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1.
Eur J Public Health ; 30(Suppl_1): i3-i9, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-32391901

RESUMO

BACKGROUND: Forty-three out of 53 of the WHO European Member States have set up political and institutional mechanisms to implement the United Nations (UN) 2030 Agenda for Sustainable Development. This includes governance and institutional mechanisms, engaging stakeholders, identifying targets and indicators, setting governmental and sectoral priorities for action and reporting progress regularly. Still, growing evidence suggests that there is room for advancing implementation of some of the Sustainable Development Goals (SDGs) and targets at a higher pace in the WHO European Region. This article proposes the E4A approach to support WHO European Member States in their efforts to achieve the health-related SDG targets. METHODS: The E4A approach was developed through a 2-year, multi-stage process, starting with the endorsement of the SDG Roadmap by all WHO European Member States in 2017. This approach resulted from a mix of qualitative methods: a semi-structured desk review of existing committal documents and tools; in-country policy dialogs, interviews and reports; joint UN missions and discussion among multi-lateral organizations; consultation with an advisory group of academics and health policy experts across countries. RESULTS: The E-engage-functions as the driver and pace-maker; the 4 As-assess, align, accelerate and account-serve as building blocks composed of policies, processes, activities and interventions operating in continuous and synchronized action. Each of the building blocks is an essential part of the approach that can be applied across geographic and institutional levels. CONCLUSION: While the E4A approach is being finalized, this article aims to generate debate and input to further refine and test this approach from a public health and user perspective.


Assuntos
Nível de Saúde , Desenvolvimento Sustentável , Europa (Continente) , Humanos , Organização Mundial da Saúde
2.
Chemphyschem ; 19(10): 1197-1204, 2018 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-29316144

RESUMO

Electrochemical monitoring of non-electroactive species requires a biosensor that is stable and selective, with sensitivity to physiological concentrations of targeted analytes. We have combined glucose oxidase-modified carbon-fiber microelectrodes with fast-scan cyclic voltammetry for real-time measurements of glucose fluctuations in brain tissue. Work presented herein quantitatively compares three approaches to enzyme immobilization on the microelectrode surface-physical adsorption, hydrogel entrapment, and entrapment in electrospun nanofibers. The data suggest that each of these methods can be used to create functional microbiosensors. Immobilization of glucose oxidase by physical adsorption generates a biosensor with poor sensitivity to glucose and unstable performance. Entrapment of glucose oxidase in poly(vinyl alcohol) nanofibers generates microbiosensors that are effective for glucose measurements over a large linear range, and that may be particularly useful when targeting glucose concentrations in excess of 3 mm, such as in blood. Hydrogel entrapment is the most effective in terms of sensitivity and stability. These microbiosensors can be used for simultaneous monitoring of glucose and dopamine in real time. The findings outlined herein should be applicable to other oxidase enzymes, and thus they are broadly important for the development of new tools for real-time measurements of fluctuating molecules that are not inherently electroactive.


Assuntos
Técnicas Biossensoriais , Carbono/química , Técnicas Eletroquímicas , Glucose Oxidase/metabolismo , Glucose/análise , Animais , Enzimas Imobilizadas , Masculino , Microeletrodos , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
3.
Br Med Bull ; 124(1): 81-90, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29069332

RESUMO

INTRODUCTION: The Sustainable Development Goals (SDGs) are a set of global goals for fair and sustainable health at every level: from planetary biosphere to local community. The aim is to end poverty, protect the planet and ensure that all people enjoy peace and prosperity, now and in the future. SOURCES OF DATA: The UN has established web-sites to inform the implementation of the SDGs and an Inter-Agency and Expert Group on an Indicator Framework. We have searched for independent commentaries and analysis. AREAS OF AGREEMENT: The goals represent a framework that is scientifically robust, and widely intuitive intended to build upon the progress established by the Millennium Development Goals (MDGs). There is a need for system wide strategic planning to integrate the economic, social and environmental dimensions into policy and actions. AREAS OF CONTROVERSY: Many countries have yet to understand the difference between the MDGs and the SDGs, particularly their universality, the huge potential of new data methods to help with their implementation, and the systems thinking that is needed to deliver the vision. The danger is that individual goals may be prioritized without an understanding of the potential positive interactions between goals. GROWING POINTS: There is an increasing understanding that sustainable development needs a paradigm shift in our understanding of the interaction between the real economy and quality of life. There would be many social, environmental and economic benefits in changing our current model. AREAS TIMELY FOR DEVELOPING RESEARCH: We need to develop systems wide understanding of what supports a healthy environment and the art and science of making change.


