Antibacterial Surfaces

Md Imrul Kayes1, Kashkoush Mohamed1, Galante Anthony1, Leu Paul2

  • 1University of Pittsburgh
  • 2University of Massachusetts-Amherst

Details

15:30 - 16:15 | Wed 26 Jul | Marquis Ballroom Foyer | WePPP.24

Session: Poster I

Abstract

Infections due to bacterial adhesion is very common for implanted medical devices and extensive research is being done to address this issue. Antibacterial surfaces generally either make the bacterial attachment process difficult because of the surface morphology, or kill the bacteria cells while in contact to the surface. These surfaces can be prepared by modifying the surface chemistry of a substrate, by modifying the hydrophilicity of a substrate, and by incorporating nanostructures on the surface. Currently, we are conducting two different studies to evaluate the adhesion and killing of bacteria cells by antibacterial surfaces. Staphylococcus epidermidis is a common source of infections on indwelling medical devices such as catheter. To evaluate the mechanical bactericidal effect on this bacteria, we prepared uniform and regular silicon nanoneedle arrays. The morphology of these structures were varied and optimized. The bactericidal nature of the nanostructures on cicada wings and black silicon, was demonstrated in recent research. But these structures lack uniformity, both in terms of distribution of the structures and their shape. We have been able to fabricate uniform and regular nanoneedle arrays with control over pitch, diameter, taper, and height. Nanosphere lithography and deep reactive ion etching were utilized to prepare various silicon nanostructure arrays of different morphology. Our results demonstrate that these structures have a mechanical bactericidal effect on staphylococcus epidermidis and we present results on how morphology affects this killing rate. Cases for contact lenses are generally made of Polypropylene (PP). Fungal and bacterial contamination is a common issue for these cases. We prepared different substrates by modifying the surface of the PP by reactive ion etching. The hydrophilicity of the surface was varied and contact angles were measured from 15 up to 150 degrees. The SEM, AFM and XPS images of the substrates were obtained. The adhesion tests were conducted with a common bacteria-Escherichia coli (E. Coli). The results demonstrate significant reduction in attachment of E. Coli on the hydrophilic substrates compared to the control and hydrophobic samples.