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1.
J Am Chem Soc ; 142(7): 3540-3547, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31986022

RESUMO

Covalent organic frameworks (COFs) are commonly synthesized under harsh conditions yielding unprocessable powders. Control in their crystallization process and growth has been limited to studies conducted in hazardous organic solvents. Herein, we report a one-pot synthetic method that yields stable aqueous colloidal solutions of sub-20 nm crystalline imine-based COF particles at room temperature and ambient pressure. Additionally, through the combination of experimental and computational studies, we investigated the mechanisms and forces underlying the formation of such imine-based COF colloids in water. Further, we show that our method can be used to process the colloidal solution into 2D and 3D COF shapes as well as to generate a COF ink that can be directly printed onto surfaces. These findings should open new vistas in COF chemistry, enabling new application areas.

2.
Artif Cells Nanomed Biotechnol ; 48(1): 77-83, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31852325

RESUMO

Type 1 diabetes (T1D) is an autoimmune disease caused by the destruction of insulin-producing cells. Due to the ability of apoptotic cells clearance to induce tolerance, we previously generated liposomes rich in phophatidylserine (PS) -a feature of apoptotic cells- loaded with insulin peptides to mimic apoptotic beta-cells. PS-liposomes arrested autoimmunity in experimental T1D through the induction of tolerance. The aim of this study was to investigate the potential of several peptides from different T1D autoantigens encapsulated in (PS)-liposomes for T1D prevention and to assess its safety. T1D autoantigens (Insulin, C-peptide, GAD65 and IA2) were encapsulated in PS-liposomes. Liposomes were administered to the 'gold-standard' model for the study of autoimmune T1D, the Non-Obese Diabetic mouse, that spontaneously develop the disease. Safety and toxicity of liposomes were also determined. Only PS-liposomes encapsulating insulin peptides decrease T1D incidence in the Non-Obese Diabetic mouse model. Disease prevention correlates with a decrease in the severity of the autoimmune islet destruction driven by leukocytes. PS-liposomes neither showed toxic effect nor secondary complications. Among the here referred autoantigens, insulin peptides are the best candidates to be encapsulated in liposomes, like an artificial apoptotic cell, for the arrest of autoimmunity in T1D in a safe manner.

3.
ACS Omega ; 4(22): 19710-19715, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31788602

RESUMO

A high-performance liquid chromatography (HPLC) method was developed to simultaneously quantify three widely used active substances such as coenzyme Q10, phosphatidylserine, and vitamin C. This new method optimizes current timing and costs in the analyses of these three active substances. Additionally, since the analyzed compounds were encapsulated on a cutting-edge liposomal formulation, further processing was necessary to be developed prior to HPLC analyses. The technique was studied and adequately validated in accordance with the guidelines of the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) regarding selectivity, linearity, accuracy, precision, and robustness. After data treatment of results, linear regressions for all active substances showed an optimal linearity with a correlation coefficient of >0.999 in the concentration range between 70 to 130% of the liposomal formulation and less than a 3% relative standard deviation (RSD) in accuracy and precision.

4.
Front Immunol ; 10: 2811, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31849983

RESUMO

Type 1 diabetes (T1D) is prompted by defective immunological tolerance, an event in which dendritic cells (DCs) are crucial as immune response orchestrators. In fact, they contribute to maintaining tolerance to self-antigens, but they can also prompt an immunogenic response against them, leading to autoimmunity. Countless factors can potentially impact on the proper functionality of the DCs, which range from altered subset distribution, impaired phagocytic function to abnormal gene expression. Moreover, in T1D, metabolic dysregulation could impair DC functions as well. Indeed, since T1D clinical course is likely to be more aggressive in children and adolescents and entails severe dysglycemia, the aim of this study was to analyze circulating DCs subpopulations in pediatric T1D at different stages, as well as to characterize their phagocytosis ability and tolerance induction potential. Thus, pediatric patients newly diagnosed with T1D, with established disease and control subjects were recruited. Firstly, DCs subsets from peripheral blood were found quantitatively altered during the first year of disease, but recovered in the second year of progression. Secondly, to study the tolerogenic functionality of DCs, liposomes with phosphatidylserine (PS) were designed to mimic apoptotic beta cells, which are able to induce tolerance, as previously demonstrated by our group in DCs from adult patients with T1D. In this study, monocyte-derived DCs from pediatric patients with T1D and control subjects were assessed in terms of PS-liposomes capture kinetics, and transcriptional and phenotypic changes. DCs from pediatric patients with T1D were found to phagocyte PS-liposomes more slowly and less efficiently than DCs from control subjects, inversely correlating with disease evolution. Nonetheless, the transcription of PS receptors and immunoregulatory genes, cytokine profile, and membrane expression of immunological markers in DCs was consistent with tolerogenic potential after PS-liposomes phagocytosis. In conclusion, T1D progression in childhood entails altered peripheral blood DCs subsets, as well as impaired DCs phagocytosis, although tolerance induction could still function optimally. Therefore, this study provides useful data for patient follow-up and stratification in immunotherapy clinical trials.

