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1.
Endoscopy ; 54(9): 904-915, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35913069

RESUMO

The European Society of Gastrointestinal Endoscopy (ESGE) presents a short list of performance measures for colonoscopy in inflammatory bowel disease (IBD) patients. Current performance measures for colonoscopy mainly focus on detecting (pre)malignant lesions. However, these performance measures are not relevant for all colonoscopy indications in IBD patients. Therefore, our aim was to provide endoscopy services across Europe and other interested countries with a tool for quality monitoring and improvement in IBD colonoscopy. Eight key performance measures and one minor performance measure were recommended for measurement and evaluation in daily endoscopy practice.


Assuntos
Doenças Inflamatórias Intestinais , Melhoria de Qualidade , Colonoscopia , Endoscopia Gastrointestinal , Europa (Continente) , Humanos , Doenças Inflamatórias Intestinais/diagnóstico por imagem
2.
Bioconjug Chem ; 32(4): 729-745, 2021 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-33689293

RESUMO

Ultrasmall nanoparticles (US-NPs; <20 nm in hydrodynamic size) are now included in a variety of pharmacological and cosmetic products, and new technologies are needed to detect at high sensitivity the passage of small doses of these products across biological barriers such as the skin. In this work, a diffusion cell adapted to positron emission tomography (PET), a highly sensitive imaging technology, was developed to measure the passage of gold NPs (AuNPs) in skin samples in continuous mode. US-AuNPs (3.2 nm diam.; TEM) were functionalized with deferoxamine (DFO) and radiolabeled with 89Zr(IV) (half-life: 3.3 days, matching the timeline of diffusion tests). The physicochemical properties of the functionalized US-AuNPs (US-AuNPs-PEG-DFO) were characterized by FTIR (DFO grafting; hydroxamate peaks: 1629.0 cm-1, 1569.0 cm-1), XPS (presence of the O═C-N C 1s peak of DFO at 287.49 eV), and TGA (organic mass fraction). The passage of US-AuNPs-PEG-DFO-89Zr(IV) in skin samples was measured by PET, and the diffusion parameters were extracted thereby. The signals of radioactive US-AuNPs-PEG-DFO-89Zr(IV) leaving the donor compartment, passing through the skin, and entering the acceptor compartment were detected in continuous at concentrations as low as 2.2 nM of Au. The high-sensitivity acquisitions performed in continuous allowed for the first time to extract the lag time to the start of permeation, the lag time to start of the steady state, the diffusion coefficients, and the influx data for AuNPs permeating into the skin. PET could represent a highly valuable tool for the development of nanoparticle-containing topical formulations of drugs and cosmetics.


Assuntos
Nanopartículas Metálicas/química , Tomografia por Emissão de Pósitrons/métodos , Pele/metabolismo , Ouro/química , Permeabilidade , Análise Espectral/métodos
3.
Int J Nanomedicine ; 18: 5831-5869, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37869062

RESUMO

Purpose: Immunomodulatory and broad-spectrum antiviral activities have motivated the evaluation of curcumin for Coronavirus infection 2019 (COVID-19) management. Inadequate bioavailability is the main impediment to the therapeutic effects of oral Cur. This study aimed to develop an optimal curcumin transferosome-loaded thermosensitive in situ gel to improve its delivery to the lungs. Methods: Transferosomes were developed by using 33 screening layouts. The phospholipid concentration as well as the concentration and type of surfactant were considered independent variables. The entrapment efficiency (EE%), size, surface charge, and polydispersity index (PDI) were regarded as dependent factors. A cold technique was employed to develop thermosensitive in-situ gels. Optimized transferosomes were loaded onto the selected gels. The produced gel was assessed based on shape attributes, ex vivo permeability enhancement, and the safety of the nasal mucosa. The in vitro cytotoxicity, antiviral cytopathic effect, and plaque assay (CV/CPE/Plaque activity), and in vivo performance were evaluated after intranasal administration in experimental rabbits. Results: The optimized preparation displayed a particle size of 664.3 ± 69.3 nm, EE% of 82.8 ± 0.02%, ZP of -11.23 ± 2.5 mV, and PDI of 0.6 ± 0.03. The in vitro curcumin release from the optimized transferosomal gel was markedly improved compared with that of the free drug-loaded gel. An ex vivo permeation study revealed a significant improvement (2.58-fold) in drug permeability across nasal tissues of sheep. Histopathological screening confirmed the safety of these preparations. This formulation showed high antiviral activity against SARS-CoV-2 at reduced concentrations. High relative bioavailability (226.45%) was attained after the formula intranasally administered to rabbits compared to the free drug in-situ gel. The curcumin transferosome gel displayed a relatively high lung accumulation after intranasal administration. Conclusion: This study provides a promising formulation for the antiviral treatment of COVID-19 patients, which can be evaluated further in preclinical and clinical studies.


