Importance of light activation for plant Cryptochrome and antibacterial drug delivery strategies
Date of Award
Doctor of Philosophy (PhD)
Biomedical and Chemical Engineering and Sciences
Maria Pozo de Fernandez
The goal of this project is to investigate the benefits of applying light in different systems. In the first part, the magnetoreception process that occurs in the lightactivated cryptochrome of Arabidopsis Thaliana was investigated. In the second part, photo-carbon monoxide releasing molecules (photo-CORMs) were investigated for their antibacterial effect to develop biomedical strategies. Overall, this has been achieved in three different studies. The first study investigated if the forward lightdriven reaction is involved in the magnetoreception process or not in cryptochrome (CRY). To accomplish this, the plant seedlings were tested for 90 minutes as follows: 5 minutes in the light and 10 minutes in the dark. The in vivo phosphorylated cryptochrome was then measured directly and quantitatively by western blotting under the influence of a 500 μT static magnetic field (SMF). Second, the quantitative plant hypocotyl growth assay was tested. This has eliminated the possibility that that short-lived radical pairs produced in the light-driven reaction could be involved in the magnetic sensitivity of Arabidopsis Thaliana. In the second study, the magnetic sensitivity of CRY was investigated during interaction with different types of magnetic fields. Therefore, the Radiofrequency (RF) Magnetic Field and the Low- Level Field (LLF) were applied to confirm the effect of the weak static magnetic fields on the light-activated cryptochrome biological activity. This was detected via various quantitative assays to measure the cryptochrome response, including the phosphorylation assay, the hypocotyl growth assay, and the quantitative polymerase chain reaction (qPCR). This study demonstrated that RF and LLF significantly reduced cry activity, resulting in an increase in hypocotyl length. In the third study, the second part of the project aimed to use the light trigger strategy to investigate the antibacterial effect of CO. This was done through the activation of photo-CORMs to deliver controlled doses of CO upon activation. Scanning electron microscope (SEM) and zone of inhibition assay were used to study the effect of CO on E. coli. These results have shown that an organic diketone photo-CORM (DK4) compound has a dose-dependent antibacterial effect that affects bacterial cells' attachment to the substrate and biofilm maturation.
Hammad, Merfat Ahmed, "Importance of light activation for plant Cryptochrome and antibacterial drug delivery strategies" (2022). Theses and Dissertations. 747.
Available for download on Sunday, December 17, 2023
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