Greffage de peptides pour limiter les infections sur des prothèses intraosseuses transcutanées pour amputations (ITAP)

Authors: Ghribi, Nawel
Advisor: Laroche, Gaétan
Abstract: Intraosseous Transcutaneous Amputation Prostheses (ITAPs) represent apromising alternative to orthopedic prostheses currently used in the clinic since they could reduce, among other things, pain and discomfort in patients. However, infection, especially at the implant / skin interface, remains a significant complicationin this type of orthopedic surgery. The aim of this research project is therefore to limit infections on a titanium alloy prosthesis (Ti6Al4V ELI). Two approaches have been established. The first is to promote the adhesion of skin cells by using the KRGDS and KYIGSR peptides, which would seal the part of the implant that comes out of the bone and thus limit infections and the second to act directly on bacteria by eliminating them, by using the antimicrobial peptide, Mag 2. For this thesis work, the two adhesion peptides, either KRGDS or KYIGSR and the antimicrobial peptide, Mag 2, were covalently grafted via the phosphonate and dopamine anchor arms to the surface of the Ti6Al4V ELI material. The physico-chemical characterization of these surfaces made it possible to validate the covalent and stable grafting of these peptides. Cellular and bacterial tests were carried out on bare Ti6Al4V ELI surfaces and functionalized by the various peptides. For cellular assays, there is good celladhesion and proliferation of dermal fibroblasts on the 4 types of Ti6Al4V ELI samples. In contrast, cell viability is improved for samples with grafted peptides,especially KRGDS and Mag 2. Moreover, dermal attachment is significantly betteron surfaces functionalized by Mag 2 as well. Regarding microbiology tests, the results obtained with Staphylococcus epidermidis ATCC12228 bacteria show a slight antibacterial effect of Mag 2 grafted onto the Ti6Al4V ELI surface. Within the framework of this project, the surface functionalization by the antimicrobial peptide Mag 2 is the best alternative to limit infections on Ti6Al4V ELI materials
Document Type: Thèse de doctorat
Issue Date: 2021
Open Access Date: 7 June 2021
Grantor: Université Laval
Collection:Thèses et mémoires

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