5.
Alzheimers Res Ther ; 11(1): 42, 2019 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-31077261

RESUMO

BACKGROUND: ApoJ/clusterin is a multifunctional protein highly expressed in the brain. The implication of ApoJ in ß-amyloid (Aß) fibrillization and clearance in the context of Alzheimer's disease has been widely studied, although the source and concentration of ApoJ that promotes or inhibits Aß cerebral accumulation is not clear yet. ApoJ is abundant in plasma and approximately 20% can appear bound to HDL-particles. In this regard, the impact of plasmatic ApoJ and its lipidation status on cerebral ß-amyloidosis is still not known. Hence, our main objective was to study the effect of a peripheral increase of free ApoJ or reconstituted HDL particles containing ApoJ in an experimental model of cerebral ß-amyloidosis. METHODS: Fourteen-month-old APP23 transgenic mice were subjected to subchronic intravenous treatment with rHDL-rApoJ nanodiscs or free rApoJ for 1 month. Aß concentration and distribution in the brain, as well as Aß levels in plasma and CSF, were determined after treatments. Other features associated to AD pathology, such as neuronal loss and neuroinflammation, were also evaluated. RESULTS: Both ApoJ-based treatments prevented the Aß accumulation in cerebral arteries and induced a decrease in total brain insoluble Aß42 levels. The peripheral treatment with rApoJ also induced an increase in the Aß40 levels in CSF, whereas the concentration remained unaltered in plasma. At all the endpoints studied, the lipidation of rApoJ did not enhance the protective properties of free rApoJ. The effects obtained after subchronic treatment with free rApoJ were accompanied by a reduction in hippocampal neuronal loss and an enhancement of the expression of a phagocytic marker in microglial cells surrounding Aß deposits. Finally, despite the activation of this phagocytic phenotype, treatments did not induce a global neuroinflammatory status. In fact, free rApoJ treatment was able to reduce the levels of interleukin-17 (IL17) and keratinocyte chemoattractant (KC) chemokine in the brain. CONCLUSIONS: Our results demonstrate that an increase in circulating human rApoJ induces a reduction of insoluble Aß and CAA load in the brain of APP23 mice. Thus, our study suggests that peripheral interventions, based on treatments with multifunctional physiological chaperones, offer therapeutic opportunities to regulate the cerebral Aß load.

6.
Front Microbiol ; 10: 689, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31019499

RESUMO

This study sheds light on the biodistribution of orally administered, liposome-encapsulated bacteriophages, and their transcytosis through intestinal cell layers. Fluorochrome-labeled bacteriophages were used together with a non-invasive imaging methodology in the in vivo visualization of bacteriophages in the stomach and intestinal tract of mice. In those studies, phage encapsulation resulted in a significant increase of the labeled phages in the mouse stomach, even 6 h after their oral administration, and without a decrease in their concentration. By contrast, the visualization of encapsulated and non-encapsulated phages in the intestine were similar. Our in vivo observations were corroborated by culture methods and ex vivo experiments, which also showed that the percentage of encapsulated phages in the stomach remained constant (50%) compared to the amount of initially administered product. However, the use of conventional microbiological methods, which employ bile salts to break down liposomes, prevented the detection of encapsulated phages in the intestine. The ex vivo data showed a higher concentration of non-encapsulated than encapsulated phages in liver, kidney, and even muscle up to 6 h post-administration. Encapsulated bacteriophages were able to reach the liver, spleen, and muscle, with values of 38% ± 6.3%, 68% ± 8.6%, and 47% ± 7.4%, respectively, which persisted over the course of the experiment. Confocal laser scanning microscopy of an in vitro co-culture of human Caco-2/HT29/Raji-B cells revealed that Vybrant-Dil-stained liposomes containing labeled bacteriophages were preferably embedded in cell membranes. No transcytosis of encapsulated phages was detected in this in vitro model, whereas SYBR-gold-labeled non-encapsulated bacteriophages were able to cross the membrane. Our work demonstrates the prolonged persistence of liposome-encapsulated phages in the stomach and their adherence to the intestinal membrane. These observations could explain the greater long-term efficacy of phage therapy using liposome-encapsulated phages.

