e.g. Ti) surfaces. This nanoparticle film approach is also applicable to materials other than metals. Through this work they have discovered that siderophores, iron sequestering molecules secreted by bacteria, appear to contribute to bacterial adhesion to metals of the Gram negative bacteria Pseudomonas aeruginosa and Escherischia coli. Improved knowledge of the chemical bonds formed during the attachment process can be used in strategies to prevent bacterial adhesion.

In a related project they are developing polymer based films of defined chemical composition and surface properties (flexibility, charge, hydrophobicity, topography) and they are determining the impact of these variables on the rate and strength of cell adhesion. The group is working predominantly with P. aeruginosa, but has experience in using microscopic and infrared spectroscopic techniques to examine the attachment of a wide range of bacterial species and even macro-fouling organisms (mussel spat) to surfaces.

They believe that a greater understanding of the impact of the physicochemical properties of surfaces on initial attachment processes will lead to the development of more effective and robust anti-fouling control regimes/technologies.

The group is interested in carrying out collaborative research with other groups working on the development of technologies to control biofouling. The strengths they could bring to any such group are in the employment of the novel in situ IR spectroscopic techniques they have developed for surface characterization and cell adhesion and in the growth and culture of micro and macro-fouling organisms to assess the physicochemical nature of surfaces, their propensity to foul and their ability to be cleaned.

This is a powerful approach to obtaining new adhesion knowledge of importance in the development of new strategies to prevent such adhesion. The approach may also be applied to materials other than metals.