Eder lilia Romero

National University of Quilmes | UNQ · Department of Science and Technology

Sodium alendronate (ALN) is a very hydrosoluble and poorly permeable molecule used as an antiresorptive agent and with vascular anticalcifying capacity. Loaded into targeted nanovesicles, its anti-inflammatory activity may be amplified towards extra-osseous and noncalcified target cells, such as severely irritated vascular endothelium. Here cytotox...

Chagas disease (CD) is the most important endemic parasitosis in South America and represents a great socioeconomic burden for the chronically ill and their families. The only currently available treatment against CD is based on the oral administration of benznidazole, an agent, developed in 1971, of controversial effectiveness on chronically ill p...

Research and development in health care industry is in persistence progression. To make it more patient-friendly or to get maximum benefits from it, special attention to different advanced drug delivery system (ADDS) is employed that delivers the drug at the target site and will be able to sustain/control release of drugs. ADDS should be non-toxic,...

Carotenoids are natural products regulated by the food sector, currently used as feed dyes and as antioxidants in dietary supplements and composing functional foods for human consumption. Of the nearly one thousand carotenoids described to date, only retinoids, derived from beta carotene, have the status of drug and are regulated by the pharmaceuti...

In view of the strong anti-inflammatory activity of glucocorticoids (GC) they are used in the treatment of almost all inflammatory lung diseases. In particular, inhaled GC (IGC) allow high drug concentrations to be deposited in the lung and may reduce the incidence of adverse effects associated with systemic administration. However, rapid absorptio...

Macrophages are versatile cells of the innate immune system responsible for the control and progressions of a variety of autoimmune inflammatory, infectious, and metabolic diseases and cancer. Macrophage polarization (pro-inflammatory and tissue injury M1 or anti-inflammatory, tissue repair, and proangiogenic M2) occurs in health tissues and in dis...

Archaea are microorganisms more closely related to eukaryotes than bacteria. Almost 50 years after being defined as a new domain of life on earth, new species continue to be discovered and their phylogeny organized. The study of the relationship between their genetics and metabolism and some of their extreme habitats has even positioned them as a m...

This study aimed to determine the damage mechanisms caused by naturally targeted nanoarchaeosomes made of diether lipids from Halorubrum tebenquichense loaded with curcumin (CUR, nATC), which mediated photodynamic therapy (PDT) on A549 cells and on THP-1-macrophages, two cell types found in airway cancers. The effect of nATC- PDT on vessels modeled...

Background: The wide spectrum of antitumoral mechanisms of imiquimod (IMQ), made it a good candidate for topical therapy of melanoma. However, physicochemical properties make IMQ formulation a difficult task. Solubility and skin penetration of IMQ are increased when loaded into ultradeformable nanovesicles. Objective: Survey the in vitro anti-me...

Nanoarchaeosomes are roughly smaller than 600-nm-diameter vesicles, having a mono- or oligolamellar monolayer or a bilayer membrane, made of pure archaeolipids, or in combination with other amphipathic molecules. They share morphology with liposomes but exhibit different properties, from their lipid stereoisomerism, their reactivity in front to che...

Bacterioruberin (BR) is a dipolar C50 isoprenoid with 13 conjugated double bonds and four terminals hydroxyl groups produced by most members of the Haloferacaceae family of halophilic archaea. BR is a natural antioxidant with antimicrobial, antiviral, anticancer and antihaemolytic activity, but its chemical lability, poor water solubility and low b...

Psoriasis (Ps) is a multifactorial autoimmune skin disease, where oxidative stress plays a key role in promoting a vicious producing cycle between keratinocytes and immune cells. Vitamin D3 (VD3) regulates the differentiation, apoptosis, and proliferation of keratinocytes, also displaying antioxidant and anti-inflammatory activities. Previous attem...