7.
Dig Endosc ; 31(3): 276-282, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30430648

RESUMO

BACKGROUND AND AIM: The study of electrical and rheological properties of solutions to carry out endoscopic resection procedures could determinate the best candidate. An ex vivo study with porcine stomachs was conducted to analyze electrical resistivity (R) and rheological properties (temperature, viscosity, height and lasting of the cushion) of different substances used in these techniques. METHODS: Tested solutions were: 0.9% saline (S), platelet-rich plasma (PRP), Gliceol (GC), hyaluronic acid 2% (HA), Pluronic-F127 20% (PL), saline with 10% glucose (GS), Gelaspan (GP), Covergel-BiBio (TB) and PRP with TB (PRP+TB). Measurements of electrical and rheological properties were done at 0, 15, 30, 45 and 60 min after submucosal injection. RESULTS: Solutions showed a wide variability of transepithelial R after submucosal injection. Substances able to maintain the highest R 60 min postinjection were TB (7 × 104 Ω), HA (7 × 104 Ω) and PL (7 × 104 Ω). Protective solutions against deep thermal injury (Tª lower than 60°C) were PL (47.6°C), TB (55°C) and HA (56.63°C). Shortest time to carry out resections were observed with GC (17.66″), PRP (20.3″) and GS (23.45″). Solutions with less cushion decrease (<25%) after 60 min were TB (11.74%), PL (18.63%) and PRP (22.12%). CONCLUSIONS: Covergel-BiBio, PL and HA were the best solutions with long-term protective effects (transepithelial R, lower thermal injury and less cushion decrease). Solutions with quicker resection time were GC, PRP and GS.


Assuntos
Ressecção Endoscópica de Mucosa , Mucosa Gástrica/cirurgia , Soluções/química , Animais , Impedância Elétrica , Esponja de Gelatina Absorvível/química , Ácido Hialurônico/química , Técnicas In Vitro , Modelos Animais , Plasma Rico em Plaquetas/química , Poloxâmero/química , Reologia , Cloreto de Sódio/química , Suínos
8.
Front Immunol ; 9: 253, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29491866

RESUMO

Type 1 diabetes (T1D) is a metabolic disease caused by the autoimmune destruction of insulin-producing ß-cells. With its incidence increasing worldwide, to find a safe approach to permanently cease autoimmunity and allow ß-cell recovery has become vital. Relying on the inherent ability of apoptotic cells to induce immunological tolerance, we demonstrated that liposomes mimicking apoptotic ß-cells arrested autoimmunity to ß-cells and prevented experimental T1D through tolerogenic dendritic cell (DC) generation. These liposomes contained phosphatidylserine (PS)-the main signal of the apoptotic cell membrane-and ß-cell autoantigens. To move toward a clinical application, PS-liposomes with optimum size and composition for phagocytosis were loaded with human insulin peptides and tested on DCs from patients with T1D and control age-related subjects. PS accelerated phagocytosis of liposomes with a dynamic typical of apoptotic cell clearance, preserving DCs viability. After PS-liposomes phagocytosis, the expression pattern of molecules involved in efferocytosis, antigen presentation, immunoregulation, and activation in DCs concurred with a tolerogenic functionality, both in patients and control subjects. Furthermore, DCs exposed to PS-liposomes displayed decreased ability to stimulate autologous T cell proliferation. Moreover, transcriptional changes in DCs from patients with T1D after PS-liposomes phagocytosis pointed to an immunoregulatory prolife. Bioinformatics analysis showed 233 differentially expressed genes. Genes involved in antigen presentation were downregulated, whereas genes pertaining to tolerogenic/anti-inflammatory pathways were mostly upregulated. In conclusion, PS-liposomes phagocytosis mimics efferocytosis and leads to phenotypic and functional changes in human DCs, which are accountable for tolerance induction. The herein reported results reinforce the potential of this novel immunotherapy to re-establish immunological tolerance, opening the door to new therapeutic approaches in the field of autoimmunity.


