Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Int J Mol Sci ; 21(15)2020 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-32707876

RESUMEN

In this work, we aimed to develop liposomal nanocomposites containing citric-acid-coated iron oxide magnetic nanoparticles (CMNPs) for dual magneto-photothermal cancer therapy induced by alternating magnetic field (AMF) and near-infrared (NIR) lasers. Toward this end, CMNPs were encapsulated in cationic liposomes to form nano-sized magnetic liposomes (MLs) for simultaneous magnetic hyperthermia (MH) in the presence of AMF and photothermia (PT) induced by NIR laser exposure, which amplified the heating efficiency for dual-mode cancer cell killing and tumor therapy. Since the heating capability is directly related to the amount of entrapped CMNPs in MLs, while the liposome size is important to allow internalization by cancer cells, response surface methodology was utilized to optimize the preparation of MLs by simultaneously maximizing the encapsulation efficiency (EE) of CMNPs in MLs and minimizing the size of MLs. The experimental design was performed based on the central composite rotatable design. The accuracy of the model was verified from the validation experiments, providing a simple and effective method for fabricating the best MLs, with an EE of 87% and liposome size of 121 nm. The CMNPs and the optimized MLs were fully characterized from chemical and physical perspectives. In the presence of dual AMF and NIR laser treatment, a suspension of MLs demonstrated amplified heat generation from dual hyperthermia (MH)-photothermia (PT) in comparison with single MH or PT. In vitro cell culture experiments confirmed the efficient cellular uptake of the MLs from confocal laser scanning microscopy due to passive accumulation in human glioblastoma U87 cells originated from the cationic nature of MLs. The inducible thermal effects mediated by MLs after endocytosis also led to enhanced cytotoxicity and cumulative cell death of cancer cells in the presence of AMF-NIR lasers. This functional nanocomposite will be a potential candidate for bimodal MH-PT dual magneto-photothermal cancer therapy.


Asunto(s)
Glioblastoma/tratamiento farmacológico , Hipertermia Inducida/métodos , Liposomas/química , Nanopartículas de Magnetita/química , Nanocompuestos/química , Fototerapia/métodos , Células 3T3 , Animales , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Ácido Cítrico/química , Endocitosis/efectos de los fármacos , Glioblastoma/radioterapia , Humanos , Hipertermia , Hipertermia Inducida/instrumentación , Rayos Láser , Liposomas/síntesis química , Liposomas/ultraestructura , Campos Magnéticos , Nanopartículas de Magnetita/efectos de la radiación , Nanopartículas de Magnetita/ultraestructura , Ratones , Microscopía Electrónica de Transmisión , Nanocompuestos/efectos de la radiación , Tamaño de la Partícula
2.
Biophys Chem ; 246: 25-34, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30659995

RESUMEN

Tyrosol, hydroxytyrosol and oleuropein are among the major phenolic compounds in fruits, leaves and oils from Olea europaea L. These natural antioxidants molecules revealed several beneficial effects on human health, but a low bioavailability and accessibility to targeted site. Liposomes are drug/nutraceutical delivery carriers, used for driving bioactive molecules to desired target tissues, decreasing potential side effects and protecting the encapsulated molecule from enzymatic metabolic processes. In this study, zwitterionic liposomes containing tyrosol, hydroxytyrosol and oleuropein were synthesized and characterized for their size and surface charge. Particular attention was devoted to the determination of encapsulation efficiency (EE%), quantifying the loaded Tyr, HTyr and Ole amount, by using three different techniques: direct UV spectrophotometry, High Performance Liquid Chromatography and Trolox Equivalent Antioxidant Capacity assay. The results revealed higher EE% for oleuropein. Cyto-toxicity and cyto-compatibility of liposomes were also tested on human chondrocyte cells.


Asunto(s)
Antioxidantes/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Liposomas/síntesis química , Acetatos/administración & dosificación , Catecoles/administración & dosificación , Células Cultivadas , Condrocitos/citología , Condrocitos/efectos de los fármacos , Suplementos Dietéticos , Humanos , Glucósidos Iridoides , Iridoides/administración & dosificación , Liposomas/toxicidad , Olea/química , Alcohol Feniletílico/administración & dosificación , Alcohol Feniletílico/análogos & derivados
3.
Biomacromolecules ; 20(1): 118-129, 2019 01 14.
Artículo en Inglés | MEDLINE | ID: mdl-30347145

RESUMEN

This work aims at designing functional biomaterials through selective chemical modification of xylan from beechwood. Acidic hydrolysis of xylan led to well-defined oligomers with an average of six xylose units per chain and with an aldehyde group at the reductive end. Reductive amination was performed on this aldehyde end group to introduce an azide reactive group. "Click chemistry" was then applied to couple these hydrophilic xylans moieties with different hydrophobic fatty acid methyl esters that were previously functionalized with complementary alkyne functions. The resulting amphiphilic bio-based conjugates were then self-assembled using three different methods, namely, direct solubilization, thin-film rehydration/extrusion, and microfluidics. Well-defined micelles and vesicles were obtained, and their high loading capacity with propiconazole as an antifungal active molecule was shown. The resulting vesicles loaded with propiconazole in a microfluidic process proved to significantly improve the antifungal activity of propiconazole, demonstrating the high potential of such xylan-based amphiphiles.


