|
|
|
Registros recuperados: 24 | |
|
|
Volpedo,Greta; Costa,Lourena; Ryan,Nathan; Halsey,Gregory; Satoskar,Abhay; Oghumu,Steve. |
Abstract Neglected Tropical Diseases (NTDs) comprise of a group of seventeen infectious conditions endemic in many developing countries. Among these diseases are three of protozoan origin, namely leishmaniasis, Chagas disease, and African trypanosomiasis, caused by the parasites Leishmania spp., Trypanosoma cruzi, and Trypanosoma brucei respectively. These diseases have their own unique challenges which are associated with the development of effective prevention and treatment methods. Collectively, these parasitic diseases cause more deaths worldwide than all other NTDs combined. Moreover, many current therapies for these diseases are limited in their efficacy, possessing harmful or potentially fatal side effects at therapeutic doses. It is therefore... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Leishmaniasis; Chagas; Trypanosomiasis; Nanoparticles; Liposomes; Nanotubes; Nanodiscs; Micelles. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992019000100201 |
| |
|
| |
|
|
CAMILO,Cicera J.; LEITE,Débora O. D.; SILVA,Angelo R. A. e; MENEZES,Irwin R. A.; COUTINHO,Henrique D. M.; COSTA,José G. M. da. |
ABSTRACT Liposomes and niosomes are currently the most studied lipid vesicles in the nanomedicine field. The system formed by a phospholipid bilayer in aqueous medium allows these vesicles to carry both hydrophilic and lipophilic compounds, providing an increase in solubility of drugs already used in conventional therapy. The focus on the development of these vesicles should be directed to determining the ideal composition, with low toxicity, biocompatibility and which remains stable for long periods. These characteristics are related to the components used for formulation and the substances that will be encapsulated. Another important point relates to the methods used during formulation, which are important in determining the type of vesicle formed,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Components; Formulation; Liposomes; Nanomedicine; Niosomes. |
Ano: 2020 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2020000200339 |
| |
|
| |
|
|
CIRINO,LORENA M.D.; VERGNE,DAVIANE M.C.; SANTANA,PATRÍCIA F.; ALMEIDA,ENRIK DE; COSTA,LUIZ P. DA; ALBUQUERQUE-JÚNIOR,RICARDO L.C. DE; LIMA-VERDE,ISABEL B.; PADILHA,FRANCINE F.; CARDOSO,JULIANA C.. |
ABSTRACT The objective of this work was to study the reduction in the capsaicin toxicity by encapsulation in liposomes. Capsaicin was extracted from peppers and characterized with high performance liquid chromatography (HPLC). We determined the zeta potential, polydispersivity index (PdI) and vesicle size of liposomes. Wistar rats were submitted to intravesical instillation of liposomes (LIP), capsaicin (CAP) or liposomes with capsaicin (CAPLIP). After 24 hours, bladders were removed for histological analysis. Vesicle size ranged from 68 to 105 nm with PdI smaller than 0.2 and zeta potential around -30 mV. The vesicles maintained stability over the 14-day study. The histological analysis of the CAP group showed intense inflammation in almost all bladder... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Capsaicin; Liposomes; Urinary incontinence; Intravesical administration. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000401539 |
| |
|
|
BORIN,DIEGO B.; MEZZOMO,NATHANA J.; VAUCHER,RODRIGO A.; CARMO,GUILHERME DO; RODRIGUES JUNIOR,LUIZ C.; SULCZEWSKI,FERNANDO B.; SCHWERTZ,CLAITON I.; MENDES,RICARDO E.; DAMIANI,ADRIANI P.; ANDRADE,VANESSA M. DE; RECH,VIRGÍNIA C.; BOECK,CARINA R.. |
ABSTRACT Creatine acts intracellularly as energy buffer and storage, demonstrating protective effects in animal models of neurodegenerative diseases. However, its permeability throught blood-brain barrier (BBB) is reduced. The aim of the present study was developing a carrier to facilitate the delivery of creatine to the central nervous system. Creatine nanoliposomes were produced, characterized and assayed in models of toxicity in vitro and in vivo. Particles showed negative zeta potential (-12,5 mV), polydispersity index 0.237 and medium-size of 105 nm, which was confirmed by transmission electron microscopy (TEM) images. Toxicity assay in vitro was evaluated with blank liposomes (no drug) or creatine nanoliposomes at concentrations of 0.02 and 0.2... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nanocarrier; Neurodegenerative diseases; Nanotechnology; Liposomes. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652018000502317 |
| |
|
| |
|
|
Alves,Andrea Catão; Gontijo,Cristiano Machado; Oliveira,Mônica Cristina; Diniz,Simone Odília Fernandes; Oliveira,Flávia Márcia; Cardoso,Valbert Nascimento; Ramaldes,Gilson Andrade. |