Assuntos
Apoptose/imunologia , Células Dendríticas/imunologia , Diabetes Mellitus Tipo 1/imunologia , Tolerância Imunológica/imunologia , Fosfatidilserinas/imunologia , Adolescente , Adulto , Autoantígenos/imunologia , Células Cultivadas , Feminino , Humanos , Imunoterapia/métodos , Lipossomos , Masculino , Pessoa de Meia-Idade , Mimetismo Molecular/imunologia , Fagocitose , Adulto Jovem
9.
Methods Mol Biol ; 1693: 271-283, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29119446

RESUMO

Encapsulation methodologies allow the protection of bacteriophages for overcoming critical environmental conditions. Moreover, they improve the stability and the controlled delivery of bacteriophages which is of great innovative value in bacteriophage therapy. Here, two different encapsulation methodologies of bacteriophages are described using two biocompatible materials: a lipid cationic mixture and a combination of alginate with the antacid CaCO3. To perform bacteriophage encapsulation, a purified lysate highly concentrated (around 1010-1011 pfu/mL) is necessary, and to dispose of a specific equipment. Both methodologies have been successfully applied for encapsulating Salmonella bacteriophages with different morphologies. Also, the material employed does not modify the antibacterial action of bacteriophages. Moreover, both technologies can also be adapted to any bacteriophage and possibly to any delivery route for bacteriophage therapy.


Assuntos
Antibacterianos/uso terapêutico , Bactérias/efeitos dos fármacos , Bacteriófagos , Composição de Medicamentos , Terapia por Fagos , Bactérias/virologia , Humanos
10.
Sci Rep ; 7(1): 14637, 2017 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-29116115

RESUMO

Cerebral ß-amyloidosis is a major feature of Alzheimer's disease (AD), characterized by the accumulation of ß-amyloid protein (Aß) in the brain. Several studies have implicated lipid/lipoprotein metabolism in the regulation of ß-amyloidosis. In this regard, HDL (High Density Lipoprotein)-based therapies could ameliorate pathological features associated with AD. As apolipoprotein J (ApoJ) is a natural chaperone that interacts with Aß, avoiding its aggregation and toxicity, in this study we propose to prepare reconstituted rHDL-rApoJ nanoparticles by assembling phospholipids with recombinant human ApoJ (rApoJ). Hence, rHDL particles were prepared using the cholate dialysis method and characterized by N-PAGE, dynamic light scattering, circular dichroism and electron transmission microscopy. The preparation of rHDL particles showed two-sized populations with discoidal shape. Functionally, rHDL-rApoJ maintained the ability to prevent the Aß fibrillization and mediated a higher cholesterol efflux from cultured macrophages. Fluorescently-labelled rHDL-rApoJ nanoparticles were intravenously administrated in mice and their distribution over time was determined using an IVIS Xenogen® imager. It was confirmed that rHDL-rApoJ accumulated in the cranial region, especially in old transgenic mice presenting a high cerebral Aß load. In conclusion, we have standardized a reproducible protocol to produce rHDL-rApoJ nanoparticles, which may be potentially considered as a therapeutic option for ß-amyloid-related pathologies.


Assuntos
Doença de Alzheimer/terapia , Amiloidose/terapia , Encéfalo/metabolismo , Clusterina/administração & dosagem , Lipoproteínas HDL/administração & dosagem , Nanocompostos/administração & dosagem , Placa Amiloide/prevenção & controle , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Amiloidose/metabolismo , Amiloidose/patologia , Animais , Encéfalo/patologia , Clusterina/química , Modelos Animais de Doenças , Humanos , Lipoproteínas HDL/química , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Nanocompostos/química , Placa Amiloide/patologia
11.
Nanomedicine (Lond) ; 12(11): 1231-1242, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28593827

RESUMO

AIM: Based on the ability of apoptosis to induce immunological tolerance, liposomes were generated mimicking apoptotic cells, and they arrest autoimmunity in Type 1 diabetes. Our aim was to validate the immunotherapy in other autoimmune disease: multiple sclerosis. MATERIALS & METHODS: Phosphatidylserine-rich liposomes were loaded with disease-specific autoantigen. Therapeutic capability of liposomes was assessed in vitro and in vivo. RESULTS: Liposomes induced a tolerogenic phenotype in dendritic cells, and arrested autoimmunity, thus decreasing the incidence, delaying the onset and reducing the severity of experimental disease, correlating with an increase in a probably regulatory CD25+ FoxP3- CD4+ T-cell subset. CONCLUSION: This is the first work that confirms phosphatidylserine-liposomes as a powerful tool to arrest multiple sclerosis, demonstrating its relevance for clinical application.


