Glinel, KarineSomville, EléanaEléanaSomville2025-05-142025-05-142025-05-142016https://hdl.handle.net/2078.2/6718The understanding and control of bacterial biofilms are currently of great interest for the industrial and medical field. Several strategies are investigated to control biofilm formation including antifouling and bactericidal coatings, as well as topographical patterns. In this work, different surface functionalization and nanofabrication techniques have been combined to produce new surfaces to control bacterial organization. Indeed, antifouling hydrophilic polymer brushes were successfully nanopatterned then grafted with bioactive peptides to create innovating chemically nanopatterned surfaces. In order to investigate the influence of the pattern characteristics on the bacterial behavior, two different pattern dimensions (250 pattern and 400 pattern) were prepared. Moreover, three different peptides were grafted on the patterned brushes : a RGD peptide, well-known for its key role in eukariotic cell adhesion and the two antimicrobial peptides (AMPs), LL37 and magainin I known for their antibacterial properties against Escherichia coli (E. coli), a gram-negative bacteria that was used to investigate the influence of these surfaces on bacterial growth, organization and viability. First, chemical nanopatterns were found to have an indirect influence on bacterial behaviour. Indeed, no clear bacterial alignment nor specific arrangement of dead bacteria was observed on any of the tested surfaces. However, nanopatterned RGD-grafted surfaces clearly induced a higher growth compared to homogeneous RGD-grafted surfaces. Similarly, 400-patterned LL37-grafted surfaces showed a higher killing activity than 250-patterned and homogeneous LL37-grafted surfaces. However, this effect was not observed for MAG-grafted surfaces. Secondly, it was observed that AMP-grafted surfaces were not as effective as expected to kill bacteria : almost no dead bacteria were observed after 1h and about only 20% were dead after 7h-growth. Further research needs to be done to fully understand the influence of the chemical patterns on the surface proliferation of bacteria. In order to do so, it would be interesting to use different pattern geometries and dimensions as well as different bacterial species. Similarly, further research is most certainly needed to optimize the killing activity of AMP-grafted surfaces.Chemical nanopatterningPolymer brushBacteriaBiofilmRGD peptideAntimicrobial peptidesLL37Magainin Itext::thesis::master thesisthesis:4586