The oral administration of proteic antigens, like ovalbumin, may result in the induction of oral tolerance or immunization. The aim of this work was to label a protein antigen with 99mTechnetium, encapsulate it in liposomes and investigate its absorption and tissue distribution after oral administration in mice. Ovalbumin was labeled with 99mTechnetium and encapsulated in small unilamellar vesicles. 99mTc-OVA encapsulated or not in liposomes was administrated to mice that were sacrificed after different times. The radioactivity was measured in various organs of the animals. Differences concerning the biodistribution of 99mTc-OVA were noticed. The technique may represent alternatives for the induction of immunization or oral tolerance. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Liposomes; Oral absorption; Mucosal delivery; Proteins; Nanotechnology. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000700035 |
| |
|
| |
|
|
Araújo,R.V.S.; Melo-Júnior,M.R.; Beltrão,E.I.C.; Mello,L.A.; Iacomini,M.; Carneiro-Leão,A.M.A.; Carvalho Jr,L.B.; Santos-Magalhães,N.S.. |
The antischistosomal activity of the sulfated polysaccharide α-D-glucan (Glu.SO4) extracted from Ramalina celastri was evaluated after encapsulation into liposomes (Glu.SO4-LIPO) in Schistosoma mansoni-infected mice. The effect of treatment with Glu.SO4 and Glu.SO4-LIPO (10 mg/kg) on egg elimination, worm burden and hepatic granuloma formation was assessed using female albino Swiss mice, 35-40 days of age, weighing 25 ± 2 g, infected with 150 cercariae/animal (Biomphalaria glabrata, BH strain). Four groups (N = 10) were studied, two controls (empty liposomes and NaCl) and two treated groups (Glu.SO4-LIPO and Glu.SO4) using a single dose. Parasitological analysis revealed that Glu.SO4-LIPO was as efficient as Glu.SO4 in reducing egg elimination and worm... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Polysaccharide; Α-D-glucan; Ramalina celastri; Liposomes; Schistosoma mansoni; Lectin histochemistry. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000400007 |
| |
|
|
Yuldasheva,L.N.; Carvalho,E.B.; Catanho,M.-T.J.A.; Krasilnikov,O.V.. |
Plants used in traditional medicine are rich sources of hemolysins and cytolysins, which are potential bactericidal and anticancer drugs. The present study demonstrates for the first time the presence of a hemolysin in the leaves of Passiflora quadrangularis L. This hemolysin is heat stable, resistant to trypsin treatment, has the capacity to froth, and acts very rapidly. The hemolysin activity is dose-dependent, with a slope greater than 1 in a double-logarithmic plot. Polyethylene glycols of high molecular weight were able to reduce the rate of hemolysis, while liposomes containing cholesterol completely inhibited it. In contrast, liposomes containing phosphatidylcholine were ineffective. The Passiflora hemolysin markedly increased the conductance of... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Passiflora quadrangularis; Leaf extract; Liposomes; Bilayer permeation; Hemolysin; Membrane cholesterol. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000700009 |
| |
|
|
Frézard,F.; Michalick,M.S.M.; Soares,C.F.; Demicheli,C.. |
The antimonial drug, meglumine antimoniate, was successfully encapsulated in dehydration-rehydration vesicles and in freeze-dried empty liposomes (FDELs). High encapsulation efficiencies (from 28 to 58%) and low weight ratios of lipids to encapsulated antimony (from 1:0.15 to 1:0.3) were achieved. These formulations, contrary to those obtained by conventional methods, can be stored as intermediate lyophilized forms and reconstituted just before use. The efficacy of FDEL-encapsulated meglumine antimoniate was evaluated in hamsters experimentally infected with Leishmania chagasi. A significant reduction of liver parasite burdens was observed in animals treated with this preparation, when compared to control animals treated with empty liposomes. In contrast,... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Liposomes; Glucantime; Meglumine antimoniate; Leishmaniasis; Encapsulation. |
Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000700016 |
| |
|
| |
|
|
The possibility of producing neutralizing antibodies against the lethal effects of scorpion toxins was evaluated in the mouse model by immunization with an immunogen devoid of toxicity. A toxic fraction (5 mg) from the venom of the scorpion Tityus serrulatus was entrapped in sphingomyelin-cholesterol liposomes. The liposomes were treated for 1 h at 37oC with a 1% (w/w) trypsin solution in 0.2 M sodium carbonate buffer, pH 8.3. This treatment led to a strong reduction in venom toxicity. Immunization was performed as follows: mice were injected sc with 20 µg of the liposome-entrapped toxic fraction on days 1 and 21 and a final injection (20 µg) was administered ip on day 36. After injection of the immunogen, all mice developed an IgG response which was shown... |