Background Pseudomonas aeruginosa biofilms in the respiratory tract of patients with an excessive inflammatory context are difficult to eradicate. New medicines that simultaneously target biofilms and inflammation should be developed. Hypothesis Co-delivery of Thymus vulgaris essential oil (EOT) and tobramycin (TB) by nanostructured archaeolipids...

Archaebacterias are considered a unique source of novel biomaterials of interest for nanomedicine. In this perspective, the effects of nanoarchaeosomes (ARC), which are nanovesicles prepared from polar lipids extracted from the extreme halophilic Halorubrum tebenquinchense, on human umbilical vein endothelial cells (HUVEC) were investigated in phys...

The anti-inflammatory, antifibrotic and antimicrobial activities of curcumin (CUR) are missed because of its low solubility in aqueous media, low bioavailability, and structural lability upon oral intake. Soft nanoparticles such as nanoliposomes are not efficient as CUR carriers, since crystalline CUR is expelled from them to physiological media. N...

Introduction Autophagy is a critical housekeeping pathway to remove toxic protein aggregates, damaged organelles, providing cells with bioenergetic substrates needed to survive under adverse conditions. Since altered autophagy is associated to diverse diseases, its pharmacological modulation is considered of therapeutic interest. Nanomedicines may...

Nanoarchaeosomes are non-hydrolysable nanovesicles made of archaeolipids, naturally functionalised with ligand for scavenger receptor class 1. We hypothesized that nitrogenate bisphosphonate alendronate (ALN) loaded nanoarchaeosomes (nanoarchaeosomes(ALN)) may constitute more efficient macrophage targeted apoptotic inducers than ALN loaded nanolipo...

img src=” https://s3.amazonaws.com/production.scholastica/article/13493/large/prnano_482020_ga.jpg?1593185863”> Many infections affecting animals enter across mucosa, needing of secretory immunity to reject the disease; protection against some pathogens must be early, fast, and specifically elicited, while from others must be wide enough to fight a...

Oral administration of antioxidant and anti-inflammatory drugs have the potential to improve the current therapy of inflammatory bowel disease. Success of oral treatments, however, depends on the capacity of drugs to remain structurally stable along the gastrointestinal tract, and on the feasibility of accessing the target cells. Delivering anti-in...

Azithromycin (AZ) is a broad-spectrum antibiotic with anti-inflammatory and anti-quorum sensing activity against biofilm forming bacteria such as Pseudomonas aeruginosa (Pa). AZ administered by oral or parenteral routes however, neither efficiently access nor remain in therapeutic doses inside pulmonary biofilm depths. Instead, inhaled nanocarriers...

Neglected tropical diseases (NTDs) are endemic to tropical and subtropical regions in Latin America, Africa and parts of Asia, representing a global public health problem. Despite affecting more than one billion people worldwide, the treatments for these diseases are highly toxic or even nonexistent, and it is usually necessary to treat the symptom...

Oxidative stress plays an essential role in the pathogenesis and progression of inflammatory bowel disease. Co-administration of antioxidants and anti-inflammatory drugs has shown clinical benefits. Due to its significant reactive oxygen species (ROS) scavenging ability, great interest has been focused on superoxide dismutase (SOD) for therapeutic...

Background: Thymus vulgaris essential oil (T) could be an alternative to classical antibiotics against bacterial biofilms, which show increased tolerance to antibiotics and host defence systems and contribute to the persistence of chronic bacterial infections. Hypothesis: A nanovesicular formulation of T may chemically protect the structure and rel...

Hyperhalophilic archaebacteria exclusively produce sn2,3 diphytanylglycerol diether archaeolipids, unique structures absent in bacteria and eukaryotes. Nanovesicles made of archaeolipids known as nanoarchaeosomes (nanoARC), possess highly stable bilayers, some of them displaying specific targeting ability. Here we hypothesize that nanoARC made from...

Development of needle and pain free noninvasive immunization procedures is a top priority for public health agencies. In this work the topical adjuvant activity of the immunomodulator imiquimod (IMQ) carried by ultradeformable archaeosomes (UDA2) (nanovesicles containing sn-2,3 ether linked phytanyl saturated archaeolipids) was surveyed and compare...

