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1.
Int J Pharm ; 657: 124144, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38653342

RESUMO

New drugs and technologies are continuously developed to improve the efficacy and minimize the critical side effects of cancer treatments. The present investigation focuses on the development of a liposomal formulation for Idelalisib, a small-molecule kinase inhibitor approved for the treatment of lymphoid malignancies. Idelalisib is a potent and selective antitumor agent, but it is not indicated nor recommended for first-line treatment due to fatal and serious toxicities. Herein, liposomes are proposed as a delivery tool to improve the therapeutic profile of Idelalisib. Specifically, PEGylated liposomes were prepared, and their physicochemical and technological features were investigated. Light-scattering spectroscopy and cryo-transmission electron microscopy revealed nanosized unilamellar vesicles, which were proved to be stable in storage and in simulated biological fluids. The cytotoxicity of the liposome formulation was investigated in a human non-Hodgkin's lymphoma B cell line. Idelalisib was able to induce death of tumor cells if delivered by the nanocarrier system at increased efficacy. These findings suggest that combining Idelalisib and nanotechnologies may be a powerful strategy to increase the antitumor efficacy of the drug.


Assuntos
Antineoplásicos , Lipossomos , Polietilenoglicóis , Purinas , Quinazolinonas , Humanos , Purinas/química , Purinas/administração & dosagem , Purinas/farmacologia , Quinazolinonas/química , Quinazolinonas/administração & dosagem , Quinazolinonas/farmacologia , Polietilenoglicóis/química , Linhagem Celular Tumoral , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Antineoplásicos/química , Sobrevivência Celular/efeitos dos fármacos , Linfoma de Células B/tratamento farmacológico
2.
Int J Pharm ; 643: 123195, 2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37394159

RESUMO

Artemisinin, curcumin or quercetin, alone or in combination, were loaded in nutriosomes, special phospholipid vesicles enriched with Nutriose FM06®, a soluble dextrin with prebiotic activity, that makes these vesicles suitable for oral delivery. The resulting nutriosomes were sized between 93 and 146 nm, homogeneously dispersed, and had slightly negative zeta potential (around -8 mV). To improve their shelf life and storability over time, vesicle dispersions were freeze-dried and stored at 25 °C. Results confirmed that their main physico-chemical characteristics remained unchanged over a period of 12 months. Additionally, their size and polydispersity index did not undergo any significant variation after dilution with solutions at different pHs (1.2 and 7.0) and high ionic strength, mimicking the harsh conditions of the stomach and intestine. An in vitro study disclosed the delayed release of curcumin and quercetin from nutriosomes (∼53% at 48 h) while artemisinin was quickly released (∼100% at 48 h). Cytotoxicity assays using human colon adenocarcinoma cells (Caco-2) and human umbilical vein endothelial cells (HUVECs) proved the high biocompatibility of the prepared formulations. Finally, in vitro antimalarial activity tests, assessed against the 3D7 strain of Plasmodium falciparum, confirmed the effectiveness of nutriosomes in the delivery of curcumin and quercetin, which can be used as adjuvants in the antimalaria treatment. The efficacy of artemisinin was also confirmed but not improved. Overall results proved the possible use of these formulations as an accompanying treatment of malaria infections.


Assuntos
Adenocarcinoma , Antimaláricos , Artemisininas , Neoplasias do Colo , Curcumina , Malária , Humanos , Quercetina/farmacologia , Quercetina/uso terapêutico , Lipossomos , Curcumina/farmacologia , Células CACO-2 , Células Endoteliais , Malária/tratamento farmacológico , Antimaláricos/farmacologia , Artemisininas/uso terapêutico , Adjuvantes Imunológicos/uso terapêutico , Adjuvantes Farmacêuticos
3.
Brain Commun ; 4(5): fcac243, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36267327