|
Palavras-chave: Liposomes; Neutralizing antibodies; Tityus serrulatus; Immunization; Toxins. |
Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000700010 |
| |
|
|
Carvalho Júnior,A.D.; Vieira,F.P.; De Melo,V.J.; Lopes,M.T.P.; Silveira,J.N.; Ramaldes,G.A.; Garnier-Suillerot,A.; Pereira-Maia,E.C.; De Oliveira,M.C.. |
We encapsulated cisplatin into stealth pH-sensitive liposomes and studied their stability, cytotoxicity and accumulation in a human small-cell lung carcinoma cell line (GLC4) and its resistant subline (GLC4/CDDP). Since reduced cellular drug accumulation has been shown to be the main mechanism responsible for resistance in the GLC4/CDDP subline, we evaluated the ability of this new delivery system to improve cellular uptake. The liposomes were composed of dioleoylphosphatidylethanolamine (DOPE), cholesteryl hemisuccinate (CHEMS), and distearoylphosphatidylethanolamine-polyethyleneglycol 2000 (DSPE-PEG2000) and were characterized by determining the encapsulation percentage as a function of lipid concentration. Among the different formulations,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cisplatin; Liposomes; Encapsulation; Cytotoxicity. |
Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007000800017 |
| |
|
|
Schettini,D.A.; Costa Val,A.P.; Souza,L.F.; Demicheli,C.; Rocha,O.G.F.; Melo,M.N.; Michalick,M.S.M.; Frézard,F.. |
The achievement of complete cure in dogs with visceral leishmaniasis is currently a great challenge, since dogs are the main reservoir for the transmission of visceral leishmaniasis to humans and they respond poorly to conventional treatment with pentavalent antimonials. In order to improve the efficacy of treatment, we developed a novel formulation for meglumine antimoniate based on the encapsulation of this drug in freeze-dried liposomes (LMA). The aim of the present study was to evaluate the biodistribution of antimony (Sb) in dogs following a single intravenous bolus injection of LMA. Four healthy male mongrel dogs received LMA at 3.8 mg Sb/kg body weight and were sacrificed 3, 48 and 96 h and 7 days later. Antimony was determined in the blood, liver,... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Liposomes; Meglumine antimoniate; Biodistribution; Leishmaniasis; Dogs. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000200015 |
| |
|
| |
|
|
El-Nakeeb,Moustafa A; Abou-Shleib,Hamida M; Khalil,Amal M; Omar,Hoda G; El-Halfawy,Omar M. |
Several antihistaminics possess antibacterial activity against a broad spectrum of bacteria. However, the exact mechanism of such activity was unclear. Hence, the aim of this study is to investigate their mechanism of antibacterial activity especially their effect upon the permeability of the bacterial cytoplasmic membrane. The effects of azelastine, cetirizine, cyproheptadine and diphenhydramine were studied using Gram-positive and Gram-negative multiresistant clinical isolates. Leakage of 260 and 280 nm UV-absorbing materials was detected upon treatment with the tested antihistaminics; indicative of membrane alteration. Using an artificial membrane model, cholesterol-free negatively-charged unilamellar liposomes, confirmed the effect of antihistaminics... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antihistaminics; Azelastine; Bacteria; Cytoplasmic membrane; Liposomes; Permeability alteration. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000300019 |
| |
|
|
Torres,Ieda Maria Sapateiro; Bento,Etiene Barbosa; Almeida,Larissa da Cunha; Sá,Luisa Zaiden Carvalho Martins de; Lima,Eliana Martins. |
Pseudomonas aeruginosa is an opportunistic microorganism with the ability to respond to a wide variety of environmental changes, exhibiting a high intrinsic resistance to a number of antimicrobial agents. This low susceptibility to antimicrobial substances is primarily due to the low permeability of its outer membrane, efflux mechanisms and the synthesis of enzymes that promote the degradation of these drugs. Cephalosporins, particularty ceftazidime and cefepime are effective against P. aeruginosa, however, its increasing resistance has limited the usage of these antibiotics. Encapsulating antimicrobial drugs into unilamellar liposomes is an approach that has been investigated in order to overcome microorganism resistance. In this study, antimicrobial... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pseudomonas aeruginosa; Liposomes; Cephalosporins. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822012000300020 |
| |
|
| |
Registros recuperados: 24 | |
|
|
|