Asunto(s)
Liposomas/síntesis química , Tensoactivos/síntesis química , Xilanos/química , Antifúngicos/administración & dosificación , Antifúngicos/farmacología , Química Clic/métodos , Ácidos Grasos/química , Micelas , Trametes/efectos de los fármacos , Triazoles/administración & dosificación , Triazoles/farmacología
4.
Colloids Surf B Biointerfaces ; 175: 654-662, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30590326

RESUMEN

0.5-1% of the world's population is affected by vitiligo, a disease characterized by a gradual depigmentation of the skin. Baicalin and berberine are natural compounds with beneficial activities, such as antioxidant, anti-inflammatory and proliferative effects. These polyphenols could be useful for the treatment of vitiligo symptoms, and their efficacy can be improved by loading in suitable carriers. The aim of this work was to formulate and characterize baicalin or berberine loaded ultradeformable vesicles, and demonstrate their potential as adjuvants in the treatment of vitiligo. The vesicles were produced using a previously reported simple, scalable method. Their morphology, size distribution, surface charge and entrapment efficiency were assessed. The ability of the vesicles to promote the permeation of the polyphenols was evaluated. The antioxidant and photoprotective effects were investigated in vitro using keratinocytes and fibroblasts. Further, the stimulation of melanin production and tyrosinase activity in melanocytes after treatment with the vesicles were assessed. Ultradeformable vesicles were small in size, homogeneously dispersed, and negatively charged. They were able to incorporate high amounts of baicalin and berberine, and promote their skin permeation. In fact, the polyphenols concentration in the epidermis was higher than 10%, which could be indicative of the formation of a depot in the epidermis. The vesicles showed remarkable antioxidant and photoprotective capabilities, presumably correlated with the stimulation of melanin production and tyrosinase activity. In conclusion, baicalin or berberine ultradeformable vesicles, and particularly their combination, may represent promising nanosystem-based adjuvants for the treatment of vitiligo symptoms.


Asunto(s)
Antioxidantes/farmacología , Berberina/farmacología , Flavonoides/farmacología , Melaninas/biosíntesis , Melanocitos/efectos de los fármacos , Protectores Solares/farmacología , Animales , Antioxidantes/metabolismo , Berberina/metabolismo , Línea Celular Transformada , Composición de Medicamentos/métodos , Flavonoides/metabolismo , Humanos , Queratinocitos/citología , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Queratinocitos/efectos de la radiación , Liposomas/síntesis química , Melaninas/agonistas , Melanocitos/citología , Melanocitos/metabolismo , Melanocitos/efectos de la radiación , Monofenol Monooxigenasa/metabolismo , Permeabilidad , Piel/efectos de los fármacos , Piel/metabolismo , Absorción Cutánea , Electricidad Estática , Protectores Solares/metabolismo , Porcinos , Rayos Ultravioleta , Vitíligo/tratamiento farmacológico
5.
IET Nanobiotechnol ; 12(6): 727-732, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30104445

RESUMEN

Research dealing with early diagnosis and efficient treatment in colon cancer to improve patient's survival is still under investigation. Chemotherapeutic agent result in high systemic toxicity due to their non-specific actions on DNA repair and/or cell replication. Traditional medicine such as Lycopodium clavatum (LC) has been claimed to have therapeutic potentials against cancer. The present study focuses on targeted drug delivery of cationic liposomal nanoformulated LC (CL-LC) in colon cancer cells (HCT15) and comparing the efficacy with an anti-colon cancer drug, 7-ethyl-10-hydroxy-camptothecin (SN38) along with its nanoformulated form (CL-SN38). The colloidal suspension of LC was made using thin film hydration method. The drugs were characterised using ultraviolet, dynamic light scattering, scanning electron microscopy, energy, dispersive X-ray spectroscopy. Invitro drug release showed kinetics of 49 and 89% of SN38 and LC, whereas CL-SN38 and CL-LC showed 73 and 74% of sustained drug release, respectively. Studies on morphological changes, cell viability, cytotoxicity, apoptosis, cancer-associated gene expression analysis of Bcl-2, Bax, p53 by real-time polymerase chain reaction and western blot analysis of Bad and p53 protein were performed. Nanoformulated LC significantly inhibited growth and increased the apoptosis of colon cancer cells indicating its potential anti-cancer activity against colon cancer cells.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Neoplasias del Colon/tratamiento farmacológico , Liposomas/farmacología , Lycopodium/química , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacocinética , Apoptosis/efectos de los fármacos , Cationes/química , Supervivencia Celular/efectos de los fármacos , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Liposomas/síntesis química , Liposomas/química , Nanocompuestos/química , Células Tumorales Cultivadas
6.
Eur Phys J E Soft Matter ; 40(6): 63, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28620695