RESUMO

Alzheimer's disease and Type 2 diabetes are pathological processes associated to ageing. Moreover, there are evidences supporting a mechanistic link between Alzheimer's disease and insulin resistance (one of the first hallmarks of Type 2 diabetes). Regarding Alzheimer's disease, amyloid ß-peptide aggregation into ß-sheets is the main hallmark of Alzheimer's disease. At monomeric state, amyloid ß-peptide is not toxic but its function in brain, if any, is unknown. Here we show, by in silico study, that monomeric amyloid ß-peptide 1-40 shares the tertiary structure with insulin and is thereby able to bind and activate insulin receptor. We validated this prediction experimentally by treating human neuroblastoma cells with increasing concentrations of monomeric amyloid ß-peptide 1-40. Our results confirm that monomeric amyloid ß-peptide 1-40 activates insulin receptor autophosphorylation, triggering downstream enzyme phosphorylations and the glucose Transporter 4 translocation to the membrane. On the other hand, neuronal insulin resistance is known to be associated to Alzheimer's disease since early stages. We thus modelled the docking of oligomeric amyloid ß-peptide 1-40 to insulin receptor. We found that oligomeric amyloid ß-peptide 1-40 blocks insulin receptor, impairing its activation. It was confirmed in vitro by observing the lack of insulin receptor autophosphorylation, and also the impairment of insulin-induced intracellular enzyme activations and the glucose Transporter 4 translocation to the membrane. By biological system analysis, we have carried out a mathematical model recapitulating the process that turns amyloid ß-peptide binding to insulin receptor from the physiological to the pathophysiological regime. Our results suggest that monomeric amyloid ß-peptide 1-40 contributes to mimic insulin effects in the brain, which could be good when neurons have an extra requirement of energy beside the well-known protective effects on insulin intracellular signalling, while its accumulation and subsequent oligomerization blocks the insulin receptor producing insulin resistance and compromising neuronal metabolism and protective pathways.

4.
Nanomaterials (Basel) ; 11(4)2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33810420

RESUMO

In this work beclomethasone dipropionate was loaded into liposomes and hyalurosomes modified with mucin to improve the ability of the payload to counteract the oxidative stress and involved damages caused by cigarette smoke in the airway. The vesicles were prepared by dispersing all components in the appropriate vehicle and sonicating them, thus avoiding the use of organic solvents. Unilamellar and bilamellar vesicles small in size (~117 nm), homogeneously dispersed (polydispersity index lower than 0.22) and negatively charged (~-11 mV), were obtained. Moreover, these vesicle dispersions were stable for five months at room temperature (~25 °C). In vitro studies performed using the Next Generation Impactor confirmed the suitability of the formulations to be nebulized as they were capable of reaching the last stages of the impactor that mimic the deeper airways, thus improving the deposition of beclomethasone in the target site. Further, biocompatibility studies performed by using 16HBE bronchial epithelial cells confirmed the high biocompatibility and safety of all the vesicles. Among the tested formulations, only mucin-hyalurosomes were capable of effectively counteracting the production of reactive oxygen species (ROS) induced by cigarette smoke extract, suggesting that this formulation may represent a promising tool to reduce the damaging effects of cigarette smoke in the lung tissues, thus reducing the pathogenesis of cigarette smoke-associated diseases such as chronic obstructive pulmonary disease, emphysema, and cancer.

5.
Int J Pharm ; 592: 120083, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33197563

RESUMO

Resveratrol and artemisinin, two naturally occurring compounds with a wide range of biological activities, have been reported to exert antitumor effects against several types of cancer. In this work, Eudragit-coated liposomes were developed to safely transport resveratrol and artemisinin through the gastrointestinal tract and target the intestine. The physico-chemical properties of the Eudragit-coated liposomes were assessed by light scattering and cryogenic transmission electron microscopy. Nanosized (around 100 nm), spherical or elongated, unilamellar vesicles were produced. The protective effect of the Eudragit coating was confirmed by assessing the physical stability of the vesicles in fluids mimicking the gastrointestinal environment. Furthermore, the vesicles were found to exert a pro-oxidant activity in intestinal adenocarcinoma cells, which resulted in a marked mortality due to the generation of reactive oxygen species (ROS). A time- and dose-dependent cell growth inhibitory effect was detected, with elevated ROS levels when resveratrol and artemisinin were combined. Therefore, the proposed formulations may represent a valuable means to counteract intestinal tumor growth.