Assuntos
COVID-19 , Curcumina , Humanos , Animais , Coelhos , Ovinos , Lipossomos , Administração Intranasal , Curcumina/farmacologia , SARS-CoV-2 , Portadores de Fármacos , Géis , Antivirais/farmacologia , Tamanho da Partícula
4.
ACS Biomater Sci Eng ; 8(3): 1200-1214, 2022 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-35226460

RESUMO

Cervical cancer is the fourth most common malignancy among women. Compared to other types of cancer, therapeutic agents can be administrated locally at the mucosal vaginal membrane. Thermosensitive gels have been developed over the years for contraception or for the treatment of bacterial, fungal, and sexually transmitted infections. These formulations often carry therapeutic nanoparticles and are now being considered in the arsenal of tools for oncology. They can also be three-dimensionally (3D) printed for a better geometrical adjustment to the anatomy of the patient, thus enhancing the local delivery treatment. In this study, a localized delivery system composed of a Pluronic F127-alginate hydrogel with efficient nanoparticle (NP) release properties was prepared for intravaginal application procedures. The kinetics of hydrogel degradation and its NP releasing properties were demonstrated with ultrasmall gold nanoparticles (∼80% of encapsulated AuNPs released in 48 h). The mucoadhesive properties of the hydrogel formulation were assayed by the periodic acid/Schiff reagent staining, which revealed that 19% of mucins were adsorbed on the gel's surface. The hydrogel formulation was tested for cytocompatibility in three cell lines (HeLa, CRL 2616, and BT-474; no sign of cytotoxicity revealed). The release of AuNPs from the hydrogel and their accumulation in vaginal membranes were quantitatively measured in vitro/ex vivo with positron emission tomography, a highly sensitive modality allowing real-time imaging of nanoparticle diffusion (lag time to start of permeation of 3.3 h, 47% of AuNPs accumulated in the mucosa after 42 h). Finally, the potential of the AuNP-containing Pluronic F127-alginate hydrogel for 3D printing was demonstrated, and the geometrical precision of the 3D printed systems was measured by magnetic resonance imaging (<0.5 mm precision; deviation from the design values <2.5%). In summary, this study demonstrates the potential of Pluronic F127-alginate formulations for the topical administration of NP-releasing gels applied to vaginal wall therapy. This technology could open new possibilities for photothermal and radiosensitizing oncology applications.


Assuntos
Nanopartículas Metálicas , Neoplasias do Colo do Útero , Alginatos , Feminino , Ouro , Humanos , Hidrogéis , Masculino , Nanopartículas Metálicas/uso terapêutico , Poloxâmero , Neoplasias do Colo do Útero/tratamento farmacológico
5.
Int J Nanomedicine ; 16: 683-700, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33536754

