Biodistribution of liposome/DNA systems after subcutaneous and intraperitoneal inoculation.

In this work, we analyzed protein interaction, cell toxicity, and biodistribution of liposome formulation for further possible applications as DNA vehicles in gene-therapy protocols. In relation to protein interaction, cationic liposomes showed the lowest protein interaction, but this parameter was incremented with DNA association. On the other hand, noncharged liposomes presented high protein interaction, but DNA association decreased this parameter.

Antitumoral effect of IL-12 gene transfected via liposomes into B16F0 cells.

Murine melanoma B16F0 cells were transfected with SA:DPPC:DOPE (2:1:1 molar ratio) liposomes associated with a plasmid encoding murine IL-12. Stearylamine, a cationic lipid, showed a greater transfection efficiency compared to DOTAP-containing liposomes. The lipid:DNA ratio was 2:1 (w/w).

Alternative site of implantation affects tumor malignancy and metastatic potential in mice: its comparison to the flank model.

MC-C fibrosarcoma and B16F0 melanoma tumors were implanted intradermally in the dorsal region of the foot of mice. Tumor progression was compared to standard implantation in the flank. Although foot tumors only reached 13% (MC-C) and 25% (B16F0) of the mean volume of flank tumors, a more malignant phenotype in terms of histology and survival rate was observed in this type of tumors.

Liposome/DNA systems: correlation between association, hydrophobicity and cell viability.

Small unilamellar vesicles associated with plasmid DNA showed maximum association efficiency for a cationic mixture of egg phosphatidylcholine (EPC):1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE):di-1,2-dioleoyl-3-trimethyl ammonium propane (DOTAP) (16:8:1 molar ratio) [65%], followed by neutral lipids EPC:1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE):cholesterol (Chol) (2:2:1 molar ratio) [30%], and a polymerized formulation 1,2-bis(10,12-tricosadiynoyl)sn-glycero-3-phosphocholine (DC8,9PC):DMPE:Chol (2:2:1 molar ratio) [11%]. The hydrophobicity factor (HF) for these formulations followed the trend DC8,9PC:DMPE:CHOL < EPC:DMPE:Chol < EPC:DOPE DOTAP, and DNA association did not alter this trend. Results suggest that the higher the HF value, the more fluid the membrane and the higher the efficiency of DNA association.

Glycogen metabolism and glucose transport in experimental porphyria.

Hexachlorobenzene (HCB) is a fungicide of well-known porphyrinogenic ability, which induces an experimental porphyria that resembles human porphyria cutanea tarda (PCT) in several animal species. It has been demonstrated that high glucose ingestion prevents porphyria development, and high-fat/high-protein diets enhance HCB porphyrinogenic ability. On the contrary, a diet rich in carbohydrates reduces HCB effects.

Hexachlorobenzene impairs glucose metabolism in a rat model of porphyria cutanea tarda: a mechanistic approach.

Hexachlobenzene (HCB), one of the most persistent environmental pollutants, induces porphyria cutanea tarda (PCT). The aim of this work was to analyze the effect of HCB on some aspects of glucose metabolism, particularly those related to its neosynthesis in vivo. For this purpose, a time-course study on gluconeogenic enzymes, pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK), glucose-6-phosphatase (G-6-Pase) and on pyruvate kinase (PK), a glycolytic enzyme, was carried out.

Characterization of diacetylenic liposomes as carriers for oral vaccines.

In order to evaluate liposomes as vehicle for oral vaccines the characterization and stability of polymerized and non-polymerized liposomes were examined. Mixtures of 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3 phosphocholine) (DC8,9PC) with saturated 1,2-dimiristoyl-sn-glycero-3-phosphocholine in molar ratio 1:1 were used. Saturated and non-saturated lipids were combined to give a chemically modified membrane by UV polymerization derived from DC8,9PC.