Assuntos
Conservação dos Recursos Naturais , Saúde Global , Objetivos , Equidade em Saúde , Humanos , Desenvolvimento de Programas , Qualidade de Vida , Responsabilidade Social , Análise de Sistemas , Nações Unidas
4.
Nanomedicine ; 13(5): 1797-1808, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28263813

RESUMO

A ligand decorated, synthetic polypeptide block copolymer platform with environment-responsive capabilities was designed. We evaluated the potential of this system to function as a polymersome for targeted-delivery of a systemic chemotherapy to tumors. Our system employed click chemistry to provide a pH-responsive polypeptide block that drives nanoparticle assembly, and a ligand (folic acid) conjugated PEG block that targets folate-receptor over-expressing cancer cells. These nanocarriers were found to encapsulate a high loading of conventional chemotherapeutics (e.g. doxorubicin at physiological pH) and release the active therapeutic at lysosomal pH upon cellular uptake. The presence of folic acid on the nanoparticle surface facilitated their active accumulation in folate-receptor-overexpressing cancer cells (KB), compared to untargeted carriers. Folate-targeted nanoparticles loaded with doxorubicin also showed enhanced tumor accumulation in folate-receptor positive KB xenografts, resulting in the suppression of tumor growth in an in vivo hind flank xenograft mouse model.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos , Nanopartículas , Peptídeos , Animais , Linhagem Celular Tumoral , Portadores de Fármacos , Ácido Fólico , Humanos , Camundongos , Polímeros
5.
J Am Chem Soc ; 136(16): 5896-9, 2014 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-24724706

RESUMO

The synthesis of polymer therapeutics capable of controlled loading and synchronized release of multiple therapeutic agents remains a formidable challenge in drug delivery and synthetic polymer chemistry. Herein, we report the synthesis of polymer nanoparticles (NPs) that carry precise molar ratios of doxorubicin, camptothecin, and cisplatin. To our knowledge, this work provides the first example of orthogonally triggered release of three drugs from single NPs. The highly convergent synthetic approach opens the door to new NP-based combination therapies for cancer.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Portadores de Fármacos/química , Nanopartículas/química , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica , Camptotecina/administração & dosagem , Camptotecina/química , Camptotecina/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/administração & dosagem , Cisplatino/química , Cisplatino/farmacologia , Preparações de Ação Retardada , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Doxorrubicina/farmacologia , Humanos
6.
Lancet ; 381(9880): 1835-43, 2013 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-23660123

RESUMO

BACKGROUND: The nuclear transcription factor c-Jun is preferentially expressed in basal-cell carcinoma. Dz13 is a deoxyribozyme that targets JUN messenger RNA and has inhibited the growth of a range of tumours in mice. We did a phase 1 study to assess safety and tolerability in human beings. METHODS: Adults with nodular basal-cell carcinoma were recruited from Royal Prince Alfred Hospital, Sydney, Australia, between September, 2010, and October, 2011. Patients were assigned to receive one intratumoral injected dose of 10, 30, or 100 µg Dz13, in a 50 µL volume of lipid carrier, and were assessed for adverse effects in the first 24 h then at 7, 14, and 28 days after injection. Treated tumours were surgically excised 14 days after injection and compared with the baseline biopsy samples for expression of c-Jun and tumorigenesis markers. FINDINGS: Nine patients were recruited, of whom three received each dose of Dz13. All patients completed the study with no drug-related serious adverse events. No systemic Dz13 exposure was detected. c-Jun expression was reduced in the excised tumours of all nine (100%) patients, compared with baseline, and histological tumour depth had decreased in five (56%) of nine. Proportions of cells positive for caspases 3, 8, and 9 and P53 were increased, but those of cells positive for Bcl-2 and MMP-9 were decreased. Infiltration by inflammatory and immune cells was stimulated. INTERPRETATION: Dz13 was safe and well tolerated after single intratumoral injections at all doses. FUNDING: Cancer Institute NSW, Cancer Council Australia, and National Health and Medical Research Council.