Assuntos
Autoantígenos/administração & dosagem , Imunoterapia/métodos , Lipossomos/química , Esclerose Múltipla/terapia , Glicoproteína Mielina-Oligodendrócito/administração & dosagem , Peptídeos/administração & dosagem , Fosfatidilserinas/química , Animais , Autoantígenos/imunologia , Autoantígenos/uso terapêutico , Feminino , Camundongos Endogâmicos C57BL , Esclerose Múltipla/imunologia , Glicoproteína Mielina-Oligodendrócito/imunologia , Glicoproteína Mielina-Oligodendrócito/uso terapêutico , Peptídeos/imunologia , Peptídeos/uso terapêutico , Linfócitos T Reguladores/imunologia
12.
Sci Rep ; 7: 41441, 2017 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-28120922

RESUMO

Bacteriophages are promising therapeutic agents that can be applied to different stages of the commercial food chain. In this sense, bacteriophages can be orally administered to farm animals to protect them against intestinal pathogens. However, the low pH of the stomach, the activities of bile and intestinal tract enzymes limit the efficacy of the phages. This study demonstrates the utility of an alginate/CaCO3 encapsulation method suitable for bacteriophages with different morphologies and to yield encapsulation efficacies of ~100%. For the first time, a cocktail of three alginate/CaCO3-encapsulated bacteriophages was administered as oral therapy to commercial broilers infected with Salmonella under farm-like conditions. Encapsulation protects the bacteriophages against their destruction by the gastric juice. Phage release from capsules incubated in simulated intestinal fluid was also demonstrated, whereas encapsulation ensured sufficient intestinal retention of the phages. Moreover, the small size of the capsules (125-150 µm) enables their use in oral therapy and other applications in phage therapy. This study evidenced that a cocktail of the three alginate/CaCO3-encapsulated bacteriophages had a greater and more durable efficacy than a cocktail of the corresponding non-encapsulated phages in as therapy in broilers against Salmonella, one of the most common foodborne pathogen.


Assuntos
Alginatos/química , Carbonato de Cálcio/química , Composição de Medicamentos/métodos , Terapia por Fagos , Animais , Líquidos Corporais/química , Ceco/virologia , Galinhas , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Imagem Tridimensional , Salmonella/fisiologia , Salmonelose Animal
13.
Int J Nanomedicine ; 11: 3035-48, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27418824

RESUMO

BACKGROUND AND AIMS: Although the beneficial effects of statins on stroke have been widely demonstrated both in experimental studies and in clinical trials, the aim of this study is to prepare and characterize a new liposomal delivery system that encapsulates simvastatin to improve its delivery into the brain. MATERIALS AND METHODS: In order to select the optimal liposome lipid composition with the highest capacity to reach the brain, male Wistar rats were submitted to sham or transitory middle cerebral arterial occlusion (MCAOt) surgery and treated (intravenous [IV]) with fluorescent-labeled liposomes with different net surface charges. Ninety minutes after the administration of liposomes, the brain, blood, liver, lungs, spleen, and kidneys were evaluated ex vivo using the Xenogen IVIS(®) Spectrum imaging system to detect the load of fluorescent liposomes. In a second substudy, simvastatin was assessed upon reaching the brain, comparing free and encapsulated simvastatin (IV) administration. For this purpose, simvastatin levels in brain homogenates from sham or MCAOt rats at 2 hours or 4 hours after receiving the treatment were detected through ultra-high-protein liquid chromatography. RESULTS: Whereas positively charged liposomes were not detected in brain or plasma 90 minutes after their administration, neutral and negatively charged liposomes were able to reach the brain and accumulate specifically in the infarcted area. Moreover, neutral liposomes exhibited higher bioavailability in plasma 4 hours after being administered. The detection of simvastatin by ultra-high-protein liquid chromatography confirmed its ability to cross the blood-brain barrier, when administered either as a free drug or encapsulated into liposomes. CONCLUSION: This study confirms that liposome charge is critical to promote its accumulation in the brain infarct after MCAOt. Furthermore, simvastatin can be delivered after being encapsulated. Thus, simvastatin encapsulation might be a promising strategy to ensure that the drug reaches the brain, while increasing its bioavailability and reducing possible side effects.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Lipossomos/administração & dosagem , Sinvastatina/administração & dosagem , Acidente Vascular Cerebral/tratamento farmacológico , Animais , Disponibilidade Biológica , Barreira Hematoencefálica/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Isquemia Encefálica/tratamento farmacológico , Infarto da Artéria Cerebral Média , Rim/efeitos dos fármacos , Lipossomos/química , Lipossomos/metabolismo , Fígado/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Masculino , Ratos Wistar , Sinvastatina/química , Sinvastatina/farmacocinética , Sinvastatina/farmacologia , Baço/efeitos dos fármacos , Distribuição Tecidual
14.
PLoS One ; 10(6): e0127057, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26039878