RESUMO

PURPOSE: To develop an externally triggered rapid-release targeted system for treating ovarian cancer, gemcitabine (GMC) was entrapped into sonosensitive (SoS) folate (Fo)-modified liposomes (LPs). METHODS: GMC-loaded LPs (GMC LPs), GMC-loaded Fo-targeted LPs (GMC-Fo LPs), and GMC-loaded Fo-targeted SoS LPs (GMC-SoS Fo LPs) were prepared utilizing a film-hydration technique and evaluated based on particle size, ζ-potential, and percentage entrapped drug. Cellular uptake of the fluorescent delivery systems in Fo-expressing ovarian cancer cells was quantified using flow cytometry. Finally, tumor-targeting ability, in vivo evaluation, and pharmacokinetic studies were performed. RESULTS: GMC LPs, GMC-Fo LPs, and GMC-SoS Fo LPs were successfully prepared, with sizes of <120.3±2.4 nm, 39.7 mV ζ-potential, and 86.3%±1.84% entrapped drug. Cellular uptake of GMC-SoS Fo LPs improved 6.51-fold over GMC LPs (under ultrasonic irradiation - p<0.05). However, cellular uptake of GMC-Fo LPs improved just 1.24-fold over GMC LPs (p>0.05). Biodistribution study showed that of GMC concentration in tumors treated with GMC-SoS-Fo LPs (with ultrasound) improved 2.89-fold that of free GMC (p<0.05). In vivo, GMC-SoS Fo LPs showed the highest antiproliferative and antitumor action on ovarian cancer. CONCLUSION: These findings showed that externally triggered rapid-release SoS Fo-modified LPs are a promising system for delivering rapid-release drugs into tumors.


Assuntos
Desoxicitidina/análogos & derivados , Ácido Fólico/química , Ultrassom , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/sangue , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Desoxicitidina/administração & dosagem , Desoxicitidina/sangue , Desoxicitidina/farmacocinética , Desoxicitidina/farmacologia , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Endocitose/efeitos dos fármacos , Feminino , Humanos , Lipossomos , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Tamanho da Partícula , Ratos Sprague-Dawley , Distribuição Tecidual/efeitos dos fármacos , Gencitabina
6.
Pharmaceutics ; 13(4)2021 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-33921796

RESUMO

Nicergoline (NIC) is a semisynthetic ergot alkaloid derivative applied for treatment of dementia and other cerebrovascular disorders. The efficacy of sesame oil to slow and reverse the symptoms of neurodegenerative cognitive disorders has been proven. This work aimed to formulate and optimize sesame oil-based NIC-nanostructured lipid carriers (NIC-NLCs) for intranasal (IN) delivery with expected synergistic and augmented neuroprotective properties. The NIC-NLC were prepared using sesame oil as a liquid lipid. A three-level, three-factor Box-Behnken design was applied to statistically optimize the effect of sesame oil (%) of the total lipid, surfactant concentration, and sonication time on particle size, zeta potential, and entrapment efficacy as responses. Solid-state characterization, release profile, and ex vivo nasal permeation in comparison to NIC solution (NIC-SOL) was studied. In vivo bioavailability from optimized NIC-NLC and NIC-SOL following IN and IV administration was evaluated and compared. The optimized NIC-NLC formula showed an average particle size of 111.18 nm, zeta potential of -15.4 mV, 95.11% entrapment efficacy (%), and 4.6% loading capacity. The NIC-NLC formula showed a biphasic, extended-release profile (72% after 48 h). Permeation of the NIC-NLC formula showed a 2.3 enhancement ratio. Bioavailability studies showed a 1.67 and 4.57 fold increase in plasma and brain following IN administration. The results also indicated efficient direct nose-to-brain targeting properties with the brain-targeting efficiency (BTE%) and direct transport percentage (DTP%) of 187.3% and 56.6%, respectively, after IN administration. Thus, sesame oil-based NIC-NLC can be considered as a promising IN delivery system for direct and efficient brain targeting with improved bioavailability and expected augmented neuroprotective action for the treatment of dementia.

7.
Pharmaceutics ; 12(2)2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-32046289

RESUMO

Based on the recent reports of World Health Organization, increased antibiotic resistance prevalence among bacteria represents the greatest challenge to human health. In addition, the poor solubility, stability, and side effects that lead to inefficiency of the current antibacterial therapy prompted the researchers to explore new innovative strategies to overcome such resilient microbes. Hence, novel antibiotic delivery systems are in high demand. Nanotechnology has attracted considerable interest due to their favored physicochemical properties, drug targeting efficiency, enhanced uptake, and biodistribution. The present review focuses on the recent applications of organic (liposomes, lipid-based nanoparticles, polymeric micelles, and polymeric nanoparticles), and inorganic (silver, silica, magnetic, zinc oxide (ZnO), cobalt, selenium, and cadmium) nanosystems in the domain of antibacterial delivery. We provide a concise description of the characteristics of each system that render it suitable as an antibacterial delivery agent. We also highlight the recent promising innovations used to overcome antibacterial resistance, including the use of lipid polymer nanoparticles, nonlamellar liquid crystalline nanoparticles, anti-microbial oligonucleotides, smart responsive materials, cationic peptides, and natural compounds. We further discuss the applications of antimicrobial photodynamic therapy, combination drug therapy, nano antibiotic strategy, and phage therapy, and their impact on evading antibacterial resistance. Finally, we report on the formulations that made their way towards clinical application.