Assuntos
Artemisininas , Neoplasias Intestinais , Humanos , Lipossomos , Ácidos Polimetacrílicos , Resveratrol
6.
Colloids Surf B Biointerfaces ; 193: 111146, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32485579

RESUMO

Grape extract-loaded fibre-enriched vesicles, nutriosomes, were prepared by combining antioxidant extracts obtained from grape pomaces and a prebiotic, soluble fibre (Nutriose®FM06). The nutriosomes were small in size (from ∼140 to 260 nm), homogeneous (polydispersity index < 0.2) and highly negative (∼ -79 mV). The vesicles were highly stable during 12 months of storage at 25 °C. When diluted with warmed (37 °C) acidic medium (pH 1.2) of high ionic strength, the vesicles only displayed an increase of the mean diameter and a low release of the extract, which were dependent on Nutriose concentration. The formulations were highly biocompatible and able to protect intestinal cells (Caco-2) from oxidative stress damage. In vivo results underlined that the composition of mouse microbiota was not affected by the vesicular formulations. Overall results support the potential application of grape nutriosomes as an alternative strategy for the protection of the intestinal tract.


Assuntos
Antioxidantes/farmacologia , Fibras na Dieta/farmacologia , Intestinos/efeitos dos fármacos , Prebióticos/administração & dosagem , Resíduos/análise , Vinho/análise , Animais , Antioxidantes/administração & dosagem , Antioxidantes/isolamento & purificação , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Fibras na Dieta/administração & dosagem , Feminino , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Intestinos/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Propriedades de Superfície
7.
Artigo em Inglês | MEDLINE | ID: mdl-32284383

RESUMO

The rapid evolution of resistance in the malaria parasite to every single drug developed against it calls for the urgent identification of new molecular targets. Using a stain specific for the detection of intracellular amyloid deposits in live cells, we have detected the presence of abundant protein aggregates in Plasmodium falciparum blood stages and female gametes cultured in vitro, in the blood stages of mice infected by Plasmodium yoelii, and in the mosquito stages of the murine malaria species Plasmodium berghei Aggregated proteins could not be detected in early rings, the parasite form that starts the intraerythrocytic cycle. A proteomics approach was used to pinpoint actual aggregating polypeptides in functional P. falciparum blood stages, which resulted in the identification of 369 proteins, with roles particularly enriched in nuclear import-related processes. Five aggregation-prone short peptides selected from this protein pool exhibited different aggregation propensity according to Thioflavin-T fluorescence measurements, and were observed to form amorphous aggregates and amyloid fibrils in transmission electron microscope images. The results presented suggest that generalized protein aggregation might have a functional role in malaria parasites. Future antimalarial strategies based on the upsetting of the pathogen's proteostasis and therefore affecting multiple gene products could represent the entry to new therapeutic approaches.


Assuntos
Parasitos , Animais , Feminino , Camundongos , Plasmodium berghei , Plasmodium falciparum , Agregados Proteicos , Proteínas de Protozoários/genética
8.
Front Pharmacol ; 10: 1064, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31611785

