Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 55
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 610(7930): 182-189, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36131013

RESUMO

Most current therapies that target plasma membrane receptors function by antagonizing ligand binding or enzymatic activities. However, typical mammalian proteins comprise multiple domains that execute discrete but coordinated activities. Thus, inhibition of one domain often incompletely suppresses the function of a protein. Indeed, targeted protein degradation technologies, including proteolysis-targeting chimeras1 (PROTACs), have highlighted clinically important advantages of target degradation over inhibition2. However, the generation of heterobifunctional compounds binding to two targets with high affinity is complex, particularly when oral bioavailability is required3. Here we describe the development of proteolysis-targeting antibodies (PROTABs) that tether cell-surface E3 ubiquitin ligases to transmembrane proteins, resulting in target degradation both in vitro and in vivo. Focusing on zinc- and ring finger 3 (ZNRF3), a Wnt-responsive ligase, we show that this approach can enable colorectal cancer-specific degradation. Notably, by examining a matrix of additional cell-surface E3 ubiquitin ligases and transmembrane receptors, we demonstrate that this technology is amendable for 'on-demand' degradation. Furthermore, we offer insights on the ground rules governing target degradation by engineering optimized antibody formats. In summary, this work describes a strategy for the rapid development of potent, bioavailable and tissue-selective degraders of cell-surface proteins.


Assuntos
Anticorpos , Especificidade de Anticorpos , Proteínas de Membrana , Proteólise , Ubiquitina-Proteína Ligases , Animais , Anticorpos/imunologia , Anticorpos/metabolismo , Neoplasias Colorretais/metabolismo , Ligantes , Proteínas de Membrana/imunologia , Proteínas de Membrana/metabolismo , Receptores de Superfície Celular/imunologia , Receptores de Superfície Celular/metabolismo , Especificidade por Substrato , Ubiquitina-Proteína Ligases/imunologia , Ubiquitina-Proteína Ligases/metabolismo
2.
Nature ; 582(7810): 109-114, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32494068

RESUMO

Advances in genetics and sequencing have identified a plethora of disease-associated and disease-causing genetic alterations. To determine causality between genetics and disease, accurate models for molecular dissection are required; however, the rapid expansion of transcriptional populations identified through single-cell analyses presents a major challenge for accurate comparisons between mutant and wild-type cells. Here we generate mouse models of human severe congenital neutropenia (SCN) using patient-derived mutations in the GFI1 transcription factor. To determine the effects of SCN mutations, we generated single-cell references for granulopoietic genomic states with linked epitopes1, aligned mutant cells to their wild-type equivalents and identified differentially expressed genes and epigenetic loci. We find that GFI1-target genes are altered sequentially, as cells go through successive states of differentiation. These insights facilitated the genetic rescue of granulocytic specification but not post-commitment defects in innate immune effector function, and underscore the importance of evaluating the effects of mutations and therapy within each relevant cell state.


Assuntos
Modelos Animais de Doenças , Células Precursoras de Granulócitos/patologia , Mutação , Neutropenia/genética , Neutropenia/patologia , Neutrófilos/patologia , Animais , Candida albicans/imunologia , Candida albicans/patogenicidade , Linhagem da Célula , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Imunidade Inata , Masculino , Camundongos , Camundongos Transgênicos , Neutropenia/congênito , Neutropenia/imunologia , Neutrófilos/imunologia , Fatores de Transcrição/genética
3.
BMC Bioinformatics ; 25(1): 162, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658834

RESUMO

BACKGROUND: The results of high-throughput biology ('omic') experiments provide insight into biological mechanisms but can be challenging to explore, archive and share. The scale of these challenges continues to grow as omic research volume expands and multiple analytical technologies, bioinformatic pipelines, and visualization preferences have emerged. Multiple software applications exist that support omic study exploration and/or archival. However, an opportunity remains for open-source software that can archive and present the results of omic analyses with broad accommodation of study-specific analytical approaches and visualizations with useful exploration features. RESULTS: We present OmicNavigator, an R package for the archival, visualization and interactive exploration of omic studies. OmicNavigator enables bioinformaticians to create web applications that interactively display their custom visualizations and analysis results linked with app-derived analytical tools, graphics, and tables. Studies created with OmicNavigator can be viewed within an interactive R session or hosted on a server for shared access. CONCLUSIONS: OmicNavigator can be found at https://github.com/abbvie-external/OmicNavigator.


