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ABSTRACT: The present work aimed at designing a lipid-based nanocarrier for siRNA delivery toward two cell sub-populations within breast tumors, the cancer and the endothelial cells from angiogenic tumor blood vessels. To achieve such goal, the F3 peptide, which is specifically internalized by nucleolin overexpressed on both those sub-populations, was used as a targeting moiety. The developed F3-targeted stable nucleic acid lipid particles presented adequate features for systemic administration. In addition, the attachment of the F3 peptide onto the liposomal surface enabled an internalization by both cancer and endothelial cells from angiogenic blood vessels that was significantly higher than the one observed with non-cancer cells. Sequence-specific downregulation of enhanced green fluorescent protein (eGFP) in eGFP-overexpressing human cancer cell lines, both at the protein and mRNA levels, was further observed upon delivery of anti-eGFP siRNA by F3-targeted liposomes, in contrast with the non-targeted counterpart. This effect was highly dependent on the content of poly(ethylene glycol) (PEG), as evidenced by the co-localization studies between the siRNA and the lysosomes. Overall, the present work represents an important contribution toward a nanoparticle with multi-targeting capabilities in breast cancer, both at the cellular and molecular level.
International journal of pharmaceutics 05/2012; 434(1-2):9-19. · 2.96 Impact Factor
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ABSTRACT: About 1.5 million new cases of cutaneous leishmaniasis and 500,000 new cases of visceral leishmaniasis occur each year around the world. For over half a century, the clinical forms of the disease have been treated almost exclusively with pentavalent antimonial compounds. In this review, we describe the arsenal available for treating Leishmania infections, as well as recent advances from research on plants and synthetic compounds as source drugs for treating the disease. We also review some new drug-delivery systems for the development of novel chemotherapeutics. We observe that the pharmaceutical industry should employ its modern technologies, which could lead to better use of plants and their extracts, as well as to the development of synthetic and semi-synthetic compounds. New studies have highlighted some biopharmaceutical technologies in the design of the delivery strategy, such as nanoparticles, liposomes, cochleates, and non-specific lipid transfer proteins. These observations serve as a basis to indicate novel routes for the development and design of effective anti-Leishmania drugs.
International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 05/2011; 15(8):e525-32. · 2.17 Impact Factor
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ABSTRACT: Anticancer systemic gene silencing therapy has been so far limited by the inexistence of adequate carrier systems that ultimately provide an efficient intracellular delivery into target tumor cells. In this respect, one promising strategy involves the covalent attachment of internalizing-targeting ligands at the extremity of PEG chains grafted onto liposomes. Therefore, the present work aims at designing targeted liposomes containing nucleic acids, with small size, high encapsulation efficiency and able to be actively internalized by SCLC cells, using a hexapeptide (antagonist G) as a targeting ligand. For this purpose, the effect of the liposomal preparation method, loading material (ODN versus siRNA) and peptide-coupling procedure (direct coupling versus post-insertion) on each of the above-mentioned parameters was assessed. Post-insertion of DSPE-PEG-antagonist G conjugates into preformed liposomes herein named as stabilized lipid particles, resulted in targeted vesicles with a mean size of about 130 nm, encapsulation efficiency close to 100%, and a loading capacity of approximately 5 nmol siRNA/mumol of total lipid. In addition, the developed targeted vesicles showed increased internalization in SCLC cells, as well as in other tumor cells and HMEC-1 microvascular endothelial cells. The improved cellular association, however, did not correlate with enhanced downregulation of the target protein (Bcl-2) in SCLC cells. These results indicate that additional improvements need to be performed in the future, namely by ameliorating the access of the nucleic acids to the cytoplasm of the tumor cells following receptor-mediated endocytosis.
Biochimica et Biophysica Acta 12/2009; 1798(3):433-41. · 4.66 Impact Factor
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ABSTRACT: Copaiba oil has been used in folk medicine since the 19th century. The use of copaiba oils to treat leishmaniasis is cited in several ethnopharmacological studies. Nevertheless, the potential antileishmania of copaiba oils had not been studied.
Eight different kinds of Brazilian copaiba oils were screened for antileishmanial activity.
The antiproliferative effect of copaiba oil on promastigote and amastigote axenic were determined. To determine the survival index peritoneal macrophage were infected with promastigotes of Leishmania amazonensis and treated with copaiba oil. The cytotoxic effect of copaiba oil was assessed on macrophage strain J774G8 by assay of sulforhodamine B.
Copaiba oils showed variable levels of activity against promastigote forms with IC(50) values in the range between 5 and 22microg/mL. The most active oil was that from Copaifera reticulata (collected in Pará State, Brazil) with IC(50) values of 5, 15, and 20microg/mL for promastigote, axenic amastigote and intracellular amastigote forms, respectively. Amphotericin B showed IC(50) of 0.058 and 0.231microg/mL against promastigote and amastigote forms, respectively. Cytotoxicity assay showed that this copaiba oil obtained from Copaifera reticulata showed low cytotoxicity against J774G8 macrophages.
Copaiba oils showed significant activity against the parasite Leishmania amazonensis.
Journal of Ethnopharmacology 09/2008; 120(2):204-8. · 3.01 Impact Factor