Assuntos
Antineoplásicos/administração & dosagem , Carcinoma Basocelular/tratamento farmacológico , DNA Catalítico/administração & dosagem , Neoplasias Cutâneas/tratamento farmacológico , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Carcinoma Basocelular/metabolismo , Carcinoma Basocelular/patologia , DNA Catalítico/efeitos adversos , DNA Catalítico/farmacocinética , Feminino , Humanos , Injeções Intralesionais , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Resultado do Tratamento
7.
Small ; 10(8): 1623-33, 2014 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-24851252

RESUMO

Inorganic nanostructures have been used extensively to package nucleic acids into forms useful for therapeutic applications. Here we report that the two products of transcription, RNA and inorganic pyrophosphate, can self-assemble to form composite microsponge structures composed of nanocrystalline magnesium pyrophosphate sheets (Mg2P2O7•3.5H2O) with RNA adsorbed to their surfaces. The microsponge particles contain high loadings of RNA (15-21 wt.%) that are protected from degradation and can be obtained through a rolling circle mechanism as large concatemers capable of mediating RNAi. The morphology of the RNAi microsponges is influenced by the time-course of the transcription reaction and interactions between RNA and the inorganic phase. Previous work demonstrated that polycations can be used to condense RNAi microsponges into nanoparticles capable of efficient transfection with low toxicity. Our new findings suggest that the formation of these nanoparticles is mediated by the gradual dissolution of magnesium pyrophosphate that occurs in the presence of polycations. The simple one-pot approach for assembling RNAi microsponges along with their unique properties could make them useful for RNA-based therapeutics.


Assuntos
Nanopartículas Metálicas/química , Interferência de RNA , RNA/química , RNA/genética , DNA/química , DNA/genética , Difosfatos/química , Compostos de Magnésio/química , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Varredura , Nanotecnologia , Conformação de Ácido Nucleico , Polietilenoimina/química , RNA/administração & dosagem , Espectrometria por Raios X , Transcrição Gênica
8.
Mol Pharm ; 11(7): 2420-30, 2014 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-24813025

RESUMO

Herein we report the potential of click chemistry-modified polypeptide-based block copolymers for the facile fabrication of pH-sensitive nanoscale drug delivery systems. PEG-polypeptide copolymers with pendant amine chains were synthesized by combining N-carboxyanhydride-based ring-opening polymerization with post-functionalization using azide-alkyne cycloaddition. The synthesized block copolymers contain a polypeptide block with amine-functional side groups and were found to self-assemble into stable polymersomes and disassemble in a pH-responsive manner under a range of biologically relevant conditions. The self-assembly of these block copolymers yields nanometer-scale vesicular structures that are able to encapsulate hydrophilic cytotoxic agents like doxorubicin at physiological pH but that fall apart spontaneously at endosomal pH levels after cellular uptake. When drug-encapsulated copolymer assemblies were delivered systemically, significant levels of tumor accumulation were achieved, with efficacy against the triple-negative breast cancer cell line, MDA-MB-468, and suppression of tumor growth in an in vivo mouse model.


Assuntos
Portadores de Fármacos/química , Endossomos/química , Nanopartículas/química , Peptídeos/química , Polietilenoglicóis/química , Polímeros/química , Animais , Linhagem Celular Tumoral , Doxorrubicina/química , Sistemas de Liberação de Medicamentos/métodos , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Camundongos Endogâmicos BALB C , Polimerização , Solubilidade
9.
Nano Lett ; 11(5): 2096-103, 2011 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-21524115

RESUMO

This paper demonstrates the generation of systemically deliverable layer-by-layer (LbL) nanoparticles for cancer applications. LbL-based nanoparticles designed to navigate the body and deliver therapeutics in a programmable fashion are promising new and alternative systems for drug delivery, but there have been very few demonstrations of their systemic delivery in vivo due to a lack of knowledge in building LbL nanofilms that mimic traditional nanoparticle design to optimize delivery. The key to the successful application of these nanocarriers in vivo requires a systematic analysis of the influence of film architecture and adsorbed polyelectrolyte outer layer on their pharmacokinetics, which has thus far not been examined for this new approach to nanoparticle delivery. Herein, we have taken the first steps in stabilizing and controlling the systemic distribution of multilayer nanoparticles. Our findings highlight the unique character of LbL systems; the electrostatically assembled nanoparticles gain increased stability in vivo with larger numbers of deposited layers, and the final layer adsorbed generates a critical surface cascade, which dictates the surface chemistry and biological properties of the nanoparticle. This outer polyelectrolyte layer dramatically affects not only the degree of nonspecific particle uptake, but also the nanoparticle biodistribution. For hyaluronic acid (HA) outer layers, a long blood elimination half-life (∼9 h) and low accumulation (∼10-15% recovered fluorescence/g) in the liver were observed, illustrating that these systems can be designed to be highly appropriate for clinical translation.