Assuntos
Biologia Computacional , Software , Biologia Computacional/métodos , Interface Usuário-Computador , Gráficos por Computador
4.
Int J Toxicol ; 43(2): 184-195, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38108647

RESUMO

Electrocardiographic evaluation is performed in rhesus monkeys to establish the cardiovascular safety of candidate molecules before progressing to clinical trials. These animals are usually immobilized chemically by ketamine (KTM) and tiletamine-zolazepam (TZ) to obtain a steady-state heart rate and to ensure adequate human safety. The present study aimed to evaluate the effect of these anesthetic regimens on different electrocardiographic parameters. Statistically significant lower HR and higher P-wave duration, RR, QRS, and QT intervals were observed in the KTM-anesthetized group in comparison to TZ-anesthetized animals. No significant changes were noticed in the PR interval and p-wave amplitude. Sex-based significance amongst these parameters was observed in male and female animals of TZ- and KTM-anesthetized groups. Regression analysis of four QTc formulas in TZ-anesthetized rhesus monkeys revealed that QTcNAK (Nakayama) better corrected the QT interval than QTcHAS (Hassimoto), QTcBZT (Bazett), and QTcFRD (Fridericia) formulas. QTcNAK exhibited the least correlation with the RR interval (slope closest to zero and r = .01) and displayed no statistical significance between male and female animals. These data will prove useful in the selection of anesthetic regimens for chemical restraint of rhesus monkeys in nonclinical safety evaluation studies.


Assuntos
Anestésicos , Ketamina , Animais , Humanos , Masculino , Feminino , Ketamina/toxicidade , Tiletamina/toxicidade , Macaca mulatta , Zolazepam/toxicidade , Estudos Retrospectivos , Anestésicos/toxicidade , Frequência Cardíaca
5.
Int J Toxicol ; : 10915818241261922, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38901831

RESUMO

These toxicity studies aimed to assess the safety and tolerability of a novel intravenous diclofenac sodium (37.5 mg/mL) formulation containing povidone K12 (80 mg/mL) as the key excipient in Wistar rats. This formulation was tested at doses of 3, 7, and 15 mg/kg/day and was administered daily for 28 days by intravenous route. Toxicokinetic estimation revealed a dose-proportional increase in plasma exposure to diclofenac. The formulation was well tolerated in males; however, mortality was observed in females (2/15) at the highest dose (15 mg/kg/day). Adverse gastrointestinal events related to NSAIDS and a few other treatment-related effects on clinical and anatomic pathology were noted at the 15 mg/kg/day dose, which normalized at the end of the 2-week recovery period. In addition, the excipient povidone K12 was present in a higher amount than the approved Inactive Ingredient Database (IID) limit in the proposed novel formulation. It was qualified through a separate 28-day repeated dose toxicity study by intravenous route in Wistar rats. Povidone K12 was found to be well tolerated and safe up to a dose of 165 mg/kg/day. No treatment-related adverse effects were observed in this study. In conclusion, repeated administration of a novel intravenous formulation containing diclofenac sodium was found to be safe up to the dose of 7 mg/kg/day in female rats and 15 mg/kg/day in male rats.

6.
J Med Virol ; 95(2): e28484, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36625386

RESUMO

The apprehension of needles related to injection site pain, risk of transmitting bloodborne pathogens, and effective mass immunization have led to the development of a needle-free injection system (NFIS). Here, we evaluated the efficacy of the NFIS and needle injection system (NIS) for the delivery and immunogenicity of DNA vaccine candidate ZyCoV-D in rhesus macaques against SARS-CoV-2 infection. Briefly, 20 rhesus macaques were divided into 5 groups (4 animals each), that is, I (1 mg dose by NIS), II (2 mg dose by NIS), III (1 mg dose by NFIS), IV (2 mg dose by NFIS) and V (phosphate-buffer saline [PBS]). The macaques were immunized with the vaccine candidates/PBS intradermally on Days 0, 28, and 56. Subsequently, the animals were challenged with live SARS-CoV-2 after 15 weeks of the first immunization. Blood, nasal swab, throat swab, and bronchoalveolar lavage fluid specimens were collected on 0, 1, 3, 5, and 7 days post infection from each animal to determine immune response and viral clearance. Among all the five groups, 2 mg dose by NFIS elicited significant titers of IgG and neutralizing antibody after immunization with enhancement in their titers postvirus challenge. Besides this, it also induced increased lymphocyte proliferation and cytokine response. The minimal viral load post-SARS-CoV-2 challenge and significant immune response in the immunized animals demonstrated the efficiency of NFIS in delivering 2 mg ZyCoV-D vaccine candidate.