RESUMO

Understanding how polyprotic compounds distribute within liposome (LP) suspensions is of major importance to design effective drug delivery strategies. Advances in this research field led to the definition of LP-based active drug encapsulation methods driven by transmembrane pH gradients with evidenced efficacy in the management of cancer and infectious diseases. An accurate modeling of membrane-solution drug partitioning is also fundamental when designing drug delivery systems for poorly endocytic cells, such as red blood cells (RBCs), in which the delivered payloads rely mostly on the passive diffusion of drug molecules across the cell membrane. Several experimental models have been proposed so far to predict the partitioning of polyprotic basic/acid drugs in artificial membranes. Nevertheless, the definition of a model in which the membrane-solution partitioning of each individual drug microspecies is studied relative to each other is still a topic of ongoing research. We present here a novel experimental approach based on mathematical modeling of drug encapsulation efficiency (EE) data in liposomal systems by which microspecies-specific partition coefficients are reported as a function of pH and phospholipid compositions replicating the RBC membrane in a simple and highly translatable manner. This approach has been applied to the study of several diprotic basic antimalarials of major clinical importance (quinine, primaquine, tafenoquine, quinacrine, and chloroquine) describing their respective microspecies distribution in phosphatidylcholine-LP suspensions. Estimated EE data according to the model described here closely fitted experimental values with no significant differences obtained in 75% of all pH/lipid composition-dependent conditions assayed. Additional applications studied include modeling drug EE in LPs in response to transmembrane pH gradients and lipid bilayer asymmetric charge, conditions of potential interest reflected in our previously reported RBC-targeted antimalarial nanotherapeutics.

9.
Comput Struct Biotechnol J ; 17: 963-971, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31360335

RESUMO

Alzheimer's disease (AD) is a neurodegenerative process characterized by the accumulation of extracellular deposits of amyloid ß-peptide (Aß), which induces neuronal death. Monomeric Aß is not toxic but tends to aggregate into ß-sheets that are neurotoxic. Therefore to prevent or delay AD onset and progression one of the main therapeutic approaches would be to impair Aß assembly into oligomers and fibrils and to promote disaggregation of the preformed aggregate. Albumin is the most abundant protein in the cerebrospinal fluid and it was reported to bind Aß impeding its aggregation. In a previous work we identified a 35-residue sequence of clusterin, a well-known protein that binds Aß, that is highly similar to the C-terminus (CTerm) of albumin. In this work, the docking experiments show that the average binding free energy of the CTerm-Aß1-42 simulations was significantly lower than that of the clusterin-Aß1-42 binding, highlighting the possibility that the CTerm retains albumin's binding properties. To validate this observation, we performed in vitro structural analysis of soluble and aggregated 1 µM Aß1-42 incubated with 5 µM CTerm, equimolar to the albumin concentration in the CSF. Reversed-phase chromatography and electron microscopy analysis demonstrated a reduction of Aß1-42 aggregates when the CTerm was present. Furthermore, we treated a human neuroblastoma cell line with soluble and aggregated Aß1-42 incubated with CTerm obtaining a significant protection against Aß-induced neurotoxicity. These in silico and in vitro data suggest that the albumin CTerm is able to impair Aß aggregation and to promote disassemble of Aß aggregates protecting neurons.

10.
Int J Pharm ; 565: 64-69, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31071415

RESUMO

Quercetin, a natural polyphenol with strong antioxidant activity, was loaded in Eudragit-coated liposomes conceived for intestinal delivery. Eudragit was used to form a protective shell on the surface of liposomes to resist gastric environment and allow the delivery of quercetin to the intestine. The physico-chemical properties of the liposomes were assessed by light scattering and cryogenic transmission electron microscopy. Small, spherical, uni- and bilamellar liposomes were produced, with the presence of multilamellar structures in Eudragit-coated liposomes. The Eudragit coating increased the physical stability of the vesicular system in fluids mimicking the gastrointestinal environment. Further, the incorporation of quercetin in the vesicular system did not affect its intrinsic antioxidant activity, as DPPH radical was almost completely inhibited, and the vesicles were also capable of ensuring optimal protection against oxidative stress in human intestinal cells by reducing reactive oxygen species (ROS) production. The proposed approach based on quercetin vesicular formulations may be of value in the treatment of pathological conditions associated with intestinal oxidative stress.


Assuntos
Antioxidantes/administração & dosagem , Ácidos Polimetacrílicos/administração & dosagem , Quercetina/administração & dosagem , Antioxidantes/química , Compostos de Bifenilo/química , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Células HT29 , Humanos , Mucosa Intestinal/metabolismo , Lipossomos , Picratos/química , Ácidos Polimetacrílicos/química , Quercetina/química , Espécies Reativas de Oxigênio/metabolismo
11.
Eur J Med Chem ; 152: 489-514, 2018 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-29754074

RESUMO

Design, synthesis, structure-activity relationship, cytotoxicity studies, in silico drug-likeness, genotoxicity screening, and in vivo studies of new 1-aryl-3-substituted propanol derivatives led to the identification of nine compounds with promising in vitro (55, 56, 61, 64, 66, and 70-73) and in vivo (66 and 72) antimalarial profiles against Plasmodium falciparum and Plasmodium berghei. Compounds 55, 56, 61, 64, 66 and 70-73 exhibited potent antiplasmodial activity against chloroquine-resistant strain FCR-3 (IC50s < 0.28 µM), and compounds 55, 56, 64, 70, 71, and 72 showed potent biological activity in chloroquine-sensitive and multidrug-resistant strains (IC50s < 0.7 µM for 3D7, D6, FCR-3 and C235). All of these compounds share appropriate drug-likeness profiles and adequate selectivity indexes (77 < SI < 184) as well as lack genotoxicity. In vivo efficacy tests in a mouse model showed compounds 66 and 72 to be promising candidates as they exhibited significant parasitemia reductions of 96.4% and 80.4%, respectively. Additional studies such as liver stage and sporogony inhibition, target exploration of heat shock protein 90 of P. falciparum, targeted delivery by immunoliposomes, and enantiomer characterization were performed and strongly reinforce the hypothesis of 1-aryl-3-substituted propanol derivatives as promising antimalarial compounds.


Assuntos
Antimaláricos/farmacologia , Sistemas de Liberação de Medicamentos , Parasitemia/tratamento farmacológico , Plasmodium berghei/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Propanóis/farmacologia , Animais , Antimaláricos/síntese química , Antimaláricos/química , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Hep G2 , Humanos , Camundongos , Estrutura Molecular , Parasitemia/parasitologia , Testes de Sensibilidade Parasitária , Plasmodium berghei/crescimento & desenvolvimento , Plasmodium falciparum/crescimento & desenvolvimento , Propanóis/síntese química , Propanóis/química , Relação Estrutura-Atividade
12.
Int J Mol Sci ; 19(5)2018 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-29734652

RESUMO

Curcumin is an antimalarial compound easy to obtain and inexpensive, having shown little toxicity across a diverse population. However, the clinical use of this interesting polyphenol has been hampered by its poor oral absorption, extremely low aqueous solubility and rapid metabolism. In this study, we have used the anionic copolymer Eudragit® S100 to assemble liposomes incorporating curcumin and containing either hyaluronan (Eudragit-hyaluronan liposomes) or the water-soluble dextrin Nutriose® FM06 (Eudragit-nutriosomes). Upon oral administration of the rehydrated freeze-dried nanosystems administered at 25/75 mg curcumin·kg−1·day−1, only Eudragit-nutriosomes improved the in vivo antimalarial activity of curcumin in a dose-dependent manner, by enhancing the survival of all Plasmodium yoelii-infected mice up to 11/11 days, as compared to 6/7 days upon administration of an equal dose of the free compound. On the other hand, animals treated with curcumin incorporated in Eudragit-hyaluronan liposomes did not live longer than the controls, a result consistent with the lower stability of this formulation after reconstitution. Polymer-lipid nanovesicles hold promise for their development into systems for the oral delivery of curcumin-based antimalarial therapies.


Assuntos
Curcumina/administração & dosagem , Sistemas de Liberação de Medicamentos , Lipossomos/administração & dosagem , Malária/tratamento farmacológico , Administração Oral , Animais , Antimaláricos/administração & dosagem , Antimaláricos/química , Curcumina/química , Humanos , Lipossomos/química , Malária/parasitologia , Camundongos , Nanopartículas/administração & dosagem , Nanopartículas/química , Plasmodium yoelii/efeitos dos fármacos , Plasmodium yoelii/patogenicidade
13.
Int J Pharm ; 538(1-2): 40-47, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29294324

RESUMO

The present investigation reports the development of PEG-modified liposomes for the delivery of naturally occurring resveratrol. PEG-modified liposomes were prepared by direct sonication of the phospholipid aqueous dispersion, in the presence of two PEG-surfactants. Small, spherical, unilamellar vesicles were produced, as demonstrated by light scattering, cryo-TEM, and SAXS. The aging of the vesicles was assessed by using the Turbiscan® technology, and their physical stability was evaluated in vitro in simulated body fluids, results showing that the key features of the liposomes were preserved. The biocompatibility of the formulations was demonstrated in an ex vivo model of hemolysis in human erythrocytes. Further, the incorporation of resveratrol in PEG-modified liposomes did not affect its intrinsic antioxidant activity, as DPPH radical was almost completely inhibited, and the vesicles were also able to ensure an optimal protection against oxidative stress in an ex vivo human erythrocytes-based model. Therefore, the proposed PEG-modified liposomes, which were prepared by a simple and reliable method, represent an interesting approach to safely deliver resveratrol, ensuring the preservation of the carrier structural integrity in the biological fluids, and the antioxidant efficacy of the polyphenol to be exploited against oxidative stress associated with cancer.


Assuntos
Antioxidantes/administração & dosagem , Sistemas de Liberação de Medicamentos , Polietilenoglicóis/química , Estilbenos/administração & dosagem , Antioxidantes/química , Antioxidantes/farmacologia , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Estabilidade de Medicamentos , Difusão Dinâmica da Luz , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Sequestradores de Radicais Livres/administração & dosagem , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Hemólise/efeitos dos fármacos , Humanos , Lipossomos , Estresse Oxidativo/efeitos dos fármacos , Fosfolipídeos/química , Resveratrol , Estilbenos/química , Estilbenos/farmacologia , Tensoativos/química
14.
Nanomedicine (Lond) ; 12(14): 1727-1744, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28635544

RESUMO

Heparin is one of the oldest drugs, which nevertheless remains in widespread clinical use as an inhibitor of blood coagulation. The history of its identification a century ago unfolded amid one of the most fascinating scientific controversies turning around the distribution of credit for its discovery. The composition, purification and structure-function relationship of this naturally occurring glycosaminoglycan regarding its classical role as anticoagulant will be dealt with before proceeding to discuss its therapeutic potential in, among other, inflammatory and infectious disease, cancer treatment, cystic fibrosis and Alzheimer's disease. The first bibliographic reference hit using the words 'nanomedicine' and 'heparin' is as recent as 2008. Since then, nanomedical applications of heparin have experienced an exponential growth that will be discussed in detail, with particular emphasis on its antimalarial activity. Some of the most intriguing potential applications of heparin nanomedicines will be exposed, such as those contemplating the delivery of drugs to the mosquito stages of malaria parasites.


Assuntos
Anticoagulantes/uso terapêutico , Antimaláricos/uso terapêutico , Heparina/uso terapêutico , Malária/tratamento farmacológico , Animais , Anticoagulantes/farmacologia , Antimaláricos/farmacologia , Reposicionamento de Medicamentos/métodos , Heparina/farmacologia , Humanos , Nanomedicina/métodos
15.
Carbohydr Polym ; 157: 1853-1861, 2017 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-27987905

RESUMO

In the present work, quercetin and resveratrol, natural polyphenols with strong antioxidant and anti-inflammatory properties, were co-loaded in polymer-associated liposomes conceived for oral delivery, by exploiting the potential of pH-sensitive succinyl-chitosan. Chitosan was succinylated, characterized by Nuclear Magnetic Resonance spectroscopy and Gel Permeation Chromatography, and used to form a protective shell on the surface of liposomes. The physico-chemical properties of the succinyl-chitosan liposomes were assessed by light scattering, zeta potential, cryogenic transmission electron microscopy, and small angle X-ray scattering. Small, spherical, uni- and bilamellar vesicles were produced. The succinyl-chitosan shell increased not only the physical stability of the vesicular system, as demonstrated by accelerated stability tests, but also the release of the polyphenols to a greater extent at pH 7.0, mimicking the intestinal environment. The proposed approach based on polyphenol vesicular formulations may be of value in the treatment of pre-cancerous/cancerous intestinal conditions associated with inflammation and oxidative stress.


Assuntos
Quitosana , Portadores de Fármacos , Lipossomos , Quercetina/administração & dosagem , Estilbenos/administração & dosagem , Tamanho da Partícula , Resveratrol
16.
Int J Pharm ; 513(1-2): 153-163, 2016 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-27609664

RESUMO

The present investigation reports the development of liposomes for the co-delivery of naturally occurring polyphenols, namely quercetin and resveratrol. Small, spherical, uni/bilamellar vesicles were produced, as demonstrated by light scattering, cryo-TEM, SAXS. The incorporation of quercetin and resveratrol in liposomes did not affect their intrinsic antioxidant activity, as DPPH radical was almost completely inhibited. The cellular uptake of the polyphenols was higher when they were formulated in liposomes, and especially when co-loaded rather than as single agents, which resulted in a superior ability to scavenge ROS in fibroblasts. The in vivo efficacy of the polyphenols in liposomes was assessed in a mouse model of skin lesion. The topical administration of liposomes led to a remarkable amelioration of the tissue damage, with a significant reduction of oedema and leukocyte infiltration. Therefore, the proposed approach based on polyphenol vesicular formulation may be of value in the treatment of inflammation/oxidative stress associated with pre-cancerous/cancerous skin lesions.


Assuntos
Antioxidantes/administração & dosagem , Sistemas de Liberação de Medicamentos , Quercetina/administração & dosagem , Estilbenos/administração & dosagem , Administração Tópica , Animais , Modelos Animais de Doenças , Combinação de Medicamentos , Difusão Dinâmica da Luz , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Inflamação/tratamento farmacológico , Inflamação/patologia , Lipossomos , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Quercetina/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Resveratrol , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/patologia , Estilbenos/farmacologia
17.
Future Sci OA ; 1(2): FSO43, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28031872

RESUMO

The main therapeutic and prophylactic tools against malaria have been locked for more than a century in the classical approaches of using drugs targeting metabolic processes of the causing agent, the protist Plasmodium spp., and of designing vaccines against chosen antigens found on the parasite's surface. Given the extraordinary resources exhibited by Plasmodium to escape these traditional strategies, which have not been able to free humankind from the scourge of malaria despite much effort invested in them, new concepts have to be explored in order to advance toward eradication of the disease. In this context, amyloid-forming proteins and peptides found in the proteome of the pathogen should perhaps cease being regarded as mere anomalous molecules. Their likely functionality in the pathophysiology of Plasmodium calls for attention being paid to them as a possible Achilles' heel of malaria. Here we will give an overview of Plasmodium-encoded amyloid-forming polypeptides as potential therapeutic targets and toxic elements, particularly in relation to cerebral malaria and the blood-brain barrier function. We will also discuss the recent finding that the genome of the parasite contains an astonishingly high proportion of prionogenic domains.

18.
Mol Membr Biol ; 31(5): 152-67, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25046533

RESUMO

The blood-brain barrier (BBB) is constituted by a specialized vascular endothelium that interacts directly with astrocytes, neurons and pericytes. It protects the brain from the molecules of the systemic circulation but it has to be overcome for the proper treatment of brain cancer, psychiatric disorders or neurodegenerative diseases, which are dramatically increasing as the population ages. In the present work we have revised the current knowledge on the cellular structure of the BBB and the different procedures utilized currently and those proposed to cross it. Chemical modifications of the drugs, such as increasing their lipophilicity, turn them more prone to be internalized in the brain. Other mechanisms are the use of molecular tools to bind the drugs such as small immunoglobulins, liposomes or nanoparticles that will act as Trojan Horses favoring the drug delivery in brain. This fusion of the classical pharmacology with nanotechnology has opened a wide field to many different approaches with promising results to hypothesize that BBB will not be a major problem for the new generation of neuroactive drugs. The present review provides an overview of all state-of-the-art of the BBB structure and function, as well as of the classic strategies and these appeared in recent years to deliver drugs into the brain for the treatment of Central Nervous System (CNS) diseases.


Assuntos
Barreira Hematoencefálica/ultraestrutura , Encéfalo/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Endotélio Vascular/ultraestrutura , Barreira Hematoencefálica/metabolismo , Encéfalo/patologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Endotélio Vascular/efeitos dos fármacos , Humanos , Lipossomos/administração & dosagem , Transtornos Mentais/tratamento farmacológico , Transtornos Mentais/patologia , Nanotecnologia , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/patologia
19.
Int J Parasitol Drugs Drug Resist ; 4(1): 28-36, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24596666

RESUMO

S-adenosyl-l-methionine decarboxylase (AdoMetDC) in the polyamine biosynthesis pathway has been identified as a suitable drug target in Plasmodium falciparum parasites, which causes the most lethal form of malaria. Derivatives of an irreversible inhibitor of this enzyme, 5'-{[(Z)-4-amino-2-butenyl]methylamino}-5'-deoxyadenosine (MDL73811), have been developed with improved pharmacokinetic profiles and activity against related parasites, Trypanosoma brucei. Here, these derivatives were assayed for inhibition of AdoMetDC from P. falciparum parasites and the methylated derivative, 8-methyl-5'-{[(Z)-4-aminobut-2-enyl]methylamino}-5'-deoxyadenosine (Genz-644131) was shown to be the most active. The in vitro efficacy of Genz-644131 was markedly increased by nanoencapsulation in immunoliposomes, which specifically targeted intraerythrocytic P. falciparum parasites.

20.
J Alzheimers Dis ; 40(3): 643-57, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24503620

RESUMO

Glycation and nitrotyrosination are pathological posttranslational modifications that make proteins prone to losing their physiological properties. Since both modifications are increased in Alzheimer's disease (AD) due to amyloid-ß peptide (Aß) accumulation, we have studied their effect on albumin, the most abundant protein in cerebrospinal fluid and blood. Brain and plasmatic levels of glycated and nitrated albumin were significantly higher in AD patients than in controls. In vitro turbidometry and electron microscopy analyses demonstrated that glycation and nitrotyrosination promote changes in albumin structure and biochemical properties. Glycated albumin was more resistant to proteolysis and less uptake by hepatoma cells occurred. Glycated albumin also reduced the osmolarity expected for a solution containing native albumin. Both glycation and nitrotyrosination turned albumin cytotoxic in a cell type-dependent manner for cerebral and vascular cells. Finally, of particular relevance to AD, these modified albumins were significantly less effective in avoiding Aß aggregation than native albumin. In summary, nitrotyrosination and especially glycation alter albumin structural and biochemical properties, and these modifications might contribute for the progression of AD.


Assuntos
Albuminas/metabolismo , Doença de Alzheimer , Peptídeos beta-Amiloides/metabolismo , Fragmentos de Peptídeos/metabolismo , Processamento de Proteína Pós-Traducional/fisiologia , Tirosina/análogos & derivados , Idoso , Albuminas/efeitos dos fármacos , Albuminas/farmacologia , Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/patologia , Encéfalo/citologia , Encéfalo/metabolismo , Encéfalo/patologia , Células Cultivadas , Relação Dose-Resposta a Droga , Células Endoteliais/efeitos dos fármacos , Feminino , Glicosilação , Humanos , Masculino , Molsidomina/análogos & derivados , Molsidomina/farmacologia , Neurônios/efeitos dos fármacos , Agregados Proteicos/fisiologia , Tripsina/farmacologia , Tirosina/metabolismo , Proteínas tau/metabolismo
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