8.
Virulence ; 11(1): 1142-1157, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32799619

RESUMO

STAPHYLOCOCCUS HAEMOLYTICUS: (S. haemolyticus) is one of the Coagulase-negative staphylococci (CoNS) that inhabits the skin as a commensal. It is increasingly implicated in opportunistic infections, including diabetic foot ulcer (DFU) infections. In contrast to the abundance of information available for S. aureus and S. epidermidis, little is known about the pathogenicity of S. haemolyticus, despite the increased prevalence of this pathogen in hospitalized patients. We described, for the first time, the pathogenesis of different clinical isolates of S. haemolyticus isolated from DFU on primary human skin fibroblast (PHSF) cells. Virulence-related genes were investigated, adhesion and invasion assays were carried out using Giemsa stain, transmission electron microscopy (TEM), MTT and flowcytometry assays. Our results showed that most S. haemolyticus carried different sets of virulence-related genes. S. haemolyticus adhered to the PHSF cells to variable degrees. TEM showed that the bacteria were engulfed in a zipper-like mechanism into a vacuole inside the cell. Bacterial internalization was confirmed using flowcytometry and achieved high intracellular levels. PHSF cells infected with S.haemolyticus suffered from amarked decrease in viability and increased apoptosis when treated with whole bacterial suspensions or cell-free supernatants but not with heat-treated cells. After co-culture with PBMCs, S. haemolyticus induced high levels of pro-inflammatory cytokines. This study highlights the significant development of S. haemolyticus, which was previously considered a contaminant when detected in cultures of clinical samples. Their high ability to adhere, invade and kill the PHSF cells illustrate the severe damage associated with DFU infections. ABBREVIATIONS: CoNS, coagulase-negative staphylococci; DFU, diabetic foot ulcer; DM, diabetes mellitus; DMEM, Dulbecco's Modified Eagle Medium; MTT, 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide; PBMCs,peripheral blood mononuclear cells; PHSF, primary human skin fibroblast; CFU, colony-forming unit.


Assuntos
Fibroblastos/microbiologia , Pele/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus haemolyticus/patogenicidade , Fatores de Virulência/genética , Aderência Bacteriana , Biofilmes/crescimento & desenvolvimento , Biópsia , Células Cultivadas , Citocinas/análise , Humanos , Testes de Sensibilidade Microbiana , Pele/citologia , Staphylococcus haemolyticus/classificação , Virulência/genética
9.
Int J Nanomedicine ; 14: 1551-1562, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30880964

RESUMO

AIM: To develop the topical gel containing transferosomal lidocaine as alternative to painful local anesthetic injection. MATERIALS AND METHODS: The transfersomes were prepared by film hydration technique using soybean phosphatidylcholine and cholesterol. The prepared transfersomes were evaluated for the morphology, drug loading, %EE, particle size and in vitro release. The transferosomal gel of lidocaine was prepared using HPMC k15 as gelling agent and propylene glycol, dimethyl sulfoxide (DMSO), and polyamidoamine dendrimer third generation (PAMAM G3) solutions were used as permeation enhancer. The formulated gels were evaluated for pH, viscosity, drug content and ex-vivo permeation of the gel. The analgesic effect of the formulation was tested using tail flick test. RESULTS: The transfersomes showed that transfersomes (F4) had the highest entrapment efficiency (%EE) approaching 79.87±2.35, low particle size 179.5 nm, and zeta potential of -43.5±4.74 mV. According to the rat tail flick test, the AUC0-90 minutes of the control formulation (lidocaine solution, A) was 352.32±5.87 seconds minutes. While the maximum AUC0-90 minutes value was found to be 570.5±6.81 seconds minutes for gel formulation (F) containing transfersomal lidocaine with PAMAM G3 dendrimer as permeation enhancer. In this case, the local anesthetic efficacy was increased by 1.62-folds as compared to control formulation. CONCLUSION: From the present study, it can be concluded that the topical gel loaded with transfersomal lidocaine shows enhanced skin permeation effect along with increase in local anesthetic action of lidocaine.