Assuntos
COVID-19 , Vacinas de DNA , Vacinas Virais , Animais , SARS-CoV-2 , Macaca mulatta , Anticorpos Neutralizantes , Anticorpos Antivirais , Imunogenicidade da Vacina
7.
J Pediatr Hematol Oncol ; 45(2): 78-81, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36161878

RESUMO

Burkitt lymphoma (BL) is an aggressive type of non-Hodgkin lymphoma (NHL). With high-dose combination chemotherapy, cure rates are excellent. Treatment for HIV-positive BL is similar to that for HIV-negative BL. Offering long-term intensive chemotherapy is difficult in resource-limited settings. Oral metronomic chemotherapy, though in vogue as a treatment modality, has limited evidence of its efficacy in HIV-positive BL. Here, we present the case of a child who was diagnosed with BL and HIV and administered metronomic chemotherapy, and also review the literature on the role of metronomic chemotherapy in non-Hodgkin lymphoma with and without HIV.


Assuntos
Linfoma de Burkitt , Infecções por HIV , Criança , Humanos , Linfoma de Burkitt/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
8.
Toxicol Mech Methods ; 33(6): 490-501, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36879461

RESUMO

Rhesus monkeys are a non-rodent species employed in the preclinical safety evaluation of pharmaceuticals and biologics. These nonhuman primate species have been increasingly used in biomedical research because of the similarity in their ionic mechanisms of repolarization with humans. Heart rate and QT interval are two primary endpoints in determining the pro-arrhythmic risk of drugs. As heart rate and QT interval have an inverse relationship, any change in heart rate causes a subsequent change in QT interval. This warrants for calculation of a corrected QT interval. This study aimed to identify an appropriate formula that best corrected QT for change in heart rate. We employed seven formulas based on source-species type, clinical relevance, and requirements of various international regulatory guidelines. Data showed that corrected QT interval values varied drastically for different correction formulas. Equations were compared on their slope values based on QTc versus RR plots. The rank order of the slope for different formulas was (closest to farthest from zero) QTcNAK, QTcHAS, QTcBZT, QTcFRD, QTcVDW, QTcHDG, and QTcFRM. QTcNAK emerged to be the best correcting formula in this study. It showed the least correlation with the RR interval (r = -0.01) and displayed no significant difference amongst the sexes. As there is no universally recognized formula for preclinical use, the authors recommend developing a best-case scenario model for specific study designs and individual organizations. The data from this research will be helpful in deciding an appropriate QT correction formula for the safety assessment of new pharmaceuticals and biologics.


Assuntos
Ketamina , Síndrome do QT Longo , Animais , Humanos , Eletrocardiografia , Macaca mulatta , Ketamina/toxicidade , Frequência Cardíaca , Preparações Farmacêuticas , Síndrome do QT Longo/induzido quimicamente
9.
Expert Rev Proteomics ; 19(1): 5-15, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35089822

RESUMO

INTRODUCTION: Mass spectrometry-based single-cell proteomics (scMS) is experiencing rapid evolution due to the increased sensitivity of mass spectrometers as well as advances in multiplexing and sample preparation. To date, researchers have focused on two general approaches to scMS: label-free and isobaric label-based multiplexing. While label-free analysis provides straightforward sample preparation and a clear path to automation, it currently lacks the throughput necessary to practically analyze thousands of single cells. Multiplexed analysis utilizing isobaric labels requires additional sample manipulation but increases throughput such that analyzing thousands of cells is currently achievable. A key feature of multiplexed scMS experiments is a 'carrier proteome' - a sample added at 25x-500x, the single-cell sample that increases the number of proteins that can be identified in an MS analysis. AREAS COVERED: Here, we review early examples of carrier proteomes in quantitative proteomics before summarizing advantages and challenges of using a carrier proteome in scMS experiments. EXPERT OPINION: We conclude that the addition of carrier proteomes improves depth of identification for scMS, but high levels of carrier proteomes can have adverse effects on quantitative accuracy and precision.