RESUMO

INTRODUCTION: The development of new therapies to induce self-tolerance has been an important medical health challenge in type 1 diabetes. An ideal immunotherapy should inhibit the autoimmune attack, avoid systemic side effects and allow ß-cell regeneration. Based on the immunomodulatory effects of apoptosis, we hypothesized that apoptotic mimicry can help to restore tolerance lost in autoimmune diabetes. OBJECTIVE: To generate a synthetic antigen-specific immunotherapy based on apoptosis features to specifically reestablish tolerance to ß-cells in type 1 diabetes. METHODS: A central event on the surface of apoptotic cells is the exposure of phosphatidylserine, which provides the main signal for efferocytosis. Therefore, phosphatidylserine-liposomes loaded with insulin peptides were generated to simulate apoptotic cells recognition by antigen presenting cells. The effect of antigen-specific phosphatidylserine-liposomes in the reestablishment of peripheral tolerance was assessed in NOD mice, the spontaneous model of autoimmune diabetes. MHC class II-peptide tetramers were used to analyze the T cell specific response after treatment with phosphatidylserine-liposomes loaded with peptides. RESULTS: We have shown that phosphatidylserine-liposomes loaded with insulin peptides induce tolerogenic dendritic cells and impair autoreactive T cell proliferation. When administered to NOD mice, liposome signal was detected in the pancreas and draining lymph nodes. This immunotherapy arrests the autoimmune aggression, reduces the severity of insulitis and prevents type 1 diabetes by apoptotic mimicry. MHC class II tetramer analysis showed that peptide-loaded phosphatidylserine-liposomes expand antigen-specific CD4+ T cells in vivo. The administration of phosphatidylserine-free liposomes emphasizes the importance of phosphatidylserine in the modulation of antigen-specific CD4+ T cell expansion. CONCLUSIONS: We conclude that this innovative immunotherapy based on the use of liposomes constitutes a promising strategy for autoimmune diseases.


Assuntos
Autoantígenos/imunologia , Autoimunidade , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/imunologia , Fosfatidilserinas/uso terapêutico , Animais , Linfócitos T CD4-Positivos/imunologia , Diferenciação Celular , Citocinas/metabolismo , Células Dendríticas/imunologia , Imunoterapia , Injeções Intraperitoneais , Insulina/uso terapêutico , Lipossomos , Camundongos Endogâmicos NOD , Fenótipo
15.
Appl Environ Microbiol ; 81(14): 4841-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25956778

