| Methicillin-resistant Staphylococcus aureus (MRSA) is any strain of Staphylococcus aureus that has developed resistance to beta-lactam antibiotics, including the penicillins and the cephalosporins. Once confined to hospital settings, MRSA can now be contracted in community settings as well. Although many new antibiotics against MRSA are in phase II and III clinical trials, a tool that would enable the recognition of MRSA through its membrane structure could lead to new therapeutic approaches to eradicate the MRSA superbug, either without the use of antibiotics or with a strain-specific antibiotic. Therefore, since the aptamer molecule has shown outstanding target-specific binding, this study presents the generation of four MRSA strain-specific aptamers that can be easily modified as molecular probes for bioanalysis or antibiotics-free therapy. The Cell-SELEX technology was used to develop target-specific aptamers. Binding studies of those aptamers were performed by flow cytometry on a panel of clinical strains and preliminary investigation of their use after chemical modifications using AuNP was also carried out until no more binding of the aptamers was observed over time.;Cancer is commonly referred to as the disease of our century. While budgets of billions dollars are granted toward cancer research, very little improvement is observed statistically. Liver cancer, which usually occurs on liver suffering of cirrhosis, shows a very low survival rate. The hepatocellular carcinoma is the most common liver cancer and the protein GPC3 is over-expressed on cancer patients. For that reason, GPC3 is a good candidate for early cancer detection or diagnosis. We used an hGPC3- overexpressed mouse cancer cell line (IMEA) to study aptamer generation specific to GPC3. In this study, no aptamers were found to be specific to the protein; this raises questions about the stability and the quality of such cell lines. Finally, another cancer cell line, the ovarian cancer cells TOV21G, for which aptamers had been developed in the past from our research group, was used to study the cytotoxicity of the gold-nanorods through thermoactivation. Results of this study showed that the aptamer TOV6-gold-nanorod complex was able to internalize in the ovarian cancer cell and showed cytotoxicity after thermoactivation through an NIR laser beam. |