Assuntos
Proteoma , Proteômica , Humanos , Espectrometria de Massas , Proteoma/genética
10.
Am J Physiol Lung Cell Mol Physiol ; 320(6): L1025-L1037, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33719549

RESUMO

Pulmonary arterial hypertension (PAH) affects more women than men, although affected females tend to survive longer than affected males. This sex disparity in PAH is postulated to stem from the diverse roles of sex hormones in disease etiology. In animal models, estrogens appear to be implicated not only in pathologic remodeling of pulmonary arteries, but also in protection against right ventricular (RV) hypertrophy. In contrast, the male sex hormone testosterone is associated with reduced survival in male animals, where it is associated with increased RV mass, volume, and fibrosis. However, it also has a vasodilatory effect on pulmonary arteries. Furthermore, patients of both sexes show varying degrees of response to current therapies for PAH. As such, there are many gaps and contradictions regarding PAH development, progression, and therapeutic interventions in male versus female patients. Many of these questions remain unanswered, which may be due in part to lack of effective experimental models that can consistently reproduce PAH pulmonary microenvironments in their sex-specific forms. This review article summarizes the roles of estrogens and related sex hormones, immunological and genetical differences, and the benefits and limitations of existing experimental tools to fill in gaps in our understanding of the sex-based variation in PAH development and progression. Finally, we highlight the potential of a new tissue chip-based model mimicking PAH-afflicted male and female pulmonary arteries to study the sex-based differences in PAH and to develop personalized therapies based on patient sex and responsiveness to existing and new drugs.


Assuntos
Hipertensão Arterial Pulmonar/fisiopatologia , Artéria Pulmonar/fisiopatologia , Caracteres Sexuais , Disfunção Ventricular Direita/fisiopatologia , Animais , Hormônios Esteroides Gonadais/farmacologia , Humanos , Hipertrofia Ventricular Direita/patologia , Hipertrofia Ventricular Direita/fisiopatologia , Hipertensão Arterial Pulmonar/patologia , Artéria Pulmonar/patologia , Disfunção Ventricular Direita/patologia
11.
Biol Blood Marrow Transplant ; 25(9): 1832-1836, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31054984

RESUMO

Cytomegalovirus (CMV) reactivations are common after allogeneic stem cell transplants, and pre-emptive therapy has been found to be effective. However, in India, treatment options are limited because of high cost and toxicity of ganciclovir and unavailability of cidofovir and foscarnet. Leflunomide is a cheap and easily available anti-rheumatoid arthritis drug that has been shown to have anti-CMV properties both in vitro and in vivo. It also has been used effectively for CMV reactivation after renal transplants. In this retrospective analysis, we analyzed 70 allogeneic stem cell transplants that were conducted between April 2015 and February 2017. There were 49 episodes of CMV reactivations in 43 patients in this period. Leflunomide was used in 24 episodes. It was effective in CMV clearance in 9 of the 24 episodes (38%). When the CMV copy number was <2 × 103 copies/mL, leflunomide was effective in 9 of 17 (53%) episodes, but when the copy number was >2 × 103, leflunomide was ineffective in all of the 7 episodes. This difference was statistically significant (P= .022 by Fisher exact test), suggesting that leflunomide may be more effective in clearance of CMV when copy numbers are low.