Assuntos
Géis/química , Lidocaína/farmacologia , Absorção Cutânea/efeitos dos fármacos , Administração Cutânea , Anestésicos Locais/administração & dosagem , Anestésicos Locais/farmacologia , Animais , Liberação Controlada de Fármacos , Feminino , Concentração de Íons de Hidrogênio , Lipossomos , Masculino , Nanopartículas/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Permeabilidade , Ratos Sprague-Dawley , Reologia , Pele/efeitos dos fármacos , Viscosidade
10.
Drug Des Devel Ther ; 13: 4413-4430, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31920290

RESUMO

BACKGROUND: Sumatriptan succinate (SUT) is a potent drug used for relieving or ending migraine and cluster headaches. SUT bioavailability is low (15%) when it is taken orally owing to its gastric breakdown and bloodstream before reaching the target arteries. AIM: The aim of the study was to enhance SUT bioavailability through developing an intranasal transferosomal mucoadhesive gel. METHODS: SUT-loaded nanotransferosomes were prepared by thin film hydration method and characterized for various parameters such as vesicle diameter, percent entrapment efficiency (%EE), in vitro release and ex vivo permeation studies. The in-situ gels were prepared using various ratios of poloxamer 407, poloxamer 188, and carrageenan and characterized for gelation temperature, mucoadhesive strength, and rheological properties. RESULTS: The prepared transferosomes exhibited percent entrapment efficiencies (%EE) of 40.41±3.02 to 77.47±2.85%, mean diameters of 97.25 to 245.01 nm, sustained drug release over 6 hours, and acceptable ex vivo permeation findings. The optimum formulae were incorporated into poloxamer 407 and poloxamer 188-based thermosensitive in-situ gel using carrageenan as a mucoadhesive polymer. Pharmacokinetic evaluation showed that the prepared in-situ gel of SUT-loaded nano-transferosomes gave enhanced bioavailability, 4.09-fold, as compared to oral drug solution. CONCLUSION: Based on enhancing the bioavailability and sustaining the drug release, it can be concluded that the in-situ gel of SUT-loaded nano-transferosomes were developed as a promising non-invasive drug delivery system for treating migraine.


Assuntos
Desenho de Fármacos , Nanopartículas/química , Sumatriptana/farmacocinética , Administração Intranasal , Animais , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Géis , Lipossomos/química , Lipossomos/metabolismo , Nanopartículas/metabolismo , Tamanho da Partícula , Coelhos , Sumatriptana/administração & dosagem , Sumatriptana/síntese química , Propriedades de Superfície
11.
Int J Nanomedicine ; 14: 2973-2983, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31118616

RESUMO

Objective: Intraocular pressure has always been a great challenge for topical ophthalmic drugs. The study aimed to develop ocular surfactant based nanovesicles (NVs) carried in mucoadhesive nanogel providing efficient topical delivery of acetazolamide (ACZ). Methods: For the sake of optimizing formulation parameters, the effect of the type of edge activator and its ratio to sorbitan monostearate (Span 60) on the mean particle size, entrapment efficiency (%EE), and zeta potential (ZP) of produced NVs was investigated. Results: The selected formulation composed of Span 60:sodium deoxycholate with ratio 80:20 showed an average diameter of 202.90 nm, %EE of 90.2%, and ZP of -38.1 mV with a spherical and smooth surface. The ACZ loaded nanovesicles (ACZ-NVs) were embedded in different concentrations of Chitosan-sodium tripolyphosphate (CS-TPP) nanogels. The nanogel prepared using 1.5% CS showed the most promising viscosity, adhesion time, and rheological behavior (118,246 cP, 290 min, and thixotropic behavior, respectively). The in vitro release of ACZ showed a controlled release profile after incorporation in nanogels. The in vivo irritation test showed minimal irritation for the nanogel formulation compared to ACZ topical suspension. The effect of intraocular pressure lowering was significantly prolonged using ACZ-NV nanogels compared to ACZ oral tablets. Histopathological examination emphasized the healing power of CS on retinal atrophy. Conclusion: The research work indicated a promising potential for successful topical delivery of ACZ.


