Surface Functionalization And Structuring By Electron Beam For Enhanced Biological Response

Surface Functionalization And Structuring By Electron Beam For Enhanced Biological Response The aim of this master thesis is evaluating how micro and nano-topography could influence bacterial behavior. Micro and nano-topographies were realized on different Titanium alloys substrates, in particular Ti-6Al-4V, Ti-15Mo and CP Titanium (Grade 2) have been investigated by means of Electron Beam Welding machine. Finally, the bacterial behavior was tested with Staphylococcus aureus (SA, commercial, multi-drug resistant, ATCC 43300) in order to compare the evolution of bacterial proliferation on different modified substrates. The first part of the work took place at the Institute of Materials Science, Joining and Forming (IMAT-TUGraz) in Graz, where were realized the different Titanium alloys surfaces. There were used several techniques to modify the materials, such as Polishing Machine to polish samples in order to obtain a mirror shape polishing, Electron Beam Welding machine in order to create microtopography on the surface of the material through oriented micro grooves, Dilatometer in order to carry out some heat treatments on the specimens and modify micro and nanostructure of the material, Etching Treatments, using Hydrofluoric acid (HF), to create nano-topography on the samples. Some characterizations of the material were carried out in Graz, by means of Field Emission Scanning Electron Microscope (FESEM), by Light Optical Microscope (LOM) and by 3D Microscope in order to observe the surface of the samples and the cross section of them. The second part of the materials characterization was carried out at Dipartimento di Scienza Applicata e Tecnologia (DISAT) at Politecnico of Turin, in Turin, where surface wettability was tested by contact angle measurements (water), crystalline phases and roughness were investigated by means of XRD and surface profile measurements. Finally, biological tests were performed at Eastern Piedmont University in Novara, using Staphylococcus aureus (SA, commercial, multi-drug resistant, ATCC 43300). Bacterial viability was evaluated through AlamarBlue test and CFU count method, while bacterial morphology was observed using fluorescent microscope and FESEM.