In English

Effect of nanotopography on bacterial adhesion and EPS production.

Neda Najafinobar
Göteborg : Chalmers tekniska högskola, 2011. 51 s.
[Examensarbete på avancerad nivå]

Bacterial infection after surgeries is a serious problem that cannot be treated by traditional antibiotics because of antimicrobial resistance and biofilm formation. Recently, a new coating (Bactiguard coating) has been developed that is able to reduce the infection significantly without compromising biocompatibility. This coating is comprised of nanosized deposits of Ag, Pd, and Au. It is not clear how this coating reduces infection. Therefore, this study aims to investigate how bacterial adhesion and production of extra cellular substances (EPS) are affected by surface nanotopography. However, the exact mechanism of action is not yet fully understood. The studied topographies are a flat and nanostructured gold surfaces. The fabrication method used was self-assembly with 20 to 30 nm gold nanoparticles. For the cell study staphylococcus epidermidis, was used. Bacterial cell adhesion and the formation of EPS were investigated. FilmTracer TM SYPRO Ruby biofilm matrix stain was used in order to stain EPS. In order to characterize the surfaces contact angle and scanning electron microscopy (SEM) were used. Dynamic light scattering and spectrophotometry was applied to analyze the size of the particles. SEM analyzed the number of cells attached on both surfaces. No ifference was observed on the number of cells attached on both surfaces. Quartz Crystal Microbalance with Dissipation Monitoring (QCM-D) was used to study the adhesion of bacteria and the production of EPS in real time. The results show that dissipation is lower on nanostructured surface that can be due to firmly attachment of bacterial cells on the surface and more production of EPS. Therefore, bacteria seem to behave differently when adsorbing on a flat or nanostructured surface.



Publikationen registrerades 2013-05-28. Den ändrades senast 2013-05-28

CPL ID: 177544

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