Assuntos
Acetazolamida/administração & dosagem , Acetazolamida/farmacologia , Sistemas de Liberação de Medicamentos , Olho/efeitos dos fármacos , Nanopartículas/química , Polietilenoglicóis/química , Polietilenoimina/química , Tensoativos/química , Animais , Liberação Controlada de Fármacos , Hexoses/química , Pressão Intraocular/efeitos dos fármacos , Masculino , Nanogéis , Nanopartículas/administração & dosagem , Nanopartículas/ultraestrutura , Coelhos
12.
Oncogene ; 24(13): 2166-74, 2005 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-15735753

RESUMO

Abnormal signalling events mediated by receptor tyrosine kinases (RTKs) contribute to human carcinogenesis. Sprouty2 (Spry2) is a key antagonistic regulator of RTK signalling and suppression of its expression or function may facilitate proliferation and angiogenesis. Using prostate cancer (CaP) as a model, we investigated the significance of Spry2 in human malignancy. We observed downregulated Spry2 expression in invasive CaP cell lines and high-grade clinical CaP (compared to benign prostatic hyperplasia (BPH) and well-differentiated tumours, P=0.041). A large CpG island is associated with hSPRY2, and extensive hypermethylation of this CpG island was observed in 76-82% of high-grade CaP, while control BPH tissues were predominantly unmethylated (P=0.0005). Furthermore, suppressed Spry2 expression correlated with methylation of the CpG region in clinical samples (P=0.004) and treatment with 5-aza-2'-deoxycytidine reactivated Spry2 expression in LNCaP and PC-3M cells. hSPRY2 maps to the long arm of chromosome 13 (13q31.1), where loss of heterozygosity (LOH) has been reported. We found no evidence of mutation; however, we demonstrated 27-40% LOH using flanking markers to hSPRY2. Hence, while biallelic epigenetic inactivation of hSPRY2 represents the main genetic event in prostate carcinogenesis, the observed 27-40% LOH presents evidence of hemizygous deletion with the remaining allele hypermethylated. We therefore propose hSPRY2 as a potential tumour suppressor locus in CaP.


Assuntos
Cromossomos Humanos Par 3 , Genes Supressores de Tumor , Perda de Heterozigosidade , Neoplasias da Próstata/genética , Proteínas/genética , Sequência de Bases , Linhagem Celular Tumoral , Metilação de DNA , Primers do DNA , Regulação Neoplásica da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Proteínas de Membrana , Regiões Promotoras Genéticas/genética
13.
Drug Des Devel Ther ; 10: 277-95, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26834459

RESUMO

Nanoliposomes have an organized architecture that provides versatile functions. In this study, liposomes were used as an ocular carrier for nanogold capped with flucytosine antifungal drug. Gold nanoparticles were used as a contrasting agent that provides tracking of the drug to the posterior segment of the eye for treating fungal intraocular endophthalmitis. The nanoliposomes were prepared with varying molar ratios of lecithin, cholesterol, Span 60, a positive charge inducer (stearylamine), and a negative charge inducer (dicetyl phosphate). Formulation F6 (phosphatidylcholine, cholesterol, Span 60, and stearylamine at a molar ratio of 1:1:1:0.15) demonstrated the highest extent of drug released, which reached 7.043 mg/h. It had a zeta potential value of 42.5±2.12 mV and an average particle size approaching 135.1±12.0 nm. The ocular penetration of the selected nanoliposomes was evaluated in vivo using a computed tomography imaging technique. It was found that F6 had both the highest intraocular penetration depth (10.22±0.11 mm) as measured by the computed tomography and the highest antifungal efficacy when evaluated in vivo using 32 infected rabbits' eyes. The results showed a strong correlation between the average intraocular penetration of the nanoparticles capped with flucytosine and the percentage of the eyes healed. After 4 weeks, all the infected eyes (n=8) were significantly healed (P<0.01) when treated with liposomal formulation F6. Overall, the nanoliposomes encapsulating flucytosine have been proven efficient in treating the infected rabbits' eyes, which proves the efficiency of the nanoliposomes in delivering both the drug and the contrasting agent to the posterior segment of the eye.