Assuntos
Infecções por Citomegalovirus/tratamento farmacológico , Citomegalovirus , Leflunomida/administração & dosagem , Transplante de Células-Tronco , Adulto , Aloenxertos , Infecções por Citomegalovirus/sangue , Infecções por Citomegalovirus/etiologia , DNA Viral/sangue , Feminino , Humanos , Masculino , Estudos Retrospectivos
12.
Nanomedicine ; 15(1): 264-273, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30442595

RESUMO

Tissue specific T1/T2 dual contrast abilities for magnetic resonance imaging (MRI) have great significance in initial detection of cancer lesions. Herein, we developed a novel kind of Magnus nano-bullets (Mn-DTPA-F-MSNs) distinguished by magnetic (Fe3O4-NPs) head combined with mesoporous (SiO2) persist body, respectively. Subsequently, modify mesoporous SiO2 group and finally loaded with Mn2+. These Magnus nano-bullets have relaxivity value (r1 = 5.12 mM-1 s-1) and relaxivity value (r2 = 265.32 mM-1 s-1); they were > 2 folds in comparison to control at 3.0 T. Meanwhile, Magnus nano-bullets also offered significant enhancements for the detection of Glutathione (GSH), a biomarker that has been showed a redox responsive T1-weighted MRI effect in vitro and in vivo evaluations with good biocompatibility. Therefore, our finding endorses that Magnus nano-bullets offer a "smart" and tremendous strategy for greater GSH responsive T1/T2 dual MRI image probes for future biomedical applications.


Assuntos
Carcinoma Hepatocelular/diagnóstico , Neoplasias Hepáticas/diagnóstico , Imageamento por Ressonância Magnética/métodos , Compostos de Manganês/química , Nanopartículas/química , Animais , Apoptose , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células , Meios de Contraste/metabolismo , Glutationa/metabolismo , Humanos , Técnicas In Vitro , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Imagens de Fantasmas , Dióxido de Silício/química , Ensaios Antitumorais Modelo de Xenoenxerto
13.
J Microencapsul ; 36(7): 649-658, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31490709

RESUMO

Aim: To reduce the contamination arising from abuse of commercial pesticide formulations, the coaxial electrospray (CES) method was used for one-step microencapsulation and spraying of pesticides. Methods: After optimisation of process parameters, polymeric microcapsules with different structures were fabricated as the carriers of azoxystrobin (AZS). For the resultant microcapsules, the sustained pesticide release was verified in vitro and the adhesion properties were investigated through a normalised rinsing test. Results: The maximum encapsulation efficiency of the fabricated AZS-loaded microcapsules was 99.14%. Compared to commercial AZS aqueous suspension, the microcapsules fabricated by the CES method exhibited improved sustained release performance of AZS, which could be readily controlled by adjusting the shell thicknesses. Moreover, highly enhanced adhesion performance was observed for the AZS-loaded microcapsules directly sprayed in CES process. Conclusions: The CES process is promising to be applied as a one-step microencapsulation and spraying technology for improving pesticide utilisation and reducing environmental pollution.


Assuntos
Preparações de Ação Retardada/química , Praguicidas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Pirimidinas/química , Estrobilurinas/química , Adesividade , Cápsulas/química , Composição de Medicamentos/instrumentação , Desenho de Equipamento , Tamanho da Partícula
14.
Mol Pharm ; 14(12): 4725-4733, 2017 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-29096443

RESUMO

Artemether is one of the most effective drugs for the treatment of chloroquine-resistant and Plasmodium falciparum strains of malaria. However, its therapeutic potency is hindered by its poor bioavailability. To overcome this limitation, we have encapsulated artemether in poly(lactic-co-glycolic) acid (PLGA) core-shell microparticles (MPs) using the coaxial electrospray method. With optimized process parameters including liquid flow rates and applied electric voltages, experiments are systematically carried out to generate a stable cone-jet mode to produce artemether-loaded PLGA-MPs with an average size of 2 µm, an encapsulation efficiency of 78 ± 5.6%, and a loading efficiency of 11.7%. The in vitro release study demonstrates the sustained release of artemether from the core-shell structure in comparison with that of plain artemether and that of MPs produced by single-axial electrospray without any relevant cytotoxicity. The in vivo studies are performed to evaluate the pharmacokinetic characteristics of the artemether-loaded PLGA-MPs. Our study implies that artemether can be effectively encapsulated in a protective shell of PLGA for controlled release kinetics and enhanced oral bioavailability.


