Surface modification using layer-by-layer method for antimicrobial applications

• Main Author: Sim, Sherlyne Xiu Hui.
• Other Authors: Chan Vincent
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Chemical engineering::Biotechnological production
• Online Access: http://hdl.handle.net/10356/16622
• Institution: Nanyang Technological University

The modification of biomedical device surfaces with materials that exhibit antimicrobial properties has been shown to potentially reduce the possibility of infections. An infection arises from the accumulation of bacteria on the surface, forming a layer of biofilm. It is important to prevent the formation of biofilm by modifying the properties of the surface. In this study, Chitosan and Dextran was used due to its contact active anti-bacterial and microbe repelling anti-adhesive properties respectively. Layer-by-layer assembly approach was chosen for the multilayer fabrication. The assembly process of the multilayer was monitored using contact angle measurements and UV-visible absorption spectrometer. The ability for cell adhesion was investigated through 3T3 fibroblast cell culture. While the ability of these surfaces in conferring antimicrobial properties in the presence of bacteria, Staphylococcus aureus (S.aureus), was investigated. In addition, the effect of RGD on these surfaces was also studied. The results indicates that Chitosan and Dextran multilayer, with Dextran as the outermost layer, inhibits cell adhesion. RGD-grafted surfaces significantly enhance cell adhesion as compared to un-treated amino glass. Bacterial adhesion results show that the multilayer without RGD, exhibit good antimicrobial, in particular anti-adhesive, properties. In contrast, the amount of S.aureus increases with RGD which is not within the expected results. RGD promotes the specific binding between host cell and biomedical devices; it should not have a significant effect on bacterial adhesion.