Assuntos
Sistemas de Liberação de Medicamentos , Nanopartículas/química , Nanotecnologia/métodos , Eletricidade Estática , Adsorção , Animais , Humanos , Ácido Hialurônico/química , Fígado/efeitos dos fármacos , Teste de Materiais , Camundongos , Camundongos Endogâmicos BALB C , Preparações Farmacêuticas/administração & dosagem , Propriedades de Superfície , Distribuição Tecidual
10.
Ecol Evol ; 11(9): 3977-3990, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33976788

RESUMO

Bird assemblages in arid Australia are often characterized as being highly variable through time in response to boom and bust dynamics, although the importance of habitat in structuring assemblages at a local-scale is also recognized. We use a novel approach to investigate the importance of rainfall variability in structuring bird assemblages in a resource-limited environment. Monthly bird surveys were conducted at ten plots for 8 years at a botanical and zoological park in central Australia, including five irrigated plots within a fenced area and five natural plots outside. Irrigation-used to promote growth, flowering, and fruiting of plants-created an artificial resource-enhanced environment against which the response of birds to natural fluctuations in season and rainfall were compared. Species richness was generally maintained at a higher level in resource-enhanced plots during dry times but was higher in natural plots when rainfall was high, mainly due to increases in granivores and insectivores. Honeyeaters were consistently more abundant at irrigated plots. Rainfall was important in structuring bird assemblages at all plots; however, assemblages were more stable in irrigated plots and did not respond as dramatically to a period of very high rainfall. The comparative smoothing of fluctuations in the composition and abundance of birds in irrigated areas highlights the importance of primary productivity, normally tied to rainfall, in driving temporal change in arid-zone bird communities. There was also evidence that different plots in differing habitats supported distinct bird assemblages and that this spatial distinctiveness persisted irrespective of rainfall and determined, to some extent, the response to rainfall. Our study is one of few long-term studies of arid bird assemblages and highlights the importance of both long-term cycles of productivity driven by rain and season as well as site differences in the dynamics of arid-zone bird communities. These insights are particularly valuable as climate change further exacerbates rainfall variability worldwide and initiatives to conserve avifauna in increasingly extreme environments may be required.

11.
Lancet Planet Health ; 5(11): e827-e839, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34774123

RESUMO

COVID-19 is disrupting and transforming the world. We argue that transformations catalysed by this pandemic should be used to improve human and planetary health and wellbeing. This paradigm shift requires decision makers and policy makers to go beyond building back better, by nesting the economic domain of sustainable development within social and environmental domains. Drawing on the engage, assess, align, accelerate, and account (E4As) approach to implementing the 2030 Agenda for Sustainable Development, we explore the implications of this kind of radical transformative change, focusing particularly on the role of the health sector. We conclude that a recovery and transition from the COVID-19 pandemic that delivers the future humanity wants and needs requires more than a technical understanding of the transformation at hand. It also requires commitment and courage from leaders and policy makers to challenge dominant constructs and to work towards a truly thriving, equitable, and sustainable future to create a world where economic development is not an end goal itself, but a means to secure the health and wellbeing of people and the planet.


Assuntos
COVID-19 , Saúde Global , Pandemias , COVID-19/epidemiologia , Previsões , Saúde Global/tendências , Humanos , Desenvolvimento Sustentável
12.
Anal Chem ; 82(12): 5205-10, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20503997