RESUMO

Bacteriophages UAB_Phi20, UAB_Phi78, and UAB_Phi87 were encapsulated in liposomes, and their efficacy in reducing Salmonella in poultry was then studied. The encapsulated phages had a mean diameter of 309 to 326 nm and a positive charge between +31.6 and +35.1 mV (pH 6.1). In simulated gastric fluid (pH 2.8), the titer of nonencapsulated phages decreased by 5.7 to 7.8 log units, whereas encapsulated phages were significantly more stable, with losses of 3.7 to 5.4 log units. The liposome coating also improved the retention of bacteriophages in the chicken intestinal tract. When cocktails of the encapsulated and nonencapsulated phages were administered to broilers, after 72 h the encapsulated phages were detected in 38.1% of the animals, whereas the nonencapsulated phages were present in only 9.5%. The difference was significant. In addition, in an in vitro experiment, the cecal contents of broilers promoted the release of the phages from the liposomes. In broilers experimentally infected with Salmonella, the daily administration of the two cocktails for 6 days postinfection conferred similar levels of protection against Salmonella colonization. However, once treatment was stopped, protection by the nonencapsulated phages disappeared, whereas that provided by the encapsulated phages persisted for at least 1 week, showing the enhanced efficacy of the encapsulated phages in protecting poultry against Salmonella over time. The methodology described here allows the liposome encapsulation of phages of different morphologies. The preparations can be stored for at least 3 months at 4°C and could be added to the drinking water and feed of animals.


Assuntos
Terapia Biológica , Doenças das Aves Domésticas/terapia , Salmonelose Animal/terapia , Fagos de Salmonella/química , Fagos de Salmonella/fisiologia , Salmonella/virologia , Animais , Terapia Biológica/instrumentação , Terapia Biológica/métodos , Galinhas , Lipossomos/química , Doenças das Aves Domésticas/microbiologia , Salmonella/fisiologia , Salmonelose Animal/microbiologia
16.
Chem Commun (Camb) ; 50(60): 8215-8, 2014 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-24930775

RESUMO

The presence of water-rich and water-lean nanodomains in a transparent, pressurized "water-acetone-CO2" mixture was revealed by Raman spectroscopy. This nano-structured liquid can be classified as a surfactant-free microemulsion-like system and has the capacity to dissolve hydrophobic compounds, such as ibuprofen, in the presence of large amounts of water. This finding opens new opportunities in the fields of confined reactions and material templating.


Assuntos
Acetona/química , Anti-Inflamatórios não Esteroides/química , Dióxido de Carbono/química , Ibuprofeno/química , Tensoativos/química , Água/química , Emulsões , Tamanho da Partícula , Solubilidade
17.
Vaccine ; 32(31): 3955-62, 2014 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-24837767

RESUMO

Herein we report the use of immunostimulant-loaded nanoliposomes (called NLcliposomes) as a strategy to protect fish against bacterial and/or viral infections. This work entailed developing a method for in vivo tracking of the liposomes administered to adult zebrafish that enables evaluation of their in vivo dynamics and characterisation of their tissue distribution. The NLc liposomes, which co-encapsulate poly(I:C) and LPS, accumulate in immune tissues and in immunologically relevant cells such as macrophages, as has been assessed in trout primary cell cultures. They protect zebrafish against otherwise lethal bacterial (Pseudomonas aeruginosa PAO1) and viral (Spring Viraemia of Carp Virus) infections regardless of whether they are administered by injection or by immersion, as demonstrated in a series of in vivo infection experiments with adult zebrafish. Importantly, protection was not achieved in fish that had been treated with empty liposomes or with a mixture of the free immunostimulants. Our findings indicate that stimulation of the innate immune system with co-encapsulated immunostimulants in nano-liposomes is a promising strategy to simultaneously improve the levels of protection against bacterial and viral infections in fish.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Lipossomos/imunologia , Nanopartículas/química , RNA de Cadeia Dupla/imunologia , Peixe-Zebra/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Doenças dos Peixes/prevenção & controle , Imunidade Inata , Lipopolissacarídeos/imunologia , Oncorhynchus , Poli I-C/imunologia
18.
PLoS One ; 8(10): e76338, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24204616

