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Full-Text Articles in Dentistry

Mechanisms Of Gene Transfer Mediated By Lipoplexes Associated With Targeting Ligands Or Ph-Sensitive Peptides, Sérgio Simões, Vladimir Slepushkin, Pedro Pires, Rogério Gaspar, Maria C. Pedroso De Lima, Nejat Düzgüneş Nov 1999

Mechanisms Of Gene Transfer Mediated By Lipoplexes Associated With Targeting Ligands Or Ph-Sensitive Peptides, Sérgio Simões, Vladimir Slepushkin, Pedro Pires, Rogério Gaspar, Maria C. Pedroso De Lima, Nejat Düzgüneş

All Dugoni School of Dentistry Faculty Articles

Association of a targeting ligand such as transferrin, or an endosome disrupting peptide such as GALA, with cationic liposome-DNA complexes ('lipoplexes') results in a significant enhancement of transfection of several cell types. Although these strategies can overcome some of the barriers to gene delivery by lipoplexes, the mechanisms by which they actually enhance transfection is not known. In studies designed to establish the targeting specificity of transferrin, we found that apo-transferrin enhances transfection to the same extent as transferrin, indicating that internalization of the lipoplexes is mostly independent of transferrin receptors. These observations were reinforced by results obtained from competitive …


Interaction Of Cationic Liposomes And Their Dna Complexes With Monocytic Leukemia Cells, Pedro Pires, Sérgio Simões, Shlomo Nir, Rogério Gaspar, Nejat Düzgüneş, Maria C. Pedroso De Lima Apr 1999

Interaction Of Cationic Liposomes And Their Dna Complexes With Monocytic Leukemia Cells, Pedro Pires, Sérgio Simões, Shlomo Nir, Rogério Gaspar, Nejat Düzgüneş, Maria C. Pedroso De Lima

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Cationic liposomes complexed with DNA have been used extensively as non-viral vectors for the intracellular delivery of reporter or therapeutic genes in culture and in vivo. We examined the relationship between the characteristics of the lipoplexes, their mode of interaction with monocytic THP-1 cells and their ability to transfect these cells. We determined the size and ζ potential of cationic liposomes (composed of 1,2-dioleoyl-3-(trimethylammonium) propane (DOTAP) and its mixtures with neutral lipids), and lipoplexes at different (+/-) charge ratios. As the (+/-) charge ratio of the lipoplexes decreased to (1/1), a significant reduction in ζ potential and an increase in …


Transfection Of Human Macrophages By Lipoplexes Via The Combined Use Of Transferrin And Ph-Sensitive Peptides, Sérgio Simões, Vladimir Slepushkin, Elizabeth Pretzer, Paul Dazin, Rogério Gaspar, Maria C. Pedroso De Lima, Nejat Düzgüneş Jan 1999

Transfection Of Human Macrophages By Lipoplexes Via The Combined Use Of Transferrin And Ph-Sensitive Peptides, Sérgio Simões, Vladimir Slepushkin, Elizabeth Pretzer, Paul Dazin, Rogério Gaspar, Maria C. Pedroso De Lima, Nejat Düzgüneş

All Dugoni School of Dentistry Faculty Articles

The crucial function of macrophages in a variety of biological processes and pathologies render these cells important targets for gene therapeutic interventions. Commonly used synthetic gene delivery vectors have not been successful in transfecting these non-dividing cells. A combination strategy involving cationic liposomes to condense and carry DNA, transferrin to facilitate cellular uptake, and the pH-sensitive peptide GALA to promote endosome destabilization, resulted in significant expression of a luciferase gene. Transfection of macrophages was dependent on the degree of differentiation of the cells. The quaternary complexes of cationic liposomes, DNA, transferrin, and GALA exhibited a net negative charge, which may …