Studies on Light Induced Dynamics of Small Molecules and Protein under Different Physiological Conditions in Lipid Nanoparticles and Vesicles

Das, Shrabanti (2017) Studies on Light Induced Dynamics of Small Molecules and Protein under Different Physiological Conditions in Lipid Nanoparticles and Vesicles. PhD thesis, Indian Institute of Science Education and Research Kolkata.

PDF (PhD thesis of Shrabanti Das (11IP12)) 11IP12_PhD.pdf - Submitted Version Restricted to Repository staff only Download (9MB)

Abstract

The dissertation presents a proposition about the interaction of some small molecules and protein with various types of lipid aggregates. The pH sensitivity of flavonoid molecule fisetin embedded in solid lipid nanoparticles introduces its application in pharmaceuticals. It was observed that fisetin shows sharp changes in photophysical behaviour by the limited percolation of H+ and OH- ions while incorporated in solid lipid nanoparticles without any structural modification of SLN. Under UVC exposure the secondary structural motif of protein was observed to be protected by gold clusters produced in situ and in turn proved to be best as produced ex-situ. The protecting behaviour was equally observed in aqueous media as well as in lipid vesicles. Thioflavin T, a benzothiazole dye being positively charged is prone to attach with the negatively charged phosphate backbone of DNA. This dye shows selectivity in a binding motif in sequence exchanged single strand DNAs and consequently acts as an anchor to bind ssDNA with anionic liposomes. This type of dyes can also distinguish the liposomal surface charges by the formation of dimers on cationic liposome only. It also has been shown that the liposomal surface charge even the size can also tune the metal to ligand charge transfer (MLCT) property as demonstrated by the specially designed cyclometalated dinuclear metal complex. A new method was developed using tagged lipid vesicles to track the penetration of neurotransmitter in a lipid bilayer with the assist of fluorescence lifetime imaging microscopy (FLIM). The observation shows a deeper penetration of neurotransmitter towards the bilayer. It also has been shown that introduction of excess negatively charged liposomes can alter the aggregation property of asymmetric cyanine dye present superficially on liposomes. The above-mentioned works presented interesting results that persuade one to investigate this area further.

Actions (login required)

View Item