RESUMEN

The impact of selected metallophthalocyanines, featuring diverse molecular structure, upon the fluidity of liposome membranes was studied using the spin label EPR technique. The "mono"-type MPc's (M = Zn, Sn; Pc = C32H16N8 is the phthalocyanine ligand) and sandwich LnPc2 complexes (Ln = Nd, Sm, Gd) were explored. Liposomes were obtained in a sonication process, from egg yolk lecithin (EYL) in water. TEMPO and 16-DOXYL spin labels were used to monitor the peripheral and central part of the lipid double layer, respectively, which allowed to localize the phthalocyanine additive within the bilayer, as well as to perform independent measurements of changes in fluidity upon addition thereof. All the complexes tested were found to increase the fluidity in the middle of the lipid bilayer. However, at the water-lipid interface the LnPc2 compounds showed a relative small effect upon the phospholipids' arrangement, whereas in the case of ZnPc and SnPc it was found much more pronounced. EPR results were supplemented by measurements of static electrical charge, the investigated phthalocyanines may potentially feed into the membrane thus affecting its stability.


Asunto(s)
Liposomas/química , Compuestos Organometálicos/química , Óxidos N-Cíclicos/química , Espectroscopía de Resonancia por Spin del Electrón , Lecitinas/química , Liposomas/síntesis química , Sonicación
7.
Curr Drug Deliv ; 14(8): 1053-1059, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27572089

RESUMEN

BACKGROUND: Curcumin is a yellow polyphenolic chemopreventive agent isolated from the rhizomes of Curcuma longa. It is approved as Generally Regarded as Safe by US FDA. Nonetheless, its clinical success is limited due to its poor aqueous solubility, fast metabolism and short biological half-life attributes. OBJECTIVE: Quercetin-decorated liposomes of curcumin (QCunp) are perceived to be able to overcome these biopharmaceutical drawbacks. METHODS: Curcumin liposomes with/without quercetin were prepared by lipid hydration technique. The liposomes were characterized for their particle size, zeta potential, surface morphology, drug loading and release characteristics. The toxicity of the liposomes were evaluated in-vitro and their invivo efficacy were tested against Dalton's ascites lymphoma in mice. RESULTS: Liposomes designed showed particle size of 261.8 ± 2.1 nm with a negative zeta potential of -22.6±1.6 mV. Quercetin decorated liposomes were more effective in increasing the life span and body weight of lymphoma inflicted mice compared to those without quercetin. Similarly, the presence of quercetin also contributed to enhanced cytotoxicity of the liposomal formulation towards HT-29 cells and HCT-15 cells. CONCLUSION: Newer liposomal design exhibited promising potential to emerge as alternative anticancer therapeutics.


Asunto(s)
Antineoplásicos/química , Curcumina/administración & dosificación , Curcumina/química , Liposomas/química , Linfoma/tratamiento farmacológico , Quercetina/química , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Proliferación Celular/efectos de los fármacos , Curcumina/farmacología , Curcumina/uso terapéutico , Ensayos de Selección de Medicamentos Antitumorales , Células HT29 , Humanos , Liposomas/administración & dosificación , Liposomas/síntesis química , Linfoma/patología , Masculino , Ratones , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/patología , Tamaño de la Partícula , Quercetina/administración & dosificación , Propiedades de Superficie , Células Tumorales Cultivadas
8.
Photochem Photobiol Sci ; 14(5): 972-81, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25793654

RESUMEN

Photodynamic therapy (PDT) has been successfully implemented as a treatment for wet age-related macular degeneration (AMD), but very few photosensitizers have been developed for clinical use. Herein, we describe a novel formulation of liposomal hypocrellin B (LHB) that was prepared by high-pressure homogenization. The encapsulation efficiency and PDT efficacy in vitro of this new preparation were found to remain nearly constant over 1 year. Moreover, LHB is rapidly cleared from the blood, with a half-life of 2.319 ± 0.462 h and a very low serum concentration at 24 h after injection. Testing in a rat model of choroidal neovascularization (CNV) showed that leakage of blood vessels in CNV lesions was significantly reduced when LHB PDT was given at a dose of 1 mg kg(-1) along with yellow laser irradiation; the damage to the collateral retina and the retinal pigment epithelium was minimal. Skin phototoxicity assays showed that only two of the 200 mice given a 4 mg per kg dose of LHB experienced an inflammatory reaction in the auricle irradiated at 24 h after dosing. These data collectively indicate that LHB may be a safe and effective photosensitizer for vascular-targeted PDT of AMD.


Asunto(s)
Perileno/análogos & derivados , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/administración & dosificación , Quinonas/administración & dosificación , Degeneración Macular Húmeda/terapia , Animales , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Células Cultivadas , Neovascularización Coroidal , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Oído/patología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/fisiología , Células Endoteliales/efectos de la radiación , Femenino , Liposomas/síntesis química , Pulmón/irrigación sanguínea , Masculino , Ratones , Microvasos/efectos de los fármacos , Microvasos/fisiología , Microvasos/efectos de la radiación , Tamaño de los Órganos , Perileno/administración & dosificación , Perileno/síntesis química , Perileno/farmacocinética , Perileno/toxicidad , Fármacos Fotosensibilizantes/síntesis química , Fármacos Fotosensibilizantes/farmacocinética , Fármacos Fotosensibilizantes/toxicidad , Quinonas/síntesis química , Quinonas/farmacocinética , Quinonas/toxicidad , Ratas , Retina/efectos de los fármacos , Retina/patología , Retina/efectos de la radiación , Piel/efectos de los fármacos , Piel/patología , Piel/efectos de la radiación , Degeneración Macular Húmeda/patología
9.
J Liposome Res ; 24(3): 204-15, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24484536

RESUMEN

Niosomes embodying ethanol and minimum amount of cholesterol (ethoniosomes) could be promising ocular delivery systems for water soluble and insoluble drugs. This manuscript reports on novel nano-sized elastic niosomes (ethoniosomes) composed of Span 60: cholesterol (7:3 mol/mol) and ethanol, for ocular delivery of prednisolone acetate (Pred A) and prednisolone sodium phosphate (Pred P). These ethoniosomes were prepared with the thin film hydration (TFH) and ethanol injection (EI) methods, characterized for percentage entrapment efficiency (% EE), size, zeta potential, morphology, elasticity, in vitro release and physical stability. Ocular irritation, bioavailability and anti-inflammatory effects were evaluated and compared with the conventional suspension and solution eye drops. The prepared ethoniosomal vesicles (EV) had a Z-average diameter of 267 nm, zeta potential of approximately -40 mV and % change in size after extrusion of 4%. They were physically stable for at least 2 months at 4 °C. The prepared EV showed good ocular tolerability using the modified Draize's test and the estimated relative ocular bioavailability for Pred A EV and Pred P EV was 1.54 and 1.75 times greater than that for the suspension and solution eye drops, respectively. The time required for complete healing from the clove oil-induced severe ocular inflammation was reduced to half with Pred A and Pred P EV. More interestingly, the intraocular pressure (IOP) elevation side effect recorded for Pred A and Pred P EV was significantly less than that for the conventional suspension and solution eye drops.


Asunto(s)
Antiinflamatorios/administración & dosificación , Endoftalmitis/tratamiento farmacológico , Liposomas/síntesis química , Prednisolona/análogos & derivados , Animales , Disponibilidad Biológica , Química Farmacéutica , Aceite de Clavo , Composición de Medicamentos , Estabilidad de Medicamentos , Elasticidad , Endoftalmitis/inducido químicamente , Etanol/química , Tamaño de la Partícula , Prednisolona/administración & dosificación , Conejos
10.
Drug Deliv ; 20(3-4): 120-6, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23651102

RESUMEN

Lactic acidosis is a serious, metabolic complication that may occur due to metformin hydrochloride (MH) accumulation during the treatment of diabetes mellitus. The aim of this study is to enhance the bioavailability of MH by oral route. Span 40 and cholesterol were used for the preparation of MH-loaded niosomes by the reverse phase evaporation technique. Dicetyl phosphate (DCP) and 1,2-dioleoyl-3-trimethylammonium-propane chloride salt (DOTAP) were used to obtain negatively and positively charged vesicles, respectively. The mean particle size ranged from 223.5 to 384.6 nm and the MH-loaded niosomes' surface was negatively charged in the absence of charge inducing agents (-16.6 ± 1.4 mV) and also with DCP (-26.9 ± 1.0 mV), while it was positively charged (+8.7 ± 1.2 mV) with DOTAP. High entrapment efficiency was observed in all the formulations. MH-loaded niosomes were found to effectively sustain the release of drug, particularly with positively charged niosomes. The bioavailability of MH-loaded niosomes was assessed by measuring the serum values of glucose and metformin in the different studied Wistar rats groups. The pharmacokinetic data of MH-loaded niosomal preparation showed a significant prolongation and increased intensity of hypoglycemic effect more than that observed for free MH solution. Area above the blood glucose levels-time curve (AAC), maximum hypoglycemic response and time of maximum response (T(max)) were significantly higher (p < 0.001) when MH was administered in niosomal form compared to free drug solution. It could be concluded that MH-loaded niosome is promising extended-release preparation with better hypoglycemic efficiency.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Liposomas/administración & dosificación , Liposomas/síntesis química , Metformina/administración & dosificación , Metformina/síntesis química , Animales , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Química Farmacéutica , Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/síntesis química , Preparaciones de Acción Retardada/metabolismo , Evaluación Preclínica de Medicamentos/métodos , Liposomas/metabolismo , Masculino , Metformina/metabolismo , Distribución Aleatoria , Ratas , Ratas Wistar
11.
Colloids Surf B Biointerfaces ; 104: 254-61, 2013 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-23333913