The adequate formulation of topical vehicles to treat skin diseases is particularly complex. A desirable formulation should enhance the accumulation of the active drugs in the target tissue (the skin), while avoiding the penetration enhancement to be so large that the drugs reach the systemic circulation in toxic amounts. We have evaluated the tran...

Snake envenoming is a partly solved threat that constitutes a major concern for the public health of tropical and subtropical countries. Antisera based in polyclonal heterologous antibodies save the victims’ life, but often are not efficient enough to avoid the amputation of the affected limbs. In this strategic approach we propose to complement th...

The impact of lipid-based nanomedicines on living beings widely differs from that caused by non-intentional exposition of metallic, metallic oxides, or carbon-based inhaled nanomaterials. The scarce data gathered on nanotoxicity of lipid-based nanomedicines is mostly related to intravenous and inhalation routes. This last is also the most important...

In this work, a NE-U22 vibrating mesh Omron nebulizer was used to deliver Lissamine™ rhodamine B 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine triethylammonium salt (Rh-PE) and 8-Hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS)/ p-xylene-bis-pyridinium bromide (DPX) double labelled macrophage-targeted pH-sensitive archaeosomes (ApH,...

Aim: Develop nanoparticulate agents for oral targeted delivery of dexamethasone (Dex) to macrophages of inflamed mucosa. Materials & methods: Solid archaeolipid nanoparticles (SAN-Dex) (compritol/Halorubrum tebenquichense polar archaeolipids/soybean phosphatidylcholine/Tween-80 4; 0.9; 0.3; 3% w/w) loaded with Dex were prepared. Their mucopenetr...

Ultradeformable archaeosomes (UDA) are nanovesicles made of total polar archaeolipids (TPA) from the archaea Halorubrum tebenquichense, soybean phosphatidylcholine and sodium cholate (3:3:1 w/w). Fresh dispersions of UDA including different type of antigens are acknowledged as efficient topical vaccination agents. UDA dispersions however, if manufa...

Aim: To increase the subcellular delivery of dexamethasone phosphate (DP) and stability to nebulization stress, pH-sensitive nanoliposomes (LpH) exhibiting archaeolipids, acting as ligands for scavenger receptors (pH-sensitive archaeosomes [ApH]), were prepared. Materials & methods: The anti-inflammatory effect of 0.18 mg DP/mg total lipid, 100-...

Total antigens from Leishmania braziliensis promastigotes, solubilized with sodium cholate (dsLp), were formulated within ultradeformable nanovesicles (dsLp-ultradeformable archaeosomes, (dsLp-UDA), and dsLp-ultradeformable liposomes (dsLp-UDL)) and topically administered to Balb/c mice. Ultradeformable nanovesicles can penetrate the intact stratum...

Besides native dendrimer nanoparticles, those with advanced surface modifications are tested for topical use in skin diseases, yet at a preclinical level. These nanoparticles include core-multishell (CMS) nanotransporters which are dendrimers covered by a lipophilic inner shell and a hydrophilic/amphiphilic outer shell. CMS nanotransporters are loa...

Leishmaniasis and Chagas disease, the most important protozoan infections in Latin America and the Caribbean, are caused by intracellular parasites. Treatments of Chagas disease and cutaneous leishmaniasis have limitations including toxicity, variable efficacy, requirements for parenteral administration, and lengthy treatment regimens. Despite prog...

Deformability is a key property of drug carriers used to increase the mass penetration across the skin without disrupting the lipid barrier. Highly deformable vesicles proved to be more effective than conventional liposomes in delivering drugs into and across the mammalian skin upon topical non occlusive application. In the past five years, highly...

Ultradeformable vesicles are highly deformable (elastic/flexible) liposomes made of phospholipids plus highly mobile hydrophilic detergents capable of penetrating the intact skin across the stratum corneum and reaching the viable epidermis. Ultradeformable vesicles are more effective than conventional liposomes in delivering drugs into and across t...