Assuntos
Antimaláricos/farmacocinética , Artemisininas/farmacocinética , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Animais , Antimaláricos/administração & dosagem , Antimaláricos/uso terapêutico , Artemeter , Artemisininas/administração & dosagem , Artemisininas/uso terapêutico , Disponibilidade Biológica , Células CACO-2 , Liberação Controlada de Fármacos , Feminino , Humanos , Malária Falciparum/tratamento farmacológico , Masculino , Modelos Animais , Tamanho da Partícula , Poliésteres/química , Ácido Poliglicólico/química , Ratos , Ratos Wistar
15.
Dev Period Med ; 21(2): 95-97, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28796978

RESUMO

Type I intestinal atresias (webs) are rare causes of gastrointestinal obstruction in infants, the most common site being the second portion of the duodenum. According to the Louw and Barnard classification, type 1 atresia has been defined as an intra-luminal web which results in either complete (web with no perforation) or incomplete (web with central perforation) intestinal obstruction. The jejunum is a rare site of such webs. Diagnosis of an incompletely obstructing web due to central perforation is usually difficult and challenging. We present two cases of jejunal web with a central perforation in which the presentation was delayed. Both were managed by excision of the web.


Assuntos
Atresia Intestinal/diagnóstico , Jejuno/anormalidades , Pré-Escolar , Humanos , Lactente , Atresia Intestinal/patologia , Atresia Intestinal/cirurgia , Jejuno/cirurgia , Masculino
16.
Biochemistry ; 55(26): 3607-15, 2016 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-27280697

RESUMO

Apolipophorin III (apoLp-III) is an exchangeable apolipoprotein found in insects and plays an important function in lipid transport. The protein has an unusual five-helix bundle architecture, deviating from the common four-helix bundle motif. To understand the role of the additional helix in apoLp-III, the N-terminal or C-terminal helix was deleted to create a putative four-helix bundle protein. While the protein lacking helix-1 could be expressed in bacteria albeit at reduced yields, apoLp-III lacking helix-5 could not be produced. Mutational analysis by truncating helix-5 showed that a minimum segment of approximately one-third of the C-terminal helix is required for protein expression. The variant lacking helix-5 was produced by inserting a methionine residue between helix-4 and -5; subsequent cyanogenbromide cleavage generated the four-helix variant. Both N- and C-terminal helix deletion variants displayed significantly reduced helical content, protein stability, and tertiary structure. Despite the significantly altered structure, the variants were still fully functional. The rate of dimyristoylphosphatidylcholine vesicle solubilization was enhanced 4-5-fold compared to the wild-type protein, and the deletion variants were effective in binding to lipolyzed low density lipoprotein thereby preventing lipoprotein aggregation. These results show that the additional helix of apoLp-III is not essential for lipid binding but is required for proper folding to keep the protein into a stable conformation.


Assuntos
Apolipoproteínas/química , Apolipoproteínas/metabolismo , Lipoproteínas LDL/metabolismo , Locusta migratoria/metabolismo , Deleção de Sequência/genética , Animais , Apolipoproteínas/genética , Transporte Biológico , Locusta migratoria/genética , Modelos Moleculares , Mutagênese Sítio-Dirigida , Mutação/genética , Ligação Proteica , Conformação Proteica
17.
Pharm Res ; 32(5): 1727-40, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25425053

RESUMO

OBJECTIVES: To investigate the applicability, localization, biodistribution and toxicity of self assembled ionically sodium alginate cross-linked AmB loaded glycol chitosan stearate nanoparticles for effective management of visceral leishmaniasis. METHODS: Here, we fabricated Amphotericin B (AmB) encapsulated sodium alginate-glycol chitosan stearate nanoparticles (AmB-SA-GCS-NP) using strong electrostatic interaction between oppositely charged polymer and copolymer by ionotropic complexation method. The tagged FAmB-SA-GCS-NP was compared with tagged FAmB for in vitro macrophagic uptake in J774A macrophages and in vivo localization in liver, spleen, lung and kidney tissues. The AmB-SA-GCS-NP and plain AmB were compared for in vitro and in vivo antileishmanial activity, pharmacokinetics, organ distribution and toxicity profiling. RESULTS: The morphology of SA-GCS-NP revealed as nanocrystal (size, 196.3 ± 17.2 nm; PDI, 0.216 ± 0.078; zeta potential, (-) 32.4 ± 5.1 mV) by field emission scanning electron microscopy and high resolution transmission electron microscopy. The macrophage uptake and in vivo tissue localization studies shows tagged FAmB-SA-GCS-NP has significantly higher (~1.7) uptake compared to tagged FAmB. The biodistribution study of AmB-SA-GCS-NP showed more localized distribution towards Leishmania infected organs i.e. spleen and liver while lesser towards kidney. The in vitro (IC50, 0.128 ± 0.024 µg AmB/ml) and in vivo (parasite inhibition, 70.21 ± 3.46%) results of AmB-SA-GCS-NP illustrated significantly higher (P < 0.05) efficacy over plain AmB. The monomeric form of AmB within SA-GCS-NP, observed by UV-visible spectroscopy, favored very less in vitro and in vivo toxicities compared to plain AmB. CONCLUSION: The molecular organization, toxicity studies, desired localization and biodistribution of cost effective AmB-SA-GCS-NP was found to be highly effective and can be proved as practical delivery platform for better management of leishmaniasis.


Assuntos
Alginatos/química , Anfotericina B/administração & dosagem , Antiprotozoários/administração & dosagem , Quitosana/química , Portadores de Fármacos/química , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/tratamento farmacológico , Anfotericina B/farmacocinética , Anfotericina B/uso terapêutico , Animais , Antiprotozoários/farmacocinética , Antiprotozoários/uso terapêutico , Linhagem Celular , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Macrófagos/parasitologia , Masculino , Mesocricetus , Nanopartículas/química , Ratos Wistar , Estearatos/química
18.
Bioconjug Chem ; 25(6): 1091-102, 2014 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-24842628

RESUMO

We have designed lectin functionalized Lipo-polymerosome bearing Amphotericin B (Lec-AmB-L-Psome) for specific internalization via lectin receptors overexpressed on infected macrophages of mononuclear phagocytic system (MPS) for the effective management of intramacrophage diseases such as visceral leishmaniasis. The lipo-polymerosome composed of glycol chitosan-stearic acid copolymer (GC-SA25%) and model lipid cholesterol was surface-functionalized with lectin by the EDC/NHS carbodiimide coupling method. Our designed Lec-AmB-L-Psome showed >2-fold enhanced uptake and significantly higher internalization in macrophages as compared to AmB-L-Psome. Importantly, pharmacokinetic and organ distribution studies illustrate significantly higher accumulation of Lec-AmB-L-Psome in MPS especially in liver, spleen, and lung as compared to AmB-L-Psome, Ambisome, and Fungizone. The IC50 value demonstrated that Lec-AmB-L-Psome has 1.63, 2.23, and 3.43 times higher activity than AmB-L-Psome (p < 0.01), Ambisome (p < 0.05), and Fungizone (p < 0.05), respectively. Additionally, the Lec-AmB-L-Psome showed significantly higher splenic parasite inhibition (78.66 ± 3.08%) compared to Fungizone and Ambisome that caused only 56.54 ± 3.91% (p < 0.05) and 66.46 ± 2.08% (p < 0.05) parasite inhibition, respectively, in Leishmania-infected hamsters. The toxicity profile revealed that Lec-AmB-L-Psome is a safe delivery system with diminished nephrotoxicity which is a limiting factor of Fungizone application. Taken together, these studies suggest that this surface functionalized self-assembled Lec-AmB-L-Psome can introduce a new platform to specifically target macrophages for effective management of intramacrophage diseases.


Assuntos
Anfotericina B/farmacologia , Antiprotozoários/farmacologia , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/tratamento farmacológico , Macrófagos/efeitos dos fármacos , Anfotericina B/administração & dosagem , Anfotericina B/química , Animais , Antiprotozoários/administração & dosagem , Antiprotozoários/química , Células Cultivadas , Cricetinae , Lectinas/química , Leishmaniose Visceral/parasitologia , Lipossomos/química , Macrófagos/parasitologia , Masculino , Camundongos , Estrutura Molecular , Testes de Sensibilidade Parasitária , Polímeros/química , Ratos , Ratos Wistar , Distribuição Tecidual
19.
Mol Pharm ; 11(3): 951-63, 2014 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-24495144