RESUMEN

The development of new polymer-liposome complexes (PLCs) as delivery systems is the key issue of this work. Three main areas are dealt with: polymer synthesis/characterization, liposome formulation/characterization and evaluation of the PLCs uptake by eukaryotic cells. Poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) with low molecular weight and narrow polydispersity was synthesized by Atom Transfer Radical Polymerization (ATRP). The polymers were synthesized using two different bromide initiators (cholesteryl-2-bromoisobutyrate and ethyl 2-bromoisobutyrate) as a route to afford PDMAEMA and CHO-PDMAEMA. Both synthesized polymers (PDMAEMA and CHO-PDMAEMA) were incorporated in the preparation of lecithin liposomes (LEC) to obtain PLCs. Three polymer/lipid ratios were investigated: 5, 10 and 20%. Physicochemical characterization of PLCs was carried out by determining the zeta potential, particle size distribution, and the release of fluorescent dyes (carboxyfluorescein CF and calcein) at different temperatures and pHs. The leakage experiments showed that CHO covalently bound to PDMAEMA strongly stabilizes PLCs. The incorporation of 5% CHO-PDMAEMA to LEC (LEC_CHO-PD5) appeared to be the stablest preparation at pH 7.0 and at 37°C. LEC_CHO-PD5 destabilized upon slight changes in pH and temperature, supporting the potential use of CHO-PDMAEMA incorporated to lecithin liposomes (LEC_CHO-PDs) as stimuli-responsive systems. In vitro studies on Raw 264.7 and Caco-2/TC7 cells demonstrated an efficient incorporation of PLCs into the cells. No toxicity of the prepared PLCs was observed according to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. These results substantiate the efficiency of CHO-PDMAEMA incorporated onto LEC to assist for the release of the liposome content in mildly acidic environments, like those found in early endosomes where pH is slightly lower than the physiologic. In summary, the main achievements of this work are: (a) novel synthesis of CHO-PDMAEMA by ATRP, (b) stabilization of LEC by incorporation of CHO-PDMAEMA at neutral pH and destabilization upon slight changes of pH, (c) efficient uptake of LEC_CHO-PDs by phagocytic and non-phagocytic eukaryotic cells.


Asunto(s)
Colesterol/farmacocinética , Liposomas/farmacocinética , Metacrilatos/farmacocinética , Nylons/farmacocinética , Animales , Células CACO-2 , Línea Celular , Colesterol/química , Sistemas de Liberación de Medicamentos , Colorantes Fluorescentes/química , Humanos , Concentración de Iones de Hidrógeno , Lecitinas/química , Liposomas/síntesis química , Liposomas/química , Metacrilatos/química , Ratones , Estructura Molecular , Nylons/química , Tamaño de la Partícula , Polimerizacion , Propiedades de Superficie , Temperatura , Distribución Tisular
12.
J Liposome Res ; 22(3): 215-23, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22397357

RESUMEN

Seabuckthorn (SBT; Hipphophae rhamnoides) leaf extract obtained by supercritical carbon dioxide (SCCO(2)) using ethanol as an entrainer, containing mainly flavanoids as bioactive principles with antioxidant and antibacterial properties, was used for the preparation of liposomes. Liposomes are promising drug carriers with sustained release because they can enhance the membrane penetration of drugs, deliver the entrapped drugs across cell membranes, and improve extract stability and bioavailability. The aim of the present study was to compare the two different methods of liposome production: the Bangham thin-film method and SCCO(2) gas antisolvent method (SCCO(2) GAS) for the incorporation of SBT leaf extract in terms of particle size, morphology, encapsulation efficiency, antioxidant activity, and thermal stability. Liposomes obtained with the thin-film method were multilamellar vesicles with average particle size (3,740 nm), encapsulation efficiency (14.60%), and particle-size range (1.57-6.0 µm), respectively. On the other hand, liposomes by the SCCO(2) GAS method were nanosized (930 nm) with an improved encapsulation efficiency (28.42%) and narrow range of size distribution (0.48-1.07 µm), respectively. Further, the antioxidant activity of leaf extract of SBT was determined by the 2 diphenyl-1-picrylhydrazyl method and expressed as Trolox equivalents as well as of the intercalated extract in liposomes. The oxidative stability of SBT encapsulated in liposomes was again estimated using differential scanning calorimetry (DSC). Thermal-oxidative decomposition of the samples (i.e., pure liposomes and encapsulated extracts) and the modification of the main transition temperature for the lipid mixture and the splitting of the calorimetric peak in the presence of the antioxidants were also studied by DSC. After encapsulation in liposomes, antioxidant activity proved to be higher than those of the same extracts in pure form.


Asunto(s)
Dióxido de Carbono/química , Hippophae/química , Liposomas/síntesis química , Nanotecnología/métodos , Extractos Vegetales/química , Hojas de la Planta/química , Antioxidantes/química , Compuestos de Bifenilo/química , Rastreo Diferencial de Calorimetría , Cromanos/química , Composición de Medicamentos/métodos , Estabilidad de Medicamentos , Etanol/química , Lípidos/química , Liposomas/química , Nanopartículas/química , Oxidación-Reducción , Tamaño de la Partícula , Picratos/química , Sensibilidad y Especificidad , Sonicación/métodos , Temperatura de Transición
13.
Nanotechnology ; 23(10): 105606, 2012 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-22362251

RESUMEN

Composite microparticles, consisting of polyvinylpyrrolidone (PVP), naproxen (NAP) and lecithin (PC), have been successfully prepared using an electrospraying process and exploited as templates to manipulate molecular self-assembly for the synthesis of liposomes in situ. Field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) observations demonstrate that the microparticles have an average diameter of 960 ± 140 nm and a homogeneous structure. X-ray diffraction (XRD) patterns, differential scanning calorimetry (DSC) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) results verify that the building blocks NAP and PC are scattered in the polymer matrix in a molecular way owing to the very fast drying of the electrospraying process and the favorable secondary interactions among the components. FESEM, scanning probe microscope (SPM) and TEM observations demonstrate that the liposomes can be achieved through molecular self-assembly in situ when the microparticles contact water thanks to 'like prefers like' and by means of the confinement effect of the microparticles. The liposomes have an encapsulation rate of 91.3%, and 80.7% of the drug in the liposomes can be freed into the dissolution medium in a sustained way and by a diffusion mechanism over a period of 24 h. The developed strategy not only provides a new, facile, and effective method to assemble and organize molecules of multiple components into liposomes with electrosprayed microparticles as templates, but also opens a new avenue for nanofabrication in a step-by-step and controllable way.


Asunto(s)
Técnicas Electroquímicas/métodos , Liposomas/química , Liposomas/síntesis química , Nanocompuestos/química , Nanotecnología/métodos , Calor , Lecitinas/química , Naproxeno/química , Naproxeno/farmacocinética , Tamaño de la Partícula , Povidona/química
14.
Molecules ; 16(9): 7880-92, 2011 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-22143548

RESUMEN

The main purpose of this study was to evaluate the intestinal absorption and the antineoplastic effect of the poorly water-soluble drug celastrol when liposomes were used as oral drug delivery system. Liposomes were prepared by the ethanol-injection method. An optimized liposome formulation composed of phospholipid, cholesterol and Tween-80 resulted in favorable encapsulation efficiency at 98.06 ± 0.94%. Homogeneous and stable particle size of 89.6 ± 7.3 nm and zeta potential of -(87.7 ± 5.8) mV were determined by laser particle size analyzer. Subsequently, the four-site perfusion rat intestinal model revealed that celastrol-loaded liposomes had improved effective permeability compared to the free drug in four intestinal segments (p < 0.05). Moreover, celastrol-loaded liposomes could also inhibit the tumor growth in C57BL/6 mice. These results suggest that liposomes could be a promising perioral carrier for celastrol.


Asunto(s)
Carcinoma Pulmonar de Lewis/tratamiento farmacológico , Sistemas de Liberación de Medicamentos/métodos , Liposomas/administración & dosificación , Triterpenos/administración & dosificación , Triterpenos/farmacología , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacología , Carcinoma Pulmonar de Lewis/patología , Química Farmacéutica , Absorción Intestinal/efectos de los fármacos , Intestinos/efectos de los fármacos , Liposomas/síntesis química , Liposomas/química , Masculino , Medicina Tradicional China , Ratones , Ratones Endogámicos C57BL , Triterpenos Pentacíclicos , Perfusión/métodos , Ratas , Ratas Sprague-Dawley , Triterpenos/química
15.
Yakugaku Zasshi ; 131(10): 1519-25, 2011.
Artículo en Japonés | MEDLINE | ID: mdl-21963980

RESUMEN

In this study, 162 students in the 6 year Pharmacy Program at the School of Pharmacy, Iwate Medical University were asked to prepare liposomal preparations using chicken egg yolk and to evaluate their properties with the aim of developing novel liposomes. High-purity lecithins are generally used for preparing liposomes but they are expensive. On the other hand, egg yolk has various components, including lecithin and cholesterol, which are important components for the formation of liposomes, so it was hypothesized that liposomes prepared from egg yolk may participate in the formation of cell membrane in chicks. Both liposomes from egg yolk (YL) and from lecithin (LL) exhibited Malthesian crosses using a polarizing microscope and multilamellar vesicles were observed, confirming that liposomal preparations from egg yolk were useful. The particle size of YL was about 100 nm with one peak. Furthermore, the YL are believed to be viable under different conditions because the particle size did not change when they were prepared in buffers having different pH values. The results of these experiments indicate that liposomal preparations from egg yolk can serve as natural materials, although some obstacles remain. This is a unique approach for carrying out practical training in our 6 year pharmaceutical science program.


Asunto(s)
Educación en Farmacia/métodos , Yema de Huevo , Liposomas/síntesis química , Animales , Tampones (Química) , Embrión de Pollo , Concentración de Iones de Hidrógeno , Japón , Lecitinas , Liposomas/ultraestructura , Microscopía de Polarización , Tamaño de la Partícula , Facultades de Farmacia , Estudiantes de Farmacia
16.
J Colloid Interface Sci ; 364(1): 31-8, 2011 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-21885053

RESUMEN

Polymer-hybridized liposomes (PHLs) of saturated lecithin were formed by association of poly(asparagines) grafted with alkyl chains (PAsn-g-Cn). The thermal, physical, and surface properties of the polymer-hybridized liposomes were examined with varying polymer concentration, alkyl chain length (C(8), C(12), C(18), C(22)), and degree of substitution (DS) in the polymer. The inclusion of the polymer raised the membrane fluidity of liposomes. By the incorporation of small amount of polymer, the membrane rigidity of liposomes dropped sharply and then increased close to the original level as the polymer concentrations increased in the cases of PAsn-g-C(18) and PAsn-g-C(22). Also, the membrane rigidity and stability of PHLs increased with alkyl chain length at the same polymer concentration. The surface charge of PHL associated with PAsn-g-C(22) was changed by DS of alkyl chains. The polymer bearing long alkyl chains (C(12), C(18), C(22)) formed PHLs well at low polymer concentration and the number of disk-shaped polymer-lipid mixed micelles increased with polymer concentration. The anchored polymers induced shifts in gel-to-liquid crystal transition temperature (Tc) of the vesicles and Tc varied with polymer concentration, alkyl chain length, and DS of the polymer.


Asunto(s)
Ácido Aspártico/análogos & derivados , Liposomas/química , Péptidos/química , Ácido Aspártico/química , Lecitinas/química , Liposomas/síntesis química , Tamaño de la Partícula , Propiedades de Superficie
17.
Pharm Res ; 28(11): 2896-909, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21732153

RESUMEN

PURPOSE: To investigate of an approach to stabilize a novel pyridinol based α-tocopherol analogue (1) as a prodrug by acetylation of its phenol moiety. METHODS: Biochemical indicators of oxidative stress in mitochondria were utilized to gain insight into the cytoprotective mechanism(s) of compound 1 acetate. Oxygen free radical scavenging activity was measured using DCF probe in a cultured cell model system that had been placed under oxidative stress. Lipid peroxidation was examined both in a cell-free system and in oxidatively stressed cultured cells. The bioenergetic parameters of mitochondria were evaluated by measuring mitochondrial membrane potential (Δψ(m)) and the MPT. RESULTS: The present results suggest strongly that the antioxidant efficacy of compound 1 can be improved by using it as a prodrug. The tested prodrug has shown to be activated as a function of time, presumably due to susceptibility to enzymatic hydrolysis, and exhibits an antioxidant effect in time-dependent manner, providing a compound that is more effective than α-tocopherol acetate with regard to all protective properties studied. CONCLUSIONS: An effective approach to stabilize compound 1 was realized by using its acetate as a prodrug.


Asunto(s)
Antioxidantes/química , Sistemas de Liberación de Medicamentos , Liposomas/síntesis química , Profármacos/síntesis química , Vitamina E/análogos & derivados , Vitamina E/química , Acetatos/análisis , Acetatos/síntesis química , Acetatos/química , Acetatos/metabolismo , Antioxidantes/metabolismo , Antioxidantes/farmacología , Compuestos de Boro/metabolismo , Técnicas de Cultivo de Célula , Línea Celular Tumoral , Supervivencia Celular , Sistema Libre de Células , Composición de Medicamentos , Evaluación Preclínica de Medicamentos , Humanos , Peroxidación de Lípido , Liposomas/química , Potencial de la Membrana Mitocondrial , Mitocondrias/metabolismo , Oxidación-Reducción , Estrés Oxidativo , Profármacos/química , Profármacos/metabolismo , Profármacos/farmacología , Especies Reactivas de Oxígeno/análisis , Especies Reactivas de Oxígeno/metabolismo , Vitamina E/metabolismo , Vitamina E/farmacología
18.
Nanotechnology ; 22(31): 315102, 2011 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-21730756

RESUMEN

In this paper, we describe the synthesis and characterization of a nanosized, thermosensitive magnetoliposome encapsulating magnetic nanoparticles (MZFs) and antitumor drugs (As(2)O(3)). The nanoliposomes were spherical and mostly single volume, with an average diameter of 128.2 nm. Differential scanning calorimetry (DSC) showed a liposome phase transition temperature of 42.71 °C. After that, we studied the liposomes' anti-hepatoma effect in vitro and in vivo. The antitumor effect of the nanoliposomes on human hepatoma cells, SMMC-7721, and changes in expression of apoptosis-related proteins were examined in vitro. The results show that As(2)O(3)/MZF thermosensitive magnetoliposomes combined with hyperthermia had a great impact on the Bax/Bcl-2 ratio, which increased to 1.914 and exhibited a rapid response to induce apoptosis of tumor cells. An in situ rabbit liver tumor model was established and used to evaluate the antitumor effect of combined hyperthermia and chemotherapy following transcatheter arterial embolization with As(2)O(3)/MZF thermosensitive magnetoliposomes. The results demonstrated a strong anti-hepatoma effect, with a tumor volume inhibition rate of up to 85.22%. Thus, As(2)O(3)/MZF thermosensitive magnetoliposomes may play a great role in the treatment of hepatocarcinoma.


Asunto(s)
Antineoplásicos/uso terapéutico , Arsenicales/uso terapéutico , Hipertermia Inducida , Liposomas/química , Neoplasias Hepáticas Experimentales/terapia , Nanopartículas/química , Óxidos/uso terapéutico , Animales , Antineoplásicos/administración & dosificación , Trióxido de Arsénico , Arsenicales/administración & dosificación , Rastreo Diferencial de Calorimetría , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Terapia Combinada , Humanos , Liposomas/síntesis química , Liposomas/ultraestructura , Hígado/efectos de los fármacos , Hígado/patología , Neoplasias Hepáticas Experimentales/tratamiento farmacológico , Neoplasias Hepáticas Experimentales/patología , Magnetismo , Nanopartículas/ultraestructura , Óxidos/administración & dosificación , Conejos
19.
Biomed Pharmacother ; 64(9): 615-23, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20888179

RESUMEN

We prepared the core-shell structure adriamycin lipiodol microemulsions (ADM-CSLMs) and evaluated their in vivo antitumor effects in combination with Diethyldithiocarbamate (DDC). Two types of ADM-CSLMs, adriamycin liposome-lipiodol microemulsion(ADM-LLM) and adriamycin microsphere lipiodol microemulsion (ADM-MLM), were prepared through the emulsification method. The drug loading and encapsulation efficiency of ADM-CSLMs were measured by the high-performance liquid chromatograph (HPLC). The size and shape of the ADM-CSLMs were determined by an atom force microscopy (AFM), a transmission electron microscopy (TEM), and a particle size analyzer, respectively. The synergistic effects of DDC and ADM-CSLMs for cancer treatment of carcinoma drug-resistance cell was evaluated by the MTT method, the activation of superoxide dismutase (SOD) was detected by chemiluminescence, and the ADM accumulation in cells was measured by flow cytometry. Walker-256 carcinoma was transplanted to the livers of the male SD rats, ADM-CSLMs were administrated to the livers of the rats by intervention hepatic artery embolization through microsurgery. The tumor growth and animal survival were evaluated. The results show that the average diameter of ADM-LLM and ADM-MLM were 4.23 ± 1.2 µm and 4.67 ± 1.4 µm, respectively, and their ADM encapsulation efficiency were 83.7% and 87.2% with respect to loading efficiency of 82 µg/ml and 91 µg/ml. The tumor growth and animal survival in two of the ADM-CSLMs combined with DDC groups were significantly higher than that of ADM only treatment, ADM liposome combined with DDC (P < 0.01), as well as the ADM microsphere combined with DDC (P < 0.01). Therefore, ADM-CSLMs are useful carriers for the treatment of carcinoma and their anti-tumor effect can be enhanced by DDC in a suitable concentration.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Ditiocarba/farmacología , Doxorrubicina/farmacología , Emulsiones/síntesis química , Aceite Etiodizado/química , Animales , Línea Celular Tumoral , Ditiocarba/administración & dosificación , Doxorrubicina/administración & dosificación , Doxorrubicina/química , Doxorrubicina/farmacocinética , Sinergismo Farmacológico , Humanos , Liposomas/síntesis química , Liposomas/ultraestructura , Masculino , Tamaño de la Partícula , Ratas , Ratas Sprague-Dawley , Ensayos Antitumor por Modelo de Xenoinjerto/métodos
20.
Int J Oncol ; 37(1): 211-8, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20514413

RESUMEN

In the management of metastatic breast cancer, fewer recognized therapeutic standards are available as compared to the early stages of the disease. Thus, it is pertinent to search for new, effective therapy to improve survival, tolerability and quality of life of patients. In this study, a liposomal formulation was developed for a novel dihydrofolate reductase (DHFR) inhibitor, M-V-05. Drug encapsulation into liposomes was achieved by the citrate-based, pH gradient loading technique, with a final drug-to-lipid weight ratio of 0.1:1. The liposome formulation exhibited a sustained release profile of the encapsulated drug that followed first order release kinetics. Liposomal M-V-05 was found to be more effective than the standard DHFR inhibitor, methotrexate, and its activity was comparable to liposomal doxorubicin, with IC50 values of 37 and 59 microM achieved in MDA-MB-231 and JIMT-1 cells, respectively. Similar cytotoxicity was observed in primary patient samples of invasive ductal carcinoma of the breast. The combination of liposomal M-V-05 and liposomal doxorubicin in fixed molar ratio of 3:1 was additive in cytotoxicity, allowing the concentrations of liposomal doxorubicin and liposomal M-V-05 to be reduced by 62 and 46%, respectively. Taken together, liposomal M-V-05 represents a promising agent and offers a potential new adjuvant therapy for breast cancer treatment.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Carcinoma/tratamiento farmacológico , Antagonistas del Ácido Fólico/administración & dosificación , Liposomas/síntesis química , Liposomas/uso terapéutico , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacocinética , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Carcinoma/metabolismo , Carcinoma/patología , Supervivencia Celular/efectos de los fármacos , Química Farmacéutica , Relación Dosis-Respuesta a Droga , Composición de Medicamentos/métodos , Evaluación Preclínica de Medicamentos , Femenino , Antagonistas del Ácido Fólico/farmacocinética , Humanos , Concentración de Iones de Hidrógeno , Liposomas/metabolismo , Modelos Biológicos , Compuestos de Espiro/administración & dosificación , Compuestos de Espiro/síntesis química , Compuestos de Espiro/uso terapéutico , Tetrahidrofolato Deshidrogenasa/metabolismo , Factores de Tiempo , Triazinas/administración & dosificación , Triazinas/síntesis química , Triazinas/uso terapéutico , Células Tumorales Cultivadas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA