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dc.contributor.advisorJayaraman, N
dc.contributor.advisorDas, Saumitra
dc.contributor.authorLakshminarayanan, Abirami
dc.date.accessioned2018-06-05T11:35:43Z
dc.date.accessioned2018-07-30T15:14:05Z
dc.date.available2018-06-05T11:35:43Z
dc.date.available2018-07-30T15:14:05Z
dc.date.issued2018-06-05
dc.date.submitted2015
dc.identifier.urihttp://etd.iisc.ac.in/handle/2005/3663
dc.identifier.abstracthttp://etd.iisc.ac.in/static/etd/abstracts/4533/G27315-Abs.pdfen_US
dc.description.abstractDendrimers are synthetic macromolecules with branches-upon-branches structures, nanoscale dimensions and a high density of surface groups. Presence of multiple cationic sites in dendrimers permits their efficient nucleic acid complexation and cellular internalization through endocytic pathways. PETIM dendrimers of are characterized by tertiary amine branch points, and ether linkages. A third generation PETIM dendrimer, G3(NH2)24, with nitrogen at the core and twenty four peripheral primary amines was synthesized through alternate Michael addition and reduction reactions. The ability of G3(NH2)24 to interact with DNA was ascertained by spectroscopic and bio-physical techniques. These studies established the formation of dendrimer-DNA, and complex formation was also shown to protect the plasmid DNA from nucleases. Toxicity studies in cell culture, as well as, in female Balb/c mice established the non-toxic properties of the dendrimer. G3(NH2)24 was able to mediate efficient transfection in mammalian cells and in vivo. Targeted delivery of small interfering RNA (siRNA) to hepatocytes, in order to combat hepatitis C virus (HCV) infection was undertaken to expand the scope of PETIM dendrimer based gene delivery. Functionalization of the dendrimer periphery with galactose units ensured preferential delivery to the liver through multivalent interactions with the asialoglycoprotein receptors on the liver cell surface. The delivery of siRNA to the perinuclear region, in close proximity to the HCV RNA replication site resulted in ~75% decrease in viral RNA levels in replicon containing cells, as well as, JFH-1 infectious virus systems. The dendrimer-siRNA complexes were preferentially delivered to mice liver and were active in vivo. Physico-chemical studies of the protonation pattern of PETIM dendrimer indicated that the protonation of the dendrimer amines proceeded in a shell-wise pattern from the periphery to the core. The primary amines of the dendrimer as well as the outer shell tertiary amines with pKa values ~7-10 were protonated at physiological pH and were cationic sites for nucleic acid condensation. The inner shell tertiary amines with a pKa of ~4-6 were protonated at endosomal pH and aided ‘endosomal escape’ due to the high buffering capacity of 3.5. Work described in the Thesis establish a new synthetic dendrimer vector, namely, the series of PETIM dendrimers, as a high value gene delivery vector, making in-roads towards pre-clinical and possible clinical trials in future studies.en_US
dc.language.isoen_USen_US
dc.relation.ispartofseriesG27315en_US
dc.subjectDendrimersen_US
dc.subjectsiRNAen_US
dc.subjectDNA-PETIM Complexesen_US
dc.subjectPoly(Propyl Ether Imine) Dendrimersen_US
dc.subjectHepatitis C Virusen_US
dc.subjectPETIM Dendrimeren_US
dc.subjectDendrimer-DNA Complexationen_US
dc.subjectHepatitis C Inhibitionen_US
dc.subject.classificationOrganic Chemistryen_US
dc.titleStudies of Poly(Propyl Ether Imine) Dendrimers as Synthetic SiRNA Delivery Vectors with Relevance to Hepatitis C Virus Inhibitionen_US
dc.typeThesisen_US
dc.degree.namePhDen_US
dc.degree.levelDoctoralen_US
dc.degree.disciplineFaculty of Scienceen_US


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