RESUMO

Hydrogen peroxide is a reactive oxygen species that is implicated in a number of neurological disease states and that serves a critical role in normal cell function. It is commonly exploited as a reporter molecule enabling the electrochemical detection of nonelectroactive molecules at electrodes modified with substrate-specific oxidative enzymes. We present the first voltammetric characterization of rapid hydrogen peroxide fluctuations at an uncoated carbon fiber microelectrode, demonstrating unprecedented chemical and spatial resolution. The carbon surface was electrochemically conditioned on the anodic scan and the irreversible oxidation of peroxide was detected on the cathodic scan. The oxidation potential was dependent on scan rate, occurring at +1.2 V versus Ag/AgCl at a scan rate of 400 V.s(-1). The relationship between peak oxidation current and concentration was linear across the physiological range tested, with deviation from linearity above 2 mM and a detection limit of 2 muM. Peroxide was distinguished from multiple interferents, both in vitro and in brain slices. The enzymatic degradation of peroxide was monitored, as was peroxide evolution in response to glucose at a glucose oxidase modified carbon fiber electrode. This novel approach provides the requisite sensitivity, selectivity, spatial and temporal resolution to study dynamic peroxide fluctuations in discrete biological locations.


Assuntos
Técnicas Biossensoriais/métodos , Carbono/química , Eletroquímica/métodos , Peróxido de Hidrogênio/análise , Animais , Técnicas Biossensoriais/instrumentação , Química Encefálica , Fibra de Carbono , Eletroquímica/instrumentação , Peróxido de Hidrogênio/metabolismo , Limite de Detecção , Masculino , Microeletrodos , Ratos , Ratos Sprague-Dawley
13.
Int J Pharm ; 591: 119989, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33122113

RESUMO

Small interfering RNA (siRNA) therapy has significant potential for the treatment of myriad diseases, including cancer. While intravenous routes of delivery have been found to be effective for efficient targeting to the liver, achieving high accumulations selectively in other organs, including lung tissues, can be a challenge. We demonstrate the rational design and engineering of a layer-by-layer (LbL) nanoparticle-containing aerosol that is able to achieve efficient, multistage delivery of siRNA in vitro. For the purpose, LbL nanoparticles were, for the first time, encapsulated in composite porous micro scale particles using a supercritical CO2-assisted spray drying (SASD) apparatus using chitosan as an excipient. Such particles exhibited aerodynamic properties highly favorable for pulmonary administration, and effective silencing of mutant KRAS in lung cancer cells derived from tumors of a non-small cell lung cancer (NSCLC) autochthonous model. Furthermore, efficient alveolar accumulation following inhalation in healthy mice was also observed, corroborating in vitro aerodynamic results, and opening new perspectives for further studies of effective lung therapies These results show that multistage aerosols assembled by supercritical CO2-assisted spray drying can enable efficient RNA interference therapy of pulmonary diseases including lung cancer.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Nanopartículas , Administração por Inalação , Aerossóis , Animais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Excipientes , Pulmão , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Camundongos , Interferência de RNA , RNA Interferente Pequeno
14.
Bioeng Transl Med ; 4(2): e10131, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31249881

RESUMO

Advanced staged high-grade serous ovarian cancer (HGSOC) is the leading cause of gynecological cancer death in the developed world, with 5-year survival rates of only 25-30% due to late-stage diagnosis and the shortcomings of platinum-based therapies. A Phase I clinical trial of a combination of free cisplatin and poly(ADP-ribose) polymerase inhibitors (PARPis) showed therapeutic benefit for HGSOC. In this study, we address the challenge of resistance to platinum-based therapy by developing a targeted delivery approach. Novel electrostatic layer-by-layer (LbL) liposomal nanoparticles (NPs) with a terminal hyaluronic acid layer that facilitates CD44 receptor targeting are designed for selective targeting of HGSOC cells; the liposomes can be formulated to contain both cisplatin and the PARPi drug within the liposomal core and bilayer. The therapeutic effectiveness of LbL NP-encapsulated cisplatin and PARPi alone and in combination was compared with the corresponding free drugs in luciferase and CD44-expressing OVCAR8 orthotopic xenografts in female nude mice. The NPs exhibited prolonged blood circulation half-life, mechanistic staged drug release and targeted codelivery of the therapeutic agents to HGSOC cells. Moreover, compared to the free drugs, the NPs resulted in significantly reduced tumor metastasis, extended survival, and moderated systemic toxicity.

15.
Nat Commun ; 9(1): 1991, 2018 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-29777137

RESUMO

Effective treatment for glioblastoma (GBM) is limited by the presence of the blood-brain barrier (BBB) and rapid resistance to single agent therapies. To address these issues, we developed a transferrin-functionalized nanoparticle (Tf-NP) that can deliver dual combination therapies. Using intravital imaging, we show the ability of Tf-NPs to traverse intact BBB in mice as well as achieve direct tumor binding in two intracranial orthotopic models of GBM. Treatment of tumor-bearing mice with Tf-NPs loaded with temozolomide and the bromodomain inhibitor JQ1 leads to increased DNA damage and apoptosis that correlates with a 1.5- to 2-fold decrease in tumor burden and corresponding increase in survival compared to equivalent free-drug dosing. Immunocompetent mice treated with Tf-NP-loaded drugs also show protection from the effects of systemic drug toxicity, demonstrating the preclinical potential of this nanoscale platform to deliver novel combination therapies to gliomas and other central nervous system tumors.


Assuntos
Antineoplásicos Alquilantes/química , Antineoplásicos/administração & dosagem , Azepinas/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Glioma/tratamento farmacológico , Nanopartículas/química , Temozolomida/administração & dosagem , Triazóis/administração & dosagem , Animais , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Azepinas/química , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/fisiopatologia , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos/instrumentação , Glioma/metabolismo , Glioma/fisiopatologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Temozolomida/química , Triazóis/química , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Biomaterials ; 51: 250-256, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25771015

RESUMO

An important aspect in the design of nanomaterials for delivery is an understanding of its uptake and ultimate release to the cytosol of target cells. Real-time chemical sensing using a nanoparticle-based platform affords exquisite insight into the trafficking of materials and their cargo into cells. This versatile and tunable technology provides a powerful tool to probe the mechanism of cellular entry and cytosolic delivery of a variety of materials, allowing for a simple and convenient means to screen materials towards efficient delivery of therapeutics such as nucleic acids.


Assuntos
Endossomos/metabolismo , Sondas Moleculares/química , Nanopartículas/química , Nanotecnologia/métodos , Linhagem Celular Tumoral , Humanos , Concentração de Íons de Hidrogênio , Espaço Intracelular/metabolismo , Nanopartículas/ultraestrutura , Transfecção
17.
Clin Cancer Res ; 21(19): 4410-9, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26034127

RESUMO

PURPOSE: Cross-talk and feedback between the RAS/RAF/MEK/ERK and PI3K/AKT/mTOR cell signaling pathways is critical for tumor initiation, maintenance, and adaptive resistance to targeted therapy in a variety of solid tumors. Combined blockade of these pathways-horizontal blockade-is a promising therapeutic strategy; however, compounded dose-limiting toxicity of free small molecule inhibitor combinations is a significant barrier to its clinical application. EXPERIMENTAL DESIGN: AZD6244 (selumetinib), an allosteric inhibitor of Mek1/2, and PX-866, a covalent inhibitor of PI3K, were co-encapsulated in a tumor-targeting nanoscale drug formulation-layer-by-layer (LbL) nanoparticles. Structure, size, and surface charge of the nanoscale formulations were characterized, in addition to in vitro cell entry, synergistic cell killing, and combined signal blockade. In vivo tumor targeting and therapy was investigated in breast tumor xenograft-bearing NCR nude mice by live animal fluorescence/bioluminescence imaging, Western blotting, serum cytokine analysis, and immunohistochemistry. RESULTS: Combined MAPK and PI3K axis blockade from the nanoscale formulations (160 ± 20 nm, -40 ± 1 mV) was synergistically toxic toward triple-negative breast (MDA-MB-231) and RAS-mutant lung tumor cells (KP7B) in vitro, effects that were further enhanced upon encapsulation. In vivo, systemically administered LbL nanoparticles preferentially targeted subcutaneous MDA-MB-231 tumor xenografts, simultaneously blocked tumor-specific phosphorylation of the terminal kinases Erk and Akt, and elicited significant disease stabilization in the absence of dose-limiting hepatotoxic effects observed from the free drug combination. Mice receiving untargeted, but dual drug-loaded nanoparticles exhibited progressive disease. CONCLUSIONS: Tumor-targeting nanoscale drug formulations could provide a more safe and effective means to synergistically block MAPK and PI3K in the clinic.


Assuntos
Antineoplásicos/administração & dosagem , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Nanopartículas , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/administração & dosagem , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Sinergismo Farmacológico , Feminino , Humanos , Camundongos , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Nanopartículas/química , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Proteínas Quinases/química , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
18.
PLoS One ; 10(5): e0125955, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26017538

RESUMO

BACKGROUND: We report a widespread foodborne outbreak of Cryptosporidium parvum in England and Scotland in May 2012. Cases were more common in female adults, and had no history of foreign travel. Over 300 excess cases were identified during the period of the outbreak. Speciation and microbiological typing revealed the outbreak strain to be C. parvum gp60 subtype IIaA15G2R1. METHODS: Hypothesis generation questionnaires were administered and an unmatched case control study was undertaken to test the hypotheses raised. Cases and controls were interviewed by telephone. Controls were selected using sequential digit dialling. Information was gathered on demographics, foods consumed and retailers where foods were purchased. RESULTS: Seventy-four laboratory confirmed cases and 74 controls were included in analyses. Infection was found to be strongly associated with the consumption of pre-cut mixed salad leaves sold by a single retailer. This is the largest documented outbreak of cryptosporidiosis attributed to a food vehicle.


Assuntos
Criptosporidiose/epidemiologia , Cryptosporidium parvum/patogenicidade , Doenças Transmitidas por Alimentos/epidemiologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Criptosporidiose/parasitologia , Cryptosporidium parvum/genética , Surtos de Doenças , Inglaterra/epidemiologia , Feminino , Humanos , Lactuca/parasitologia , Masculino , Pessoa de Meia-Idade , Folhas de Planta/parasitologia , Escócia/epidemiologia , Adulto Jovem
19.
Biomaterials ; 35(11): 3489-96, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24477190

RESUMO

Translation of micelles from the laboratory to the clinic is limited by a poor understanding of their in vivo fate following administration. In this paper, we establish a robust approach to real-time monitoring of the in vivo stability of micelles using Förster Resonance Energy Transfer (FRET). This characterization method allows for exquisite insight into the fate of micellar constituents, affording the capabilities to rapidly and efficiently evaluate a library of synthetically derived micellar systems as new therapeutic platforms in vivo. FRET-enabled biological characterization further holds potential to tailor material systems being uniquely investigated across the delivery community towards the next generation of stable therapeutics for disease management.


Assuntos
Transferência Ressonante de Energia de Fluorescência/métodos , Micelas , Polímeros/química , Animais , Feminino , Corantes Fluorescentes/metabolismo , Luz , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Espalhamento de Radiação , Distribuição Tecidual
20.
Adv Healthc Mater ; 3(6): 867-75, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24124132

RESUMO

Current treatment options for debilitating bone diseases such as osteosarcoma, osteoporosis, and bone metastatic cancer are suboptimal and have low efficacy. New treatment options for these pathologies require targeted therapy that maximizes exposure to the diseased tissue and minimizes off-target side effects. This work investigates an approach for generating functional and targeted drug carriers specifically for treating primary osteosarcoma, a disease in which recurrence is common and the cure rate has remained around 20%. This approach utilizes the modularity of Layer-by-Layer (LbL) assembly to generate tissue-specific drug carriers for systemic administration. This is accomplished via surface modification of drug-loaded nanoparticles with an aqueous polyelectrolyte, poly(acrylic acid) (PAA), side-chain functionalized with alendronate, a potent clinically used bisphosphonate. Nanoparticles coated with PAA-alendronate are observed to bind and internalize rapidly in human osteosarcoma 143B cells. Encapsulation of doxorubicin, a front-line chemotherapeutic, in an LbL-targeted liposome demonstrates potent toxicity in vitro. Active targeting of 143B xenografts in NCR nude mice with the LbL-targeted doxorubicin liposomes promotes enhanced, prolonged tumor accumulation and significantly improved efficacy. This report represents a tunable approach towards the synthesis of drug carriers, in which LbL enables surface modification of nanoparticles for tissue-specific targeting and treatment.


Assuntos
Portadores de Fármacos/química , Nanopartículas/química , Resinas Acrílicas/química , Alendronato/administração & dosagem , Alendronato/química , Animais , Conservadores da Densidade Óssea/administração & dosagem , Conservadores da Densidade Óssea/química , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Doxorrubicina/administração & dosagem , Doxorrubicina/análogos & derivados , Doxorrubicina/química , Meia-Vida , Humanos , Lipossomos/química , Lipossomos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanopartículas/metabolismo , Osteossarcoma/diagnóstico por imagem , Osteossarcoma/tratamento farmacológico , Osteossarcoma/patologia , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/química , Radiografia , Transplante Heterólogo
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