RESUMEN
Strategies for cancer protein vaccination largely aim to activate the cellular arm of the immune system against cancer cells. This approach, however, is limited since protein vaccines mostly activate the system's humoral arm instead. One way to overcome this problem is to enhance the cross-presentation of such proteins by antigen-presenting cells, which may consequently lead to intense cellular response. Here we examined the ability of listeriolysin O (LLO) incorporated into poly-lactic-co-glycolic acid (PLGA) microspheres to modify the cytosolic delivery of low molecular weight peptides and enhance their cross-presentation. PLGA microspheres were produced in a size suitable for uptake by phagocytic cells. The peptide encapsulation and release kinetics were improved by adding NaCl to the preparation. PLGA microspheres loaded with the antigenic peptide and incorporated with LLO were readily up-taken by phagocytic cells, which exhibited an increase in the expression of peptide-MHC-CI complexes on the cell surface. Furthermore, this system enhanced the activation of a specific T hybridoma cell line, thus simulating cytotoxic T cells. These results establish, for the first time, a proof of concept for the use of PLGA microspheres incorporated with a pore-forming agent and the antigen peptide of choice as a unique cancer protein vaccination delivery platform.
Asunto(s)
Antígenos de Neoplasias/química , Toxinas Bacterianas/química , Citosol/metabolismo , Portadores de Fármacos/química , Proteínas de Choque Térmico/química , Proteínas Hemolisinas/química , Ácido Láctico/química , Microesferas , Ácido Poliglicólico/química , Animales , Células Presentadoras de Antígenos/citología , Células Presentadoras de Antígenos/inmunología , Antígenos de Neoplasias/inmunología , Antígenos de Neoplasias/metabolismo , Transporte Biológico , Supervivencia Celular , Reactividad Cruzada , Liberación de Fármacos , Ratones , Ovalbúmina/inmunología , Péptidos/química , Péptidos/inmunología , Péptidos/metabolismo , Fagocitos/citología , Fagocitos/inmunología , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Células RAW 264.7RESUMEN
Fas ligand (CD95L/APO-1) is considered as a potent anti-tumor agent due to its mediated cell death properties. We have designed a polymeric microencapsulation system, which encapsulates soluble FasL secreting cells. The encapsulated cells continuously release soluble FasL (sFasL) at the tumor site, while the device protects the encapsulated cells from the host immune system. The potential and efficacy of this system are demonstrated in vitro and in vivo for tumor inhibition. Polymeric microcapsules composed of Alginate Poly-l-lysine were optimized to encapsulate L5 secreting sFasL cells. The expression and anti-tumor activities of the sFasL were confirmed in vitro and tumor inhibition was studied in vivo in SCID mice bearing subcutaneous lymphoma tumors. In vitro, sFasL secreted by the encapsulated L5-sFasL cells was biologically active, inhibited proliferation and induced apoptotic cell death in Fas sensitive tumor cells. Mice injected with encapsulated L5-sFasL cells on the day of tumor injection or 10 days after tumor injection showed significant reduction in tumor volume, of 87% and 95%, respectively. Our findings show that encapsulated cells expressing sFasL can be used as a local device and efficiently suppress malignant Fas sensitive tumors with no side effects.
Asunto(s)
Alginatos/uso terapéutico , Apoptosis/efectos de los fármacos , Materiales Biocompatibles/uso terapéutico , Proteína Ligando Fas/metabolismo , Proteína Ligando Fas/uso terapéutico , Linfoma de Células T/inmunología , Linfoma de Células T/prevención & control , Polilisina/análogos & derivados , Animales , Western Blotting , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Proteína Ligando Fas/genética , Técnica del Anticuerpo Fluorescente , Humanos , Técnicas para Inmunoenzimas , Linfoma de Células T/patología , Masculino , Ratones , Ratones Endogámicos DBA , Ratones SCID , Polilisina/uso terapéutico , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Células Tumorales CultivadasRESUMEN
In spite of advances in cell microencapsulation technology in the past three decades, this approach still suffers from obstacles associated with its biocompatibility. We hypothesized that encapsulation system, which incorporates polymeric particles releasing anti-inflammatory drug in addition to the encapsulated cells, will result in improved biocompatibility, thus improving therapeutic efficacy. We have developed, optimized and studied a combined microencapsulation system in which Ibuprofen loaded PLGA microspheres (MS) are co-entrapped with cells. The combined system was developed and optimized in terms of Ibuprofen release profile, and the survival and proliferation of the co-encapsulated cells. The biocompatibility of the system was evaluated in vitro and in vivo. The developed system was shown to release Ibuprofen within two weeks, and support long-term cell viability. The combined system had improved the biocompatibility within the release period of Ibuprofen. All together, the co-encapsulation of anti-inflammatory loaded MS along with cells offers a clear advantage in the development of effective, long lasting cell based drug delivery systems. The choice of the anti-inflammatory agent, or combination of several anti-inflammatory agents needs to be carefully optimized, as well as their release profile to achieve long- term biocompatibility.
