{"id":{"repo_id":"kings","oai_identifier":"oai:kclpure.kcl.ac.uk:studenttheses/9868d81f-3986-41d2-a3a4-a06f6b36a46b"},"canonical_url":"https://search.dev.ndltd.org/etd/kings/oai:kclpure.kcl.ac.uk:studenttheses/9868d81f-3986-41d2-a3a4-a06f6b36a46b","repository":{"repo_id":"kings","name":"King's College London","base_url":"https://kclpure.kcl.ac.uk/ws/oai"},"display":{"title":"Cationic lipid formaulation of short interference RNA (siRNA) for delivery to respiratory epithelial cells","abstract":"Cationic lipids are commonly used and relatively safe vectors for plasmid
(pDNA) delivery. In search for an optimal lipid-based formulation for siRNA
delivery to the lungs, cationic lipid-based carriers were investigated for the delivery of siRNA in comparison with pDNA delivery. The aim was to determine whether the factors that influence cationic-lipid mediated pDNA delivery would similarly affect siRNA delivery.
Plasmid DNA encoding for luciferase and GAPDH siRNA were complexed
using three model cationic lipid-based systems; DOTAP:DOPE,
DOTAP:DOPE:DMPE-PEG5000, DOTAP:DOPE:protamine. Cationic lipid/pDNA
(+/-) charge ratio of 2 or greater complexed pDNA most efficiently, while much
higher ratios (≥ 10) were still less efficient in complexing siRNA. pDNA complexes
were larger (up to 4 μm) and formed aggregates in physiological buffer, compared to water, whereas siRNA complexes remained small (<300 nm). Gene silencing in bronchial and alveolar cell lines Calu-3 and A549 revealed a dependency on high lipid/siRNA (+/-) charge ratio (> 8) compared to the delivery of pDNA complexes (0.5-1). Confocal microscopy and endocytic inhibitors studies indicated that the cellular uptake of siRNA/lipid complexes was via a temperature-dependent pathway, which lead to the vesicular localisation of siRNA in the peri-nuclear region. Gene silencing activity was not dependent on the endocytosis-mediated uptake of the complexes. In conclusion, important differences in the factors that affect of siRNA versus pDNA delivery were revealed: the optimal properties of gene silencing were different depending on the nucleic acid and the lipid used. DOTAP:DOPE:DMPE PEG5000 and DOTAP:DOPE:protamine at charge ratios 8-10 delivered siRNA most
effectively.","abstract_html":"Cationic lipids are commonly used and relatively safe vectors for plasmid<br/>(pDNA) delivery. In search for an optimal lipid-based formulation for siRNA<br/>delivery to the lungs, cationic lipid-based carriers were investigated for the delivery of siRNA in comparison with pDNA delivery. The aim was to determine whether the factors that influence cationic-lipid mediated pDNA delivery would similarly affect siRNA delivery.<br/>Plasmid DNA encoding for luciferase and GAPDH siRNA were complexed<br/>using three model cationic lipid-based systems; DOTAP:DOPE,<br/>DOTAP:DOPE:DMPE-PEG5000, DOTAP:DOPE:protamine. Cationic lipid/pDNA<br/>(+/-) charge ratio of 2 or greater complexed pDNA most efficiently, while much<br/>higher ratios (≥ 10) were still less efficient in complexing siRNA. pDNA complexes<br/>were larger (up to 4 μm) and formed aggregates in physiological buffer, compared to water, whereas siRNA complexes remained small (<300 nm). Gene silencing in bronchial and alveolar cell lines Calu-3 and A549 revealed a dependency on high lipid/siRNA (+/-) charge ratio (> 8) compared to the delivery of pDNA complexes (0.5-1). Confocal microscopy and endocytic inhibitors studies indicated that the cellular uptake of siRNA/lipid complexes was via a temperature-dependent pathway, which lead to the vesicular localisation of siRNA in the peri-nuclear region. Gene silencing activity was not dependent on the endocytosis-mediated uptake of the complexes. In conclusion, important differences in the factors that affect of siRNA versus pDNA delivery were revealed: the optimal properties of gene silencing were different depending on the nucleic acid and the lipid used. DOTAP:DOPE:DMPE PEG5000 and DOTAP:DOPE:protamine at charge ratios 8-10 delivered siRNA most<br/>effectively.","abstract_has_math":false,"creators":["Betkaoui, Radia"],"institution":"King's College London","degree_name":"Doctor of Philosophy","degree_level":"Doctoral Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Forbes, Benjamin John","Patel, Nilesh"],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-5-21","date_published":"2012-5-21","updated_at":"2026-07-24T02:44:34Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:kclpure.kcl.ac.uk:studenttheses/9868d81f-3986-41d2-a3a4-a06f6b36a46b"],"render_values":[{"text":"oai:kclpure.kcl.ac.uk:studenttheses/9868d81f-3986-41d2-a3a4-a06f6b36a46b","href":null,"code":true}]}]},"links":{"outbound_url":"https://kclpure.kcl.ac.uk/portal/en/studentTheses/9868d81f-3986-41d2-a3a4-a06f6b36a46b","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Forbes, Benjamin John","Patel, Nilesh"]},{"key":"dc:creator","label":"Author","values":["Betkaoui, Radia"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2012-5-21"]},{"key":"dc:date.issued","label":"Date","values":["2012-5-21"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Institute of Pharmaceutical Science"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["King's College London"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://kclpure.kcl.ac.uk/portal/en/studentTheses/9868d81f-3986-41d2-a3a4-a06f6b36a46b"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral Thesis"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:kclpure.kcl.ac.uk:studenttheses/9868d81f-3986-41d2-a3a4-a06f6b36a46b","https://kclpure.kcl.ac.uk/portal/en/studentTheses/9868d81f-3986-41d2-a3a4-a06f6b36a46b"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://kclpure.kcl.ac.uk/portal/files/12490825/Studentthesis-Radia_Betkaoui_2012.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Cationic lipids are commonly used and relatively safe vectors for plasmid
(pDNA) delivery. In search for an optimal lipid-based formulation for siRNA
delivery to the lungs, cationic lipid-based carriers were investigated for the delivery of siRNA in comparison with pDNA delivery. The aim was to determine whether the factors that influence cationic-lipid mediated pDNA delivery would similarly affect siRNA delivery.
Plasmid DNA encoding for luciferase and GAPDH siRNA were complexed
using three model cationic lipid-based systems; DOTAP:DOPE,
DOTAP:DOPE:DMPE-PEG5000, DOTAP:DOPE:protamine. Cationic lipid/pDNA
(+/-) charge ratio of 2 or greater complexed pDNA most efficiently, while much
higher ratios (≥ 10) were still less efficient in complexing siRNA. pDNA complexes
were larger (up to 4 μm) and formed aggregates in physiological buffer, compared to water, whereas siRNA complexes remained small (<300 nm). Gene silencing in bronchial and alveolar cell lines Calu-3 and A549 revealed a dependency on high lipid/siRNA (+/-) charge ratio (> 8) compared to the delivery of pDNA complexes (0.5-1). Confocal microscopy and endocytic inhibitors studies indicated that the cellular uptake of siRNA/lipid complexes was via a temperature-dependent pathway, which lead to the vesicular localisation of siRNA in the peri-nuclear region. Gene silencing activity was not dependent on the endocytosis-mediated uptake of the complexes. In conclusion, important differences in the factors that affect of siRNA versus pDNA delivery were revealed: the optimal properties of gene silencing were different depending on the nucleic acid and the lipid used. DOTAP:DOPE:DMPE PEG5000 and DOTAP:DOPE:protamine at charge ratios 8-10 delivered siRNA most
effectively."]},{"key":"dc:title","label":"Title","values":["Cationic lipid formaulation of short interference RNA (siRNA) for delivery to respiratory epithelial cells"]}]}],"canonical_facts":{"dc:contributor.advisor":["Forbes, Benjamin John","Patel, Nilesh"],"dc:creator":["Betkaoui, Radia"],"dc:date":["2012-5-21"],"dc:date.issued":["2012-5-21"],"dc:description.abstract":["Cationic lipids are commonly used and relatively safe vectors for plasmid
(pDNA) delivery. In search for an optimal lipid-based formulation for siRNA
delivery to the lungs, cationic lipid-based carriers were investigated for the delivery of siRNA in comparison with pDNA delivery. The aim was to determine whether the factors that influence cationic-lipid mediated pDNA delivery would similarly affect siRNA delivery.
Plasmid DNA encoding for luciferase and GAPDH siRNA were complexed
using three model cationic lipid-based systems; DOTAP:DOPE,
DOTAP:DOPE:DMPE-PEG5000, DOTAP:DOPE:protamine. Cationic lipid/pDNA
(+/-) charge ratio of 2 or greater complexed pDNA most efficiently, while much
higher ratios (≥ 10) were still less efficient in complexing siRNA. pDNA complexes
were larger (up to 4 μm) and formed aggregates in physiological buffer, compared to water, whereas siRNA complexes remained small (<300 nm). Gene silencing in bronchial and alveolar cell lines Calu-3 and A549 revealed a dependency on high lipid/siRNA (+/-) charge ratio (> 8) compared to the delivery of pDNA complexes (0.5-1). Confocal microscopy and endocytic inhibitors studies indicated that the cellular uptake of siRNA/lipid complexes was via a temperature-dependent pathway, which lead to the vesicular localisation of siRNA in the peri-nuclear region. Gene silencing activity was not dependent on the endocytosis-mediated uptake of the complexes. In conclusion, important differences in the factors that affect of siRNA versus pDNA delivery were revealed: the optimal properties of gene silencing were different depending on the nucleic acid and the lipid used. DOTAP:DOPE:DMPE PEG5000 and DOTAP:DOPE:protamine at charge ratios 8-10 delivered siRNA most
effectively."],"dc:identifier":["oai:kclpure.kcl.ac.uk:studenttheses/9868d81f-3986-41d2-a3a4-a06f6b36a46b","https://kclpure.kcl.ac.uk/portal/en/studentTheses/9868d81f-3986-41d2-a3a4-a06f6b36a46b"],"dc:identifier.uri":["https://kclpure.kcl.ac.uk/portal/files/12490825/Studentthesis-Radia_Betkaoui_2012.pdf"],"dc:language":["eng"],"dc:publisher.department":["Institute of Pharmaceutical Science"],"dc:publisher.institution":["King's College London"],"dc:relation.isreferencedby":["https://kclpure.kcl.ac.uk/portal/en/studentTheses/9868d81f-3986-41d2-a3a4-a06f6b36a46b"],"dc:title":["Cationic lipid formaulation of short interference RNA (siRNA) for delivery to respiratory epithelial cells"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral Thesis"],"dc:type.qualificationname":["Doctor of Philosophy"]},"updated_at":"2026-07-24T02:44:34Z"}