Aiming to improve the topical delivery of AmB to treat cutaneous fungal infections and leishmaniasis, ultradeformable liposomes containing amphotericin B (AmB-UDL) were prepared, and structural and functional characterized. The effect of different edge activators, phospholipid and AmB concentration, and phospholipid to edge activator ratio on lipos...

Dendritic nanoparticles have been developed with auspicious propertieslike high loading capacity for guest molecules, low polydispersity and tunable end groups. Demonstrating increased cellular uptake, and bypassed efflux transporters,dendritic nanoparticles may offer new treatment options for therapy-resistant diseases. New core-shell architecture...

Chagas disease is a neglected parasitic infection caused by the protozoan Trypanosoma cruzi. After a mostly clinically silent acute phase, the disease becomes a lifelong chronic condition that can lead to chronic heart failure and thromboembolic phenomena followed by sudden death. Antichagasic treatment is only effective in the acute phase but fail...

In this work, the in vitro anti-Leishmania activity of photodynamic liposomes made of soybean phosphatidylcholine, sodium cholate, total polar archaeolipids (TPAs) extracted from the hyperhalophile archaea Halorubrum tebenquichense and the photosensitizer zinc phthalocyanine (ZnPcAL) was compared to that of ultradeformable photodynamic liposomes la...

New therapies are urgently needed against melanoma, one of the most aggressive tumors. Melanoma cells are resistant to the antifolate methotrexate (MTX), since MTX is taken up by the folate receptor-α (FRα), sequestered in melanosomes and exported out of the cell. The bisphosphonate zoledronic acid (ZOL) is active in several non-skeletal tumors; ho...

The ultradeformable archaeosomes (UDA, made of total polar archaeolipids (TPA) extracted from the extreme halophile archaea Halorubrum tebenquichense:soybean phosphatidylcholine (SPC):sodium cholate (NaChol), 3:3:1 w:w), are promising topical adjuvants showing high deformability, an essential property for intact skin penetration up to the viable ep...

Several nanotechnological solutions for mucosal immunization have been proposed, such as nanoparticles, liposomes, solid lipidic particles, micelles, and surfactant vesicles. In recent years, surfactant vesicles have gained increasing scientific attention as an alternative potential drug delivery system to the conventional liposome. This type of ve...

With the aim of improving the antioxidant activity of polyphenols from blueberries (Vaccinium myrtillus) on skin targets after topical application, ethanolic extracts from three blueberry varieties (named Millenia, O'Neal, and Blue Crisp) were loaded into ultradeformable liposomes. These nanocarriers are known to be capable of penetrating through t...

Vesicles that are specifically designed to overcome the stratum corneum barrier in intact skin provide an efficient transdermal (systemic or local) drug delivery system. They can be classified into two main groups according to the mechanisms underlying their skin interaction. The first group comprises those possessing highly deformable bilayers, ac...

Fungal infections can attack epithelial tissues and, according to the immunological state of the patient, some of them invade deeper organs, becoming seriously life compromising. Besides, bloodstream and local infections associated with intravascular devices constitute a significant problem associated with increased mortality. Topical therapy is de...

Archaeosomes (ARC), vesicles made from lipids extracted from Archaea, display strong adjuvant properties. In this study, we evaluated the ability of the highly stable ARC formulated from total polar lipids of a new Halorubrum tebenquichense strain found in Argentinean Patagonia, to act as adjuvant for soluble parasite antigens in developing prophyl...

The use of photodynamic therapy (PDT) against cutaneous leishmaniasis (CL) based on chloroaluminum phthalocyanine (ClAlPc) is a promissory alternative therapy. The main purpose of this article was to assess the internalization and in vitro phototoxic activities of ClAlPc encapsulated in ultradeformable liposomes (UDL-ClAlPc) in Leishmania parasites...

Background The controlled introduction of covalent linkages between dendrimer building blocks leads to polymers of higher architectural order known as tecto-dendrimers. Because of the few simple steps involved in their synthesis, tecto-dendrimers could expand the portfolio of structures beyond commercial dendrimers, due to the absence of synthetic...

Background Molecules taken up by olfactory and trigeminal nerve neurons directly access the brain by the nose-to-brain pathway. In situ-forming mucoadhesive gels would increase the residence time of intranasal material, favoring the nose-to-brain delivery. In this first approach, brain radioactivity after intranasal administration of ³²P-small inte...

Unlabelled: Ultradeformable archaeosomes (UDA) are vesicles made of soybean phosphatidylcholine (SPC), sodium cholate (NaChol) and polar lipids from Halorubrum tebenquichense (3:1:3 wt/wt). Although ultradeformable liposomes (UDL, made of SPC and NaChol at 6:1 wt/wt) and UDA were neither captured nor caused cytotoxicity on keratinocytes, UDA was a...

Background Gene silencing using small interfering RNA (siRNA) is a promising new therapeutic approach for glioblastoma. The endocytic uptake and delivery of siRNA to intracellular compartments could be enhanced by complexation with polyamidoamine dendrimers. In the present work, the uptake mechanisms and intracellular traffic of siRNA/generation 7...

Mucosal (and in minor extent transcutanous) stimulation can induce local or distant mucosa secretory IgA. Liposomes and other vesicles as mucosal and transcutaneous adjuvants are attractive alternatives to parenteral vaccination. Liposomes can be massively produced under good manufacturing practices and stored for long periods, at high antigen/vesi...

Curcumin is a polyphenol obtained from the plant Curcuma longa (called turmeric) that displays several pharmacological activities, including anti-inflammatory, antioxidant, antimicrobial and antitumoral activity, but clinical use has been limited by its poor solubility in water and, consequently, minimal systemic bioavailability. We have therefore...

Selecting antimicrobials as a function of their chemical structure is a classical paradigm that was challenged by the advent of nanomedicines. Drugs carried in nanoparticles can be delivered into intracellular compartments in cells from selected tissues, independently of free drug’s pharmacokinetics and pharmacodynamics. Inflammation associated to...

The archaeolipids (lipids extracted from archaebacterias) are non saponificable molecules that form self sealed mono or bilayers (archaeosomes-ARC). Different to liposomes with bilayers made of conventional glycerophospholipids, the bilayer of ARC posses a higher structural resistance to physico chemical and enzymatic degradation and surface hydrop...

Introducción. Los liposomas son sistemas supramoleculares autoensamblables preparados ad hoc, compuestos de fosfolípidos y colesterol, diseñados para transporte de fármacos o radionucleidos. El 99mTc es el radionucleido más empleado por sus propiedades físicas apropiadas para la adquisición de imágenes y estudios en pacientes en el área de medicina...

Introducción. Los liposomas son sistemas supramoleculares autoensamblables preparados ad hoc, compuestos de fosfolípidos y colesterol, diseñados para transporte de fármacos o radionucleidos. El 99mTc es el radionucleido más empleado por sus propiedades físicas apropiadas para la adquisición de imágenes y estudios en pacientes en el área de medicina...

Being independent of artificial power sources, self administered sunlight triggered photodynamic therapy could be a suitable alternative treatment for cutaneous leishmaniasis, that avoids the need for injectables and the toxic side effects of pentavalent antimonials. In this work we have determined the in vitro leishmanicidal activity of sunlight t...

Over several thousand years, the flagellated Trypanosome cruzi-causative agent of Chagas disease-developed a complex life cycle between the reduviidae vectors and its human hosts. Due to their silent and hidden location, the intracellular amastigotes are mainly responsible for the nearly 50,000 annual deaths caused by the chronic chagasic cardiomyo...

Archaeosomes (ARC), vesicles prepared from total polar lipids (TPL) extracted from selected genera and species from the Archaea domain, elicit both antibody and cell-mediated immunity to the entrapped antigen, as well as efficient cross priming of exogenous antigens, evoking a profound memory response. Screening for unexplored Archaea genus as new...

We have screened the formation of complexes between ethylendiamine (EDA) core polyamidoamine (PAMAM) dendrimers (D) and a short interfering RNA (siRNA) as a function of three variables: the ionic strength of the medium (lacking or containing 150 mM NaCl), the D generation (G4, G5, G6 and G7) and the N/P ratio (nitrogen amines in D/phosphate in siRN...

Although freeze-drying is an ordinarily used technique to dehydrate conventional liposomes, we have found that ultradeformable liposomes (UDLs) suffered irreversible aggregation when rehydrated upon freeze-drying (99.4% water elimination), even in high sugar content (4/1 sucrose/lipid mass ratio). When dehydrated by speed vac and vacuum drying, two...

Cytotoxicity of sulfadiazine (SDZ) complexed with PAMAM dendrimers of fourth generation (SDZ-DG4) determined by MTT assay and LDH leakage, was reduced on covered (with mucins) but not on nude (without mucins) Caco-2 cell line. SDZ-DG4 adsorption and uptake on nude and covered Caco-2 cells, determined by flow cytometry and fluorescence confocal micr...

Leishmania amastigotes live inside resident macrophages in different anatomic sites. Their hidden location is responsible for impairing the accession of therapeutic drugs. Drug delivery systems (DDSs) should allow the adverse effects caused by problematic routes of administration to be avoided as well as enhancing the antileishmanial activity and r...

Hydrophobic ([tetrakis(2,4-dimetil-3-pentyloxi)-phthalocyaninate]zinc(II)) (ZnPc) and hydrophilic ([tetrakis(N,N,N-trimethylammoniumetoxi)-phthalocyaninate]zinc(II) tetraiodide) (ZnPcMet) phthalocyanines were synthesized and loaded in ultradeformable liposomes (UDL) of soybean phosphatidylcholine and sodium cholate (6:1, w/w, ratio), resulting 100...

The high doses of sulfadiazine (SDZ), used in synergistic combination with pyrimethamine, are mainly responsible for severe side effects and discontinuation of toxoplasmosis treatments. In the search for new strategies that improve the efficacy of treatments with reduced doses of SDZ, we have determined the performance of cationic G4 (DG4) and anio...

In spite of its widespread use, benznidazole's (BNZ) toxicity and low efficacy remains as major drawbacks that impair successful treatments against Chagas disease. Previously, attempting to increase the selectivity and reduce its toxicity on infected tissues, multilamellar liposomes (MLV) composed of hydrogenated soybean phosphatidylcholine (HSPC):...

In this work, the hydrophilic, low molecular weight and trypanocidal drug etanidazole (ETZ) was loaded in pH-sensitive liposomes (L-ETZ). Liposomes were made of dioleoyl-phosphatidylethanolamine: cholesteryl hemisuccinate (DOPE:CHEMS, 6:4, mol:mol), of 380 nm size at 14% ETZ/total lipid (w/w) ratio. To follow their uptake and intracellular fate by...

With the aim of investigating if delivery of benznidazole (BNZ) to liver could be increased by incorporating the drug in multilamellar liposomes, single bolus of free BNZ or liposomal BNZ formulations (MLV-BNZ) composed of HSPC:DSPG:Chol 2:1:2 (mol/mol/mol) at 0.7% (w/w) drug/total lipid ratio, were injected by intramuscular (i.m.), subcutaneous (s...

We investigated the in vitro action of an hydrosoluble 2-nitroimidazole, Etanidazole (EZL), against Trypanosoma cruzi, the etiologic agent of Chagas disease. EZL displayed lethal activity against isolated trypomastigotes as well as amastigotes of T. cruzi (RA strain) growing in Vero cells or J774 macrophages, without affecting host cell viability....

We investigated the in vitro action of an hydrosoluble 2-nitroimidazole, Etanidazole (EZL), against Trypanosoma cruzi , the etiologic agent of Chagas disease. EZL displayed lethal activity against isolated trypomastigotes as well as amastigotes of T. cruzi (RA strain) growing in Vero cells or J774 macrophages, without affecting host cell viability....

In this work, an isocratic high-performance liquid chromatographic method for quantitation of liposomal benznidazole (BNZ) in biological tissues is presented. The method comprises protein precipitation together with an efficient extraction of bulk or liposomal BNZ with acetonitrile-dimethylsulfoxide (1:1, v/v) at a 2:1 (extraction solvent-tissue ma...

The purpose of this study was to find a multilamellar liposomal formulation for the antichagasic drug Benznidazole (BNZ). Different lipid matrices and organic solvents for BNZ were tested in order to obtain the liposomes with the highest g BNZ/100 g total lipid (D/TL) ratio. The best lipid matrices resulted from hydrogenated phosphatidylcholine fro...

The search for transfection vectors which combine efficacy, biosafety and low immunogenocity, has driven the development of lipid vectors. These vectors, be it liposomes or lipoplex, transport DNA or RNA to adjacences of target cells, and deliver them for posterior transfection, which is accomplish with a relatively low efficiency, as compared to v...

The search for transfection vectors which combine efficacy, biosafety and low immunogenocity, has driven the development of lipid vectors. These vectors, be it liposomes or lipoplex, transport DNA or RNA to adjacences of target cells, and deliver them for posterior transfection, which is accomplish with a relatively low efficiency, as compared to v...

By means of recording a simple serie of merocyanine 540 spectra, we present a method to calculate the value proportional to co-operative unit size of membranes (n). Our calculations, applied to different liposomal samples processed in the presence or absence of sugars, in high or low ionic strength showed two main results. First, that any temperatu...

Phospholipids are capable of spontaneous self-assembling, a remarkable differential property if compared with the rest of biological molecules. By their means it is relatively easy to generate extremely stable sealed structures, with controlled shape, size and packing, known as liposomes. In this article, we review the use of liposomes to improve t...

In this contribution we summarize our observations over a period of nearly two decennia on the role of hepatocytes in the hepatic clearance of intravenously administered liposomes. We demonstrate that, although size is an important parameter, it is not decisive in determining access of liposomes to the hepatocytes. Also lipid composition is an impo...

Liposomes of 400 nm in diameter can cross the 100-nm fenestrations in the endothelium of the hepatic sinusoid, provided they contain phosphatidylserine (PS) but not phosphatidylglycerol (PG) [Daemen et al. (1997) Hepatology 26, 416]. We present evidence indicating that (i) the PS effect does not involve a pharmacological action of this lipid on the...

Our results show that if the 2-thiobarbituric acid concentration is decreased, its co-precipitation with the chromophore is diminished. Subsequent running of this reaction mixture by high-performance liquid chromatography still allows measurement of Neu-5-Ac in the picomole order, with a substantial time and reactive saving, as compared with the or...

A discussion is presented on the soil solution solute content in the unsaturated unsaturated zone based on data obtained from weekly samples using porous ceramic and PTFE suction in the period February-May 1997. We examine the interaction between the soil solution and the porous materials for several time dependent values (temperature, conductivity...

Geostatistical techniques were applied to the study of the soil moisture distribution measured with TDR probes. The sampling took place in a experimentatal field planted with Stevia rebaudiana Bertoni under two different water regimes, (humid one and dry). Results show that, in the first crop stage, which is that of establishment of the crop in the...

autoensamblables. Palabras clave: liposomas, lipoplex, lípidos catiónicos, encapsulación, terapia génica, transfección Abstract Lipid vectors. New strategies for gene therapy. Phospholipids are capable of spontaneous self- assembling, a remarkable differential property if compared with the rest of biological molecules. By their means it is relative...