RESUMO

Amphotericin B remains the preferred choice for leishmanial infection, but it has limited clinical applications due to substantial dose limiting toxicities. In the present work, AmB has been formulated in lipo-polymerosome (L-Psome) by spontaneous self-assembly of synthesized glycol chitosan-stearic acid copolymer. The optimized L-Psome formulation with vesicle size of 243.5 ± 17.9 nm, PDI of 0.168 ± 0.08 and zeta potential of (+) 27.15 ± 0.46 mV with 25.59 ± 0.87% AmB loading was obtained. The field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) images suggest nearly spherical morphology of L-Psome. An in vitro study showed comparatively sustained AmB release (66.082 ± 1.73% within 24 h) and high plasma stability compared to commercial Ambisome and Fungizone, where glycol chitosan content was found to be efficient in preventing L-Psome destabilization in the presence of plasma protein. In vitro and in vivo toxicity studies revealed less toxicity of AmB-L-Psome compared to commercialized Fungizone and Ambisome favored by monomeric form of AmB within L-Psome, observed by UV-visible spectroscopy. Experimental results of in vitro (macrophage amastigote system) and in vivo (Leishmania donovani infected hamsters) illustrated the efficacy of AmB-L-Psome to augment effective antileishmanial properties supported by upregulation of Th-1 cytokines (TNF-α, IL-12 and IFN-γ) and inducible nitric oxide synthase, and downregulation of Th-2 cytokines (TGF-ß, IL-10 and IL-4), measured by quantitative mRNA analysis by real time PCR (RT-PCR). Conclusively, developed L-Psome system could be a viable alternative to the current less stable, toxic commercial formulations and developed as a highly efficacious drug delivery system.


Assuntos
Anfotericina B/administração & dosagem , Antiprotozoários/administração & dosagem , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Leishmania donovani/efeitos dos fármacos , Leishmaniose/tratamento farmacológico , Nanocápsulas/administração & dosagem , Anfotericina B/química , Anfotericina B/farmacologia , Animais , Antiprotozoários/farmacologia , Western Blotting , Células Cultivadas , Quitina/análogos & derivados , Quitina/química , Cricetinae , Sistemas de Liberação de Medicamentos , Técnicas Imunoenzimáticas , Imunomodulação , Leishmaniose/imunologia , Leishmaniose/parasitologia , Macrófagos/efeitos dos fármacos , Masculino , Mesocricetus , Camundongos , Polímeros/química , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ácidos Esteáricos/química
20.
Mol Pharm ; 11(12): 4314-26, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-25317848

RESUMO

In the present work, a novel nanoemulsion laden with moxifloxacin has been developed for effective management of complicated intra-abdominal infections. Moxifloxacin nanoemulsion fabricated using high pressure homogenization was evaluated for various pharmaceutical parameters, pharmacokinetics (PK) and pharmacodynamics (PD) in rats with E. coli-induced peritonitis and sepsis. The developed nanoemulsion MONe6 (size 168 ± 28 nm and zeta potential (ZP) 24.78 ± 0.45 mV, respectively) was effective for intracellular delivery and sustaining the release of MOX. MONe6 demonstrated improved plasma (AUC(MONe6/MOX) = 2.38-fold) and tissue pharmacokinetics of MOX (AUC(MONe6/MOX) = 2.63 and 1.47 times in lung and liver, respectively). Calculated PK/PD index correlated well with a reduction in bacterial burden in plasma as well as tissues. Enhanced survival on treatment with MONe6 (65.44%) and as compared to the control group (8.22%) was a result of reduction in lipid peroxidation, neutrophil migration, and cytokine levels (TNF-α and IL6) as compared to untreated groups in the rat model of E. coli-induced sepsis. Parenteral nanoemulsions of MOX hold a promising advantage in the therapy of E. coli-induced complicated intra-abdominal infections and is helpful in the prevention of further complications like septic shock and death.


Assuntos
Escherichia coli/patogenicidade , Fluoroquinolonas/uso terapêutico , Infecções Intra-Abdominais/tratamento farmacológico , Infecções Intra-Abdominais/microbiologia , Animais , Fluoroquinolonas/farmacocinética , Interleucina-6/metabolismo , Masculino , Moxifloxacina , Ratos , Sepse/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA