Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Cell Death Dis ; 10(8): 562, 2019 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-31332163

RESUMO

Development of distant metastasis relies on interactions between cancer and stromal cells. CXCL12, also known as stromal-derived factor 1α (SDF-1α), is a major chemokine constitutively secreted in bone marrow, lymph nodes, liver and lung, playing a critical role in the migration and seeding of neoplastic cells. CXCL12 activates the CXCR4 receptor that is overexpressed in several human cancer cells. Recent evidence reveals that tumors induce pre-metastatic niches in target organ producing tumor-derived factors. Pre-metastatic niches represent a tumor growth-favoring microenvironment in absence of cancer cells. A commercially available dermal filler, hyaluronic acid (HA) -based gel, loaded with CXCL12 (CLG) reproduced a "fake" pre-metastatic niche. In vitro, B16-hCXCR4-GFP, human cxcr4 expressing murine melanoma cells efficiently migrated toward CLG. In vivo, CLGs and empty gels (EGs) were subcutaneously injected into C57BL/6 mice and 5 days later B16-hCXCR4-GFP cells were intravenously inoculated. CLGs were able to recruit a significantly higher number of B16-hCXCR4-GFP cells as compared to EGs, with reduced lung metastasis in mice carrying CLG. CLG were infiltrated by higher number of CD45-positive leukocytes, mainly neutrophils CD11b+Ly6G+ cells, myeloid CD11b+Ly6G- and macrophages F4/80. CLG recovered cells recapitulated the features of B16-hCXCR4-GFP (epithelial, melanin rich, MELAN A/ S100/ c-Kit/CXCR4 pos; α-SMA neg). Thus a HA-based dermal filler loaded with CXCL12 can attract and trap CXCR4+tumor cells. The CLG trapped cells can be recovered and biologically characterized. As a corollary, a reduction in CXCR4 dependent lung metastasis was detected.


Assuntos
Quimiocina CXCL12/metabolismo , Preenchedores Dérmicos/metabolismo , Melanoma Experimental/metabolismo , Células Neoplásicas Circulantes/metabolismo , Receptores CXCR4/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Sobrevivência Celular/genética , Quimiocina CXCL12/administração & dosagem , Preenchedores Dérmicos/administração & dosagem , Feminino , Xenoenxertos , Injeções Subcutâneas , Neoplasias Pulmonares/secundário , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Metástase Neoplásica/genética , Receptores CXCR4/genética , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/metabolismo , Transdução de Sinais/genética , Transfecção
2.
Pharmaceutics ; 10(4)2018 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-30304840

RESUMO

This study aimed to develop nanovectors co-encapsulating doxorubicin (Doxo) and zoledronic acid (Zol) for a combined therapy against Doxo-resistant tumors. Chitosan (CHI)-based polyelectrolyte complexes (PECs) prepared by ionotropic gelation technique were proposed. The influence of some experimental parameters was evaluated in order to optimize the PECs in terms of size and polydispersity index (PI). PEC stability was studied by monitoring size and zeta potential over time. In vitro studies were carried out on wild-type and Doxo-resistant cell lines, to assess both the synergism between Doxo and Zol, as well as the restoring of Doxo sensitivity. Polymer concentration, incubation time, and use of a surfactant were found to be crucial to achieving small size and monodisperse PECs. Doxo and Zol, only when encapsulated in PECs, showed a synergistic antiproliferative effect in all the tested cell lines. Importantly, the incubation of Doxo-resistant cell lines with Doxo/Zol co-encapsulating PECs resulted in the restoration of Doxo sensitivity.

3.
Carbohydr Polym ; 191: 112-118, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29661298

RESUMO

Chemoattraction through the CXCR4-CXCL12 axis has been shown to be an important mechanism to direct circulating tumor cells toward distant sites. The objective of this work was to prepare a fake metastatic niche made up of a gel loaded with CXCL12. The gel is designed to create a steep concentration gradient of the chemokine in the proximity of the site of administration/injection, aimed to divert and capture circulating CXCR4+ tumor cells. To this aim, different thermoresponsive gels based on methylcellulose (MC) or poloxamers, loaded with CXCL12, with or without hyaluronic acid (HA) were designed and their mechanical properties correlated with the ability to attract and capture in vitro CXCR4+ cells. Results of in vitro cell studies showed that all prepared gels induced CEM tumor cell migration whereas only gels based on MC embedded with CXCL12 are able to capture them.

4.
Int J Pharm ; 520(1-2): 21-28, 2017 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-28130197

RESUMO

In this work, curcumin (CURC)-encapsulating nanoparticles (NPs), made up of an amphiphilic blend of poloxamers and PLGA (PPC NPs) at different polymer concentrations, were prepared by nanoprecipitation. CURC was preliminarily complexed with (2-hydroxypropyl)-ß-cyclodextrin (HPßCD) to improve its loading efficiency. The formation of host-guest complexes of CURC with HPßCD (CD-CURC) was confirmed by means of 1HNMR studies and differential scanning calorimetry (DSC). Nanoprecipitation allowed to obtain NPs with a small size (90-120nm depending on the polymer concentration), a narrow size distribution and stable in water for 30days at 4°C and in RPMI-1640 cell culture medium up to 72h at 37°C. The in vitro release of CD-CURC, sustained up to 5days, was governed mainly by a diffusive mechanism. It was also found that the produced NPs were efficiently internalized by mesothelioma cells (MSTO-211H) in the cytoplasmic space, at an extent strongly dependent on NP size and polydispesity index, therefore pointing at the importance of NP preparation method in improving their uptake.


Assuntos
Curcumina/química , Curcumina/farmacologia , Portadores de Fármacos/química , Nanopartículas/química , beta-Ciclodextrinas/química , 2-Hidroxipropil-beta-Ciclodextrina , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Precipitação Química , Curcumina/administração & dosagem , Curcumina/farmacocinética , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Humanos , Ácido Láctico/química , Nanopartículas/metabolismo , Tamanho da Partícula , Poloxâmero/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
5.
Carbohydr Polym ; 140: 400-7, 2016 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-26876867

RESUMO

The arrangement of tumor targeting hyaluronic acid (HA) moieties on irinotecan (IRIN)-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) has been directed by means of a gradient of lipophilicity between the oil and water phases of the emulsion used to produce the NPs. PLGA constitutes the NP bulk while HA is superficially exposed, with amphiphilic poloxamers acting as a bridge between PLGA and HA. Differential scanning calorimetry, zeta potential analyses and ELISA tests were employed to support the hypothesis of polymer assembly in NP formulations. The presence of flexible HA chains on NP surface enhances NP size stability over time due to an increased electrostatic repulsion between NPs and a higher degree of hydration of the device surface. IRIN in vitro release kinetics can be sustained up to 7-13 days. In vitro biologic studies indicated that HA-containing NPs were more toxic than bare PLGA NPs against CD44-overexpressing breast carcinoma cells (HS578T), therefore indicating their ability to target CD44 receptor.


Assuntos
Antineoplásicos/química , Camptotecina/análogos & derivados , Portadores de Fármacos/química , Ácido Hialurônico/química , Ácido Láctico/química , Terapia de Alvo Molecular , Nanopartículas/química , Ácido Poliglicólico/química , Antineoplásicos/farmacologia , Camptotecina/química , Camptotecina/farmacologia , Linhagem Celular Tumoral , Liberação Controlada de Fármacos , Humanos , Receptores de Hialuronatos/metabolismo , Irinotecano , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
6.
Eur J Pharm Biopharm ; 93: 37-45, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25794477

RESUMO

The pharmacological potential of curcumin (CURC) is severely restricted because of its low water solubility/absorption, short half-life and poor bioavailability. To overcome these issues, CURC-loaded nanoparticles (NPs) were produced by a double emulsion technique. In particular, NPs were made up of an amphiphilic blend of poloxamers and PLGA to confer stealth properties to the NPs to take advantage of the enhanced permeability and retention (EPR) effect. Different surface properties of NPs made up of bare PLGA and PLGA/poloxamer blend were confirmed by the different interactions of these NPs with serum proteins and also by their ability to be internalized by mesothelioma cell line. The uptake of PLGA/poloxamer NPs induces a persistent block in G0/G1 phase of the cell cycle up to 72 h, thus overcoming the drug tolerance phenomenon, normally evidenced with free CURC.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Curcumina/farmacologia , Portadores de Fármacos , Ácido Láctico/química , Mesotelioma/tratamento farmacológico , Nanopartículas , Poloxâmero/química , Ácido Poliglicólico/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Química Farmacêutica , Curcumina/química , Curcumina/metabolismo , Estabilidade de Medicamentos , Tolerância a Medicamentos , Humanos , Cinética , Mesotelioma/patologia , Nanomedicina , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ligação Proteica , Solubilidade , Propriedades de Superfície , Tecnologia Farmacêutica/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...