RESUMO

Development of novel systems of vaccine delivery is a growing demand of the aquaculture industry. Nano- and micro- encapsulation systems are promising tools to achieve efficient vaccines against orphan vaccine fish diseases. In this context, the use of liposomal based-nanocarriers has been poorly explored in fish; although liposomal nanocarriers have successfully been used in other species. Here, we report a new ∼125 nm-in-diameter unilamellar liposome-encapsulated immunostimulant cocktail containing crude lipopolysaccharide (LPS) from E. coli and polyinosinic:polycytidylic acid [poly (I:C)], a synthetic analog of dsRNA virus, aiming to be used as a non-specific vaccine nanocarrier in different fish species. This liposomal carrier showed high encapsulation efficiencies and low toxicity not only in vitro using three different cellular models but also in vivo using zebrafish embryos and larvae. We showed that such liposomal LPS-dsRNA cocktail is able to enter into contact with zebrafish hepatocytes (ZFL cell line) and trout macrophage plasma membranes, being preferentially internalized through caveolae-dependent endocytosis, although clathrin-mediated endocytosis in ZFL cells and macropinocytocis in macrophages also contribute to liposome uptake. Importantly, we also demonstrated that this liposomal LPS-dsRNA cocktail elicits a specific pro-inflammatory and anti-viral response in both zebrafish hepatocytes and trout macrophages. The design of a unique delivery system with the ability to stimulate two potent innate immunity pathways virtually present in all fish species represents a completely new approach in fish health.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Sistemas de Liberação de Medicamentos , Imunidade Inata , Lipopolissacarídeos/administração & dosagem , Lipossomos , Nanocompostos , RNA de Cadeia Dupla/administração & dosagem , Adjuvantes Imunológicos/química , Adjuvantes Imunológicos/toxicidade , Animais , Linhagem Celular , Endocitose , Peixes , Lipopolissacarídeos/química , Lipopolissacarídeos/imunologia , Lipossomos/química , Macrófagos/imunologia , Nanocompostos/química , Nanocompostos/toxicidade , Poli I-C/química , RNA de Cadeia Dupla/química , RNA de Cadeia Dupla/imunologia , Vacinas , Peixe-Zebra
19.
Langmuir ; 29(22): 6519-28, 2013 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-23647396

RESUMO

Thermodynamically stable nanovesicle structures are of high interest for academia and industry in a wide variety of application fields, ranging from preparation of nanomaterials to nanomedicine. Here, we show the ability of quaternary ammonium surfactants and sterols to self-assemble, forming stable amphiphilic bimolecular building-blocks with the appropriate structural characteristics to form in aqueous phases, closed bilayers, named quatsomes, with outstanding stability, with time and temperature. The molecular self-assembling of cholesterol and surfactant cetyltrimethylammonium bromide (CTAB) was studied by quasi-elastic light scattering, cryogenic transmission electron microscopy, turbidity (optical density) measurements, and molecular dynamic simulations with atomistic detail, upon varying the cholesterol-to-surfactant molar ratio. As pure species, CTAB forms micelles and insoluble cholesterol forms crystals in water. However, our molecular dynamic simulations reveal that the synergy between CTAB and cholesterol molecules makes them self-assemble into bimolecular amphiphiles and then into bilayers in the presence of water. These bilayers have the same structure of those formed by double-tailed unimolecular amphiphiles.


Assuntos
Compostos de Cetrimônio/química , Colesterol/química , Bicamadas Lipídicas/química , Nanoestruturas/química , Tensoativos/química , Cetrimônio , Micelas , Microscopia Eletrônica de Transmissão , Simulação de Dinâmica Molecular , Nanoestruturas/ultraestrutura , Temperatura Ambiente , Termodinâmica , Água
20.
Nat Chem ; 5(3): 203-11, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23422562

RESUMO

Metal-organic frameworks (MOFs) are among the most attractive porous materials known today. Their miniaturization to the nanoscale--into nanoMOFs--is expected to serve myriad applications from drug delivery to membranes, to open up novel avenues to more traditional storage and catalysis applications, and to enable the creation of sophisticated superstructures. Here, we report the use of spray-drying as a versatile methodology to assemble nanoMOFs, yielding spherical hollow superstructures with diameters smaller than 5 µm. This strategy conceptually mimics the emulsions used by chemists to confine the synthesis of materials, but does not require secondary immiscible solvents or surfactants. We demonstrate that the resulting spherical, hollow superstructures can be processed into stable colloids, whose disassembly by sonication affords discrete, homogeneous nanoMOFs. This spray-drying strategy enables the construction of multicomponent MOF superstructures, and the encapsulation of guest species within these superstructures. We anticipate that this will provide new routes to capsules, reactors and composite materials.


Assuntos
Portadores de Fármacos/síntese química , Nanopartículas Metálicas/química , Metais/química , Nanotecnologia/métodos , Compostos Organometálicos/síntese química , Portadores de Fármacos/química , Nanoporos , Nanotecnologia/instrumentação , Compostos Organometálicos/química
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