Assuntos
Antifúngicos/administração & dosagem , Infecções Oculares Fúngicas/tratamento farmacológico , Flucitosina/administração & dosagem , Nanopartículas Metálicas , Administração Oftálmica , Animais , Antifúngicos/farmacocinética , Química Farmacêutica/métodos , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Excipientes/química , Olho/metabolismo , Olho/microbiologia , Infecções Oculares Fúngicas/microbiologia , Flucitosina/farmacocinética , Ouro/química , Lipossomos , Tamanho da Partícula , Coelhos , Tomografia Computadorizada por Raios X , Resultado do Tratamento
14.
Drug Des Devel Ther ; 9: 3705-27, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26229435

RESUMO

BACKGROUND: The blood-brain barrier prevents many drug moieties from reaching the central nervous system. Therefore, glutathione-modulated nanoliposomes have been engineered to enhance the targeting of flucytosine to the brain. METHODS: Glutathione-modulated nanoliposomes were prepared by thin-film hydration technique and evaluated in the primary brain cells of rats. Lecithin, cholesterol, and span 65 were mixed at 1:1:1 molar ratio. The molar percentage of PEGylated glutathione varied from 0 mol% to 0.75 mol%. The cellular binding and the uptake of the targeted liposomes were both monitored by epifluorescent microscope and flow cytometry techniques. A biodistribution and a pharmacokinetic study of flucytosine and flucytosine-loaded glutathione-modulated liposomes was carried out to evaluate the in vivo brain-targeting efficiency. RESULTS: The size of glutathione-modulated nanoliposomes was <100 nm and the zeta potential was more than -65 mV. The cumulative release reached 70% for certain formulations. The cellular uptake increased as molar percent of glutathione increased to reach the maximum at 0.75 mol%. The uptake of the targeted liposomes by brain cells of the rats was three times greater than that of the nontargeted liposomes. An in vivo study showed that the relative efficiency was 2.632±0.089 and the concentration efficiency was 1.590±0.049, and also, the drug-targeting index was 3.670±0.824. CONCLUSION: Overall, these results revealed that glutathione-PEGylated nanoliposomes enhance the effective delivery of flucytosine to brain and could become a promising new therapeutic option for the treatment of the brain infections.


Assuntos
Encéfalo/metabolismo , Sistemas de Liberação de Medicamentos , Flucitosina/administração & dosagem , Glutationa/química , Animais , Antifúngicos/administração & dosagem , Antifúngicos/farmacocinética , Barreira Hematoencefálica/metabolismo , Excipientes/química , Citometria de Fluxo , Flucitosina/farmacocinética , Lipossomos , Masculino , Nanopartículas , Tamanho da Partícula , Polietilenoglicóis/química , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
15.
J Biomol Screen ; 16(4): 436-42, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21364088

RESUMO

The ribosome-inhibiting toxin ricin binds exposed ß1→4 linked galactosyls on multiple glycolipids and glycoproteins on the cell surface of most eukaryotic cells. After endocytosis, internal cell trafficking is promiscuous, with only a small proportion of ricin proceeding down a productive (cytotoxic) trafficking route to the endoplasmic reticulum (ER). Here, the catalytic ricin A chain traverses the membrane to inactivate the cytosolic ribosomes, which can be monitored by measuring reduction in protein biosynthetic capacity or cell viability. Although some markers have been discovered for the productive pathway, many molecular details are lacking. To identify a more comprehensive set of requirements for ricin intoxication, the authors have developed an RNAi screen in Drosophila S2 cells, screening in parallel the effects of individual RNAi treatments alone and when combined with a ricin challenge. Initial screening of 806 gene knockdowns has revealed a number of candidates for both productive and nonproductive ricin trafficking, including proteins required for transport to the Golgi, plus potential toxin interactors within the ER and cytosol.


Assuntos
Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/genética , Interferência de RNA , Ricina/farmacologia , Animais , Células Cultivadas , Substâncias para a Guerra Química/farmacologia , Drosophila melanogaster/citologia , Resistência a Medicamentos/genética , Biblioteca Gênica , Ensaios de Triagem em Larga Escala
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