Asunto(s)
Alginatos/química , Antiinflamatorios/metabolismo , Portadores de Fármacos/química , Ibuprofeno/metabolismo , Ácido Láctico/química , Microesferas , Ácido Poliglicólico/química , Polilisina/química , Animales , Antiinflamatorios/administración & dosificación , Antiinflamatorios/química , Cápsulas , Línea Celular , Supervivencia Celular/efectos de los fármacos , Cricetinae , Preparaciones de Acción Retardada , Portadores de Fármacos/toxicidad , Estudios de Factibilidad , Ácido Glucurónico/química , Ácidos Hexurónicos/química , Ibuprofeno/administración & dosificación , Ibuprofeno/química , Masculino , Ensayo de Materiales , Ratones , Copolímero de Ácido Poliláctico-Ácido PoliglicólicoRESUMEN
Culturing 3D-expanded human placental-derived adherent stromal cells (ASCs) in the presence of tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) transiently upregulated the secretion of numerous anti-proliferative, anti-angiogenic and pro-inflammatory cytokines. In a 3D-spheroid screening assay, conditioned medium from these induced-ASCs inhibited proliferation of cancer cell lines, including triple-negative breast cancer (TNBC) lines. In vitro co-culture studies of induced-ASCs with MDA-MB-231 human breast carcinoma cells, a model representing TNBC, supports a mechanism involving immunomodulation and angiogenesis inhibition. In vivo studies in nude mice showed that intramuscular administration of induced-ASCs halted MDA-MB-231 cell proliferation, and inhibited tumor progression and vascularization. Thirty percent of treated mice experienced complete tumor remission. Murine serum concentrations of the tumor-supporting cytokines Interleukin-6 (IL-6), Vascular endothelial growth factor (VEGF) and Granulocyte-colony stimulating factor (G-CSF) were lowered to naïve levels. A somatic mutation analysis identified numerous genes which could be screened in patients to increase a positive therapeutic outcome. Taken together, these results show that targeted changes in the secretion profile of ASCs may improve their therapeutic potential.
Asunto(s)
Trasplante de Células/métodos , Medios de Cultivo Condicionados/farmacología , Interferón gamma/farmacología , Placenta/citología , Neoplasias de la Mama Triple Negativas/terapia , Factor de Necrosis Tumoral alfa/farmacología , Animales , Adhesión Celular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Técnicas de Cocultivo , Regulación hacia Abajo , Femenino , Regulación Neoplásica de la Expresión Génica , Factor Estimulante de Colonias de Granulocitos/metabolismo , Humanos , Inyecciones Intramusculares , Interleucina-6/metabolismo , Ratones , Ratones Desnudos , Placenta/efectos de los fármacos , Embarazo , Células del Estroma/citología , Neoplasias de la Mama Triple Negativas/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Nanostructured porous silicon (PSi) thin films, fabricated by the electrochemical anodization of single crystalline Si wafers, are studied as delivery systems for the anticancer drug mitoxantrone dihydrochloride (MTX). The surface chemistry of the PSi carriers was tailored by surface alkylation using thermal hydrosilylation of 1-dodecene and undecylenic acid, followed by physical adsorption or covalent attachment of MTX to the Si scaffold. The nanostructure and the physiochemical properties of the different carriers were characterized by attenuated total reflectance Fourier transform infrared spectroscopy, nitrogen adsorption-desorption and contact angle measurements, demonstrating that surface alkylation results in a pronounced effect on the hydrophobicity/hydrophilicity of the scaffolds and a volumetric gain in pore wall, which in turn results in a decrease in pore diameter (>23%) and available porous volume (>40%). The effect of these key parameters on MTX loading efficacy, release profile, Si scaffold erosion kinetics and in vitro cytotoxicity on human breast carcinoma (MDA-MB-231) cells was studied and compared to the behavior of neat PSi carriers. We show that the chemically modified PSi carriers exhibit sustained release for several days to weeks with minimal to no burst effect, while for the native PSi MTX release was completed within 5h with a substantial burst release of ~40%. Moreover, our in vitro cytotoxicity experiments have clearly demonstrated that the MTX released from all PSi carriers maintained its cytotoxic effect towards MDA-MB-231 cells, in comparison to the low toxicity of the PSi carriers.
Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Mitoxantrona/análogos & derivados , Nanocápsulas/administración & dosificación , Nanocápsulas/química , Silicio/química , Absorción , Antineoplásicos/administración & dosificación , Antineoplásicos/química , Neoplasias de la Mama/patología , Línea Celular Tumoral , Difusión , Humanos , Ensayo de Materiales , Mitoxantrona/administración & dosificación , Mitoxantrona/química , Porosidad , Resultado del TratamientoRESUMEN
Treating brain tumors using inhibitors of angiogenesis is extensively researched and tested in clinical trials. Although anti-angiogenic treatment holds a great potential for treating primary and secondary brain tumors, no clinical treatment is currently approved for brain tumor patients. One of the main hurdles in treating brain tumors is the blood brain barrier - a protective barrier of the brain, which prevents drugs from entering the brain parenchyma. As most therapeutics are excluded from the brain there is an urgent need to develop delivery platforms which will bypass such hurdles and enable the delivery of anti-angiogenic drugs into the tumor bed. Such delivery systems should be able to control release the drug or a combination of drugs at a therapeutic level for the desired time. In this mini-review we will discuss the latest improvements in nano and micro drug delivery platforms that were designed to deliver inhibitors of angiogenesis to the brain.