RESUMEN
Histone acetylation is a prominent epigenetic modification linked to the memory loss symptoms associated with neurodegenerative disease. The use of existing histone deacetylase inhibitor (HDACi) drugs for treatment is precluded by their weak blood-brain barrier (BBB) permeability and undesirable toxicity. Here, we address these shortcomings by developing a new class of disulfide-based compounds, inspired by the scaffold of the FDA-approved HDACi romidepsin (FK288). Our findings indicate that our novel compound MJM-1 increases the overall level of histone 3 (H3) acetylation in a prostate cancer cell line. In mice, MJM-1 injected intraperitoneally (i.p.) crossed the BBB and could be detected in the hippocampus, a brain region that mediates memory. Consistent with this finding, we found that the post-training i.p. administration of MJM-1 enhanced hippocampus-dependent spatial memory consolidation in male mice. Therefore, MJM-1 represents a potential lead for further optimization as a therapeutic strategy for ameliorating cognitive deficits in aging and neurodegenerative diseases.
Asunto(s)
Encéfalo/metabolismo , Inhibidores de Histona Desacetilasas/síntesis química , Memoria Espacial/efectos de los fármacos , Animales , Línea Celular Tumoral , Inhibidores de Histona Desacetilasas/farmacocinética , Inhibidores de Histona Desacetilasas/farmacología , Ratones , Ratones Endogámicos BALB CRESUMEN
The adaptive immune function of lymph nodes is dependent on constant recirculation of lymphocytes. In this article, we identify neutrophils present in the lymph node at steady state, exhibiting the same capacity for recirculation. In germ-free mice, neutrophils still recirculate through lymph nodes, and in mice cohoused with wild microbiome mice, the level of neutrophils in lymph nodes increases significantly. We found that at steady state, neutrophils enter the lymph node entirely via L-selectin and actively exit via efferent lymphatics via an S1P dependent mechanism. The small population of neutrophils in the lymph node can act as reconnaissance cells to recruit additional neutrophils in the event of bacterial dissemination to the lymph node. Without these reconnaissance cells, there is a delay in neutrophil recruitment to the lymph node and a reduction in swarm formation following Staphylococcus aureus infection. This ability to recruit additional neutrophils by lymph node neutrophils is initiated by LTB4. This study establishes the capacity of neutrophils to recirculate, much like lymphocytes via L-selectin and high endothelial venules in lymph nodes and demonstrates how the presence of neutrophils at steady state fortifies the lymph node in case of an infection disseminating through lymphatics.
Asunto(s)
Ganglios Linfáticos/inmunología , Infiltración Neutrófila/inmunología , Neutrófilos/inmunología , Infecciones Estafilocócicas/inmunología , Animales , Endotelio/inmunología , Endotelio/microbiología , Femenino , Selectina L/inmunología , Ganglios Linfáticos/microbiología , Vasos Linfáticos/inmunología , Vasos Linfáticos/microbiología , Linfocitos/inmunología , Linfocitos/microbiología , Masculino , Ratones , Ratones Endogámicos C57BL , Microbiota/inmunología , Receptores de Esfingosina-1-Fosfato/inmunología , Infecciones Estafilocócicas/microbiología , Vénulas/inmunología , Vénulas/microbiologíaRESUMEN
Pectin-based hydrogel microcarriers have shown promise for drug delivery to the colonic region. Microcarriers must remain stable throughout the upper gastrointestinal tract for effective colonic delivery, an issue that traditional pectin-based microcarriers have faced. The positively-charged natural biopolymer oligochitosan and divalent cation Ca2+ were used to dually cross-link pectin-based hydrogel microcarriers to improve carrier stability through simulated gastric and intestinal environments. Microcarriers were characterized with Scanning Electron Microscope and Fourier-Transform Infrared analysis. An optical microscope was used to observe the change of microcarrier size and morphology over time in the simulated gastrointestinal environments. Fluorescently-labeled Dextran was used as a model drug for this system. Calcium-Oligochitosan-Pectin microcarriers exhibited relatively small drug release in the upper gastrointestinal regions and were responsive to the high pH and enzymatic activity of simulated colonic environment (over 94% release after 2 h), suggesting great potential for colonic drug delivery.
Asunto(s)
Calcio/química , Quitina/análogos & derivados , Colon/efectos de los fármacos , Portadores de Fármacos/química , Pectinas/química , Preparaciones Farmacéuticas/administración & dosificación , Preparaciones Farmacéuticas/química , Química Farmacéutica/métodos , Quitina/química , Quitosano , Sistemas de Liberación de Medicamentos/métodos , Concentración de Iones de Hidrógeno , Oligosacáridos , Solubilidad/efectos de los fármacosRESUMEN
We report a 28-day repeat dose immunotoxicity evaluation of investigational drug MIDD0301, a novel oral asthma drug candidate that targets gamma amino butyric acid type A receptors (GABAA R) in the lung. The study design employed oral administration of mice twice daily throughout the study period with 100 mg/kg MIDD0301 mixed in peanut butter. Compound dosing did not reveal signs of general toxicity as determined by animal weight, organ weight or haematology. Peanut butter plus test drug (in addition to ad libitum standard rodent chow) did not affect weight gain in the adult mice, in contrast to weight loss in 5 mg/kg prednisone-treated mice. Spleen and thymus weights were unchanged in MIDD0301-treated mice, but prednisone significantly reduced the weight of those organs over the 28-day dosing. Similarly, no differences in spleen or thymus histology were observed following MIDD0301 treatment, but prednisone treatment induced morphological changes in the spleen. The number of small intestine Peyer's patches was not affected by MIDD0301 treatment, an important factor for orally administered drugs. Circulating lymphocyte, monocyte and granulocyte numbers were unchanged in the MIDD0301-treated animals, whereas differential lymphocyte numbers were reduced in prednisone-treated animals. MIDD0301 treatment did not alter IgG antibody responses to dinitrophenyl following dinitrophenyl-keyhole limpet haemocyanin immunization, indicating that systemic humoral immune function was not affected. Taken together, these studies show that repeated daily administration of MIDD0301 is safe and not associated with adverse immunotoxicological effects in mice.
Asunto(s)
Antiinflamatorios/administración & dosificación , Asma/tratamiento farmacológico , Azepinas/administración & dosificación , Drogas en Investigación/administración & dosificación , Agonistas de Receptores de GABA-A/administración & dosificación , Compuestos Heterocíclicos con 3 Anillos/administración & dosificación , Imidazoles/administración & dosificación , Tolerancia Inmunológica/efectos de los fármacos , Adyuvantes Inmunológicos/administración & dosificación , Administración Oral , Animales , Antiinflamatorios/efectos adversos , Asma/sangre , Asma/inmunología , Azepinas/farmacología , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Drogas en Investigación/efectos adversos , Femenino , Agonistas de Receptores de GABA-A/efectos adversos , Hemocianinas/administración & dosificación , Hemocianinas/inmunología , Compuestos Heterocíclicos con 3 Anillos/efectos adversos , Humanos , Imidazoles/farmacología , Recuento de Leucocitos , Masculino , Ratones , Prednisona/administración & dosificación , Prednisona/efectos adversos , Pérdida de PesoRESUMEN
We describe lead compound MIDD0301 for the oral treatment of asthma based on previously developed positive allosteric α5ß3γ2 selective GABAA receptor (GABAAR) ligands. MIDD0301 relaxed airway smooth muscle at single micromolar concentrations as demonstrated with ex vivo guinea pig tracheal rings. MIDD0301 also attenuated airway hyperresponsiveness (AHR) in an ovalbumin murine model of asthma by oral administration. Reduced numbers of eosinophils and macrophages were observed in mouse bronchoalveolar lavage fluid without changing mucous metaplasia. Importantly, lung cytokine expression of IL-17A, IL-4, and TNF-α were reduced for MIDD0301-treated mice without changing antiinflammatory cytokine IL-10 levels. Automated patch clamp confirmed amplification of GABA induced current mediated by α1-3,5ß3γ2 GABAARs in the presence of MIDD0301. Pharmacodynamically, transmembrane currents of ex vivo CD4+ T cells from asthmatic mice were potentiated by MIDD0301 in the presence of GABA. The number of CD4+ T cells observed in the lung of MIDD0301-treated mice were reduced by an oral treatment of 20 mg/kg b.i.d. for 5 days. A half-life of almost 14 h was demonstrated by pharmacokinetic studies (PK) with no adverse CNS effects when treated mice were subjected to sensorimotor studies using the rotarod. PK studies also confirmed very low brain distribution. In conclusion, MIDD0301 represents a safe and improved oral asthma drug candidate that relaxes airway smooth muscle and attenuates inflammation in the lung leading to a reduction of AHR at a dosage lower than earlier reported GABAAR ligands.
Asunto(s)
Asma/tratamiento farmacológico , Inflamación/tratamiento farmacológico , Pulmón/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Receptores de GABA-A/metabolismo , Animales , Asma/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Líquido del Lavado Bronquioalveolar/química , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/metabolismo , Constricción , Citocinas/metabolismo , Eosinófilos/efectos de los fármacos , Eosinófilos/metabolismo , Femenino , Cobayas , Inflamación/metabolismo , Ligandos , Pulmón/metabolismo , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Músculo Liso/metabolismo , Ovalbúmina/metabolismo , Hipersensibilidad Respiratoria/metabolismoRESUMEN
We describe pharmacokinetic and pharmacodynamic properties of two novel oral drug candidates for asthma. Phenolic α4ß3γ2 GABAAR selective compound 1 and acidic α5ß3γ2 selective GABAAR positive allosteric modulator compound 2 relaxed airway smooth muscle ex vivo and attenuated airway hyperresponsiveness (AHR) in a murine model of asthma. Importantly, compound 2 relaxed acetylcholine contracted human tracheal airway smooth muscle strips. Oral treatment of compounds 1 and 2 decreased eosinophils in bronchoalveolar lavage fluid in ovalbumin sensitized and challenged mice, thus exhibiting anti-inflammatory properties. Additionally, compound 1 reduced the number of lung CD4+ T lymphocytes and directly modulated their transmembrane currents by acting on GABAARs. Excellent pharmacokinetic properties were observed, including long plasma half-life (up to 15 h), oral availability, and extremely low brain distribution. In conclusion, we report the selective targeting of GABAARs expressed outside the brain and demonstrate reduction of AHR and airway inflammation with two novel orally available GABAAR ligands.
Asunto(s)
Asma/patología , Animales , Líquido del Lavado Bronquioalveolar , Modelos Animales de Enfermedad , Eosinófilos/metabolismo , Citometría de Flujo , Humanos , Pulmón , Masculino , Ratones , Ratones Endogámicos BALB C , Ovalbúmina/metabolismo , Receptores de GABA/metabolismo , Hipersensibilidad Respiratoria/metabolismo , PorcinosRESUMEN
Myeloid-derived suppressor cells (MDSC) contribute to an immunosuppressive network that drives cancer escape by disabling T cell adaptive immunity. The prevailing view is that MDSC-mediated immunosuppression is restricted to tissues where MDSC co-mingle with T cells. Here we show that splenic or, unexpectedly, blood-borne MDSC execute far-reaching immune suppression by reducing expression of the L-selectin lymph node (LN) homing receptor on naïve T and B cells. MDSC-induced L-selectin loss occurs through a contact-dependent, post-transcriptional mechanism that is independent of the major L-selectin sheddase, ADAM17, but results in significant elevation of circulating L-selectin in tumor-bearing mice. Even moderate deficits in L-selectin expression disrupt T cell trafficking to distant LN. Furthermore, T cells preconditioned by MDSC have diminished responses to subsequent antigen exposure, which in conjunction with reduced trafficking, severely restricts antigen-driven expansion in widely-dispersed LN. These results establish novel mechanisms for MDSC-mediated immunosuppression that have unanticipated implications for systemic cancer immunity.
Asunto(s)
Inmunidad Adaptativa , Tolerancia Inmunológica , Selectina L/biosíntesis , Ganglios Linfáticos/inmunología , Linfocitos/inmunología , Células Supresoras de Origen Mieloide/fisiología , Neoplasias/fisiopatología , Animales , Línea Celular Tumoral , Modelos Animales de Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica , Linfocitos/metabolismo , Masculino , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Transgénicos , Neoplasias/inmunología , Interferencia de ARN , Trasplante HeterólogoRESUMEN
A facile strategy has been developed to fabricate nickel oxide hollow microspheres (NiO-HMSs) through a solvothermal method by using a mixed solvent of ethanol and water with the assistance of sodium dodecyl sulfate (SDS). Various techniques, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), and powder X-ray diffraction (XRD), were used to characterize the morphology and the structure of as-prepared samples. It was confirmed that the products possess a hollow microsphere structure that is constructed by interconnecting porous nanoplate framework. Electrochemical studies indicate that the NiO-HMS exhibits excellent stability and high catalytic activity for electrocatalytic oxidation of glucose in alkaline solutions, which enables the NiO-HMS to be used in enzyme-free amperometric sensors for glucose determination. It was demonstrated that the NiO-HMS-based glucose biosensor offers a variety of merits, such as a wide linear response window for glucose concentrations of 1.67 µM-6.87 mM, short response time (3 s), a lower detection limit of 0.53 µM (S/N=3), high sensitivity (~2.39 mA mM(-1) cm(-2)) as well as good stability and repeatability.
Asunto(s)
Técnicas Biosensibles/métodos , Glucemia/análisis , Níquel/química , Técnicas Electroquímicas/métodos , Humanos , Límite de Detección , Microesferas , Oxidación-ReducciónRESUMEN
Inhibitors of vascular endothelial growth factor and its receptors (VEGFRs) are attractive therapeutic candidates for cancer treatment. One such small molecule VEGFR inhibitor, SU5416, limits angiogenesis in vivo and is widely used for investigating VEGFR signaling in tumor pathophysiology. Herein, we describe novel actions of SU5416 on the immune system. Treatment of mice with SU5416 for 3 days induced significant reductions in size and cellularity of peripheral lymph nodes. Interestingly, SU5416 did not affect initial lymphocyte localization to peripheral lymph nodes but did reduce lymphocyte accumulation during long-term migration assays. Treatment with SU5416 also induced severe loss of double-positive thymocytes resulting in thymic atrophy and a reduction in peripheral B cells. Furthermore, immune responses following immunization were reduced in mice treated with SU5416. Findings of thymic atrophy and reduced weight gain during SU5416 treatment suggested elevated corticosterone levels. Indeed, a significant 5-fold increase in serum corticosterone was found 4 hours after treatment with SU5416. Importantly, adrenalectomy negated the effects of SU5416 treatment on primary immune tissues, and partial reversal of SU5416-induced changes was observed following blockade of glucocorticoid receptors. SU5416 has been reported to inhibit the activation of latent transforming growth factor (TGF)-ß, a cytokine involved in the regulation of glucocorticoid release by the adrenal glands. Interestingly, treatment with a TGF-ß receptor inhibitor, showed a similar phenotype as SU5416 treatment, including elevated serum corticosterone levels and thymic atrophy. Therefore, these results suggest that SU5416 induces glucocorticoid release directly from the adrenal glands, possibly by inhibition of TGF-ß activation.
Asunto(s)
Corticosterona/sangre , Indoles/farmacología , Linfocitos/efectos de los fármacos , Pirroles/farmacología , Receptores de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Animales , Inmunidad Activa/efectos de los fármacos , Linfocitos/citología , Ratones , Ratones Endogámicos C57BL , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
A sensitive and selective field-effect transistor (FET) biosensor is demonstrated using vertically-oriented graphene (VG) sheets labeled with gold nanoparticle (NP)-antibody conjugates. VG sheets are directly grown on the sensor electrode using a plasma-enhanced chemical vapor deposition (PECVD) method and function as the sensing channel. The protein detection is accomplished through measuring changes in the electrical signal from the FET sensor upon the antibody-antigen binding. The novel biosensor with unique graphene morphology shows high sensitivity (down to ~2â ng/ml or 13â pM) and selectivity towards specific proteins. The PECVD growth of VG presents a one-step and reliable approach to prepare graphene-based electronic biosensors.
Asunto(s)
Técnicas Biosensibles/instrumentación , Conductometría/instrumentación , Oro/química , Grafito/química , Inmunoensayo/instrumentación , Nanopartículas del Metal/química , Transistores Electrónicos , Diseño de Equipo , Análisis de Falla de EquipoRESUMEN
We report a novel technique to design an insulating membrane with attachment sites on top of single-walled carbon nanotubes (SWNTs) for achieving high sensitivity and selectivity in an SWNT field-effect transistor (FET) biosensor. Because electronic properties of SWNTs are extremely sensitive to the surface state, direct immobilization of proteins or DNAs onto SWNTs will generate surface defects through chemical reactions or physical adsorption, resulting in degradation of performance and instability of SWNT-FET biosensor devices. Here we demonstrate fabrication of novel FET biosensor devices using SWNTs as semiconducting channels, and a monolayer of graphene oxide (GO) membrane covered on the SWNTs as a passivating layer to avoid direct attachment of biomaterials on SWNTs, thereby preserving intrinsic electrical properties of SWNTs. Gold nanoparticles (Au NPs) are decorated on the GO layer for the covalent attachment of biotin, which is then used to selectively detect the target avidin. The passivation with GO layers can effectively lead to enhanced sensitivity of biosensor devices through increasing the on/off ratio of FET sensors.
Asunto(s)
Grafito/química , Nanotubos de Carbono/química , Proteínas/aislamiento & purificación , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Biotina/química , Electrónica , Oro/química , Proteínas/química , Transistores ElectrónicosRESUMEN
A multifunctional gold nanorod (GNR)-based nanoplatform for targeted anticancer drug delivery and positron emission tomography (PET) imaging of tumors was developed and characterized. An anti-cancer drug (i.e., doxorubicin (DOX)) was covalently conjugated onto PEGylated (PEG: polyethylene glycol) GNR nanocarriers via a hydrazone bond to achieve pH-sensitive controlled drug release. Tumor-targeting ligands (i.e., the cyclo(Arg-Gly-Asp-D-Phe-Cys) peptides, cRGD) and (64)Cu-chelators (i.e., 1,4,7-triazacyclononane-N, N', N''-triacetic acid (NOTA)) were conjugated onto the distal ends of the PEG arms to achieve active tumor-targeting and PET imaging, respectively. Based on flow cytometry analysis, cRGD-conjugated nanocarriers (i.e., GNR-DOX-cRGD) exhibited a higher cellular uptake and cytotoxicity than non-targeted ones (i.e., GNR-DOX) in vitro. However, GNR-DOX-cRGD and GNR-DOX nanocarriers had similar in vivo biodistribution according to in vivo PET imaging and biodistribution studies. Due to the unique optical properties of GNRs, this multifunctional GNR-based nanoplatform can potentially be optimized for combined cancer therapies (chemotherapy and photothermal therapy) and multimodality imaging (PET, optical, X-ray computed tomography (CT), etc.).
RESUMEN
L-selectin functions as an important adhesion molecule that mediates tethering and rolling of lymphocytes by binding to high endothelial venule (HEV)-expressed ligands during recirculation. Subsequent lymphocyte arrest and transmigration require activation through binding of HEV-decorated homeostatic chemokines such as secondary lymphoid tissue chemokine (SLC; CCL21) to its counterreceptor, CCR7. Importantly, L-selectin also functions as a signaling molecule. In this study, signaling induced by ligation of L-selectin using mAb or endothelial cell-expressed ligand significantly enhanced the chemotaxis of murine T cells and B cells to SLC but not to other homeostatic chemokines. Consistent with the expression levels of L-selectin in different lymphocyte subsets, L-selectin-mediated enhancement of chemotaxis to SLC was observed for all naive lymphocytes and effector/memory CD8(+) T cells, whereas only a subpopulation of effector/memory CD4(+) T cells responded. During in vivo mesenteric lymph node migration assays, the absence of L-selectin on lymphocytes significantly attenuated both their ability to migrate out of the HEV and their chemotaxis away from the vessel wall. Notably, ligation of L-selectin and/or CCR7 did not result in increased CCR7 expression levels, internalization, or re-expression. Pharmacologic inhibitor studies showed that L-selectin-mediated enhanced chemotaxis to SLC required intact intracellular kinase function. Furthermore, treatment of lymphocytes with the spleen tyrosine kinase family inhibitor piceatannol reduced their ability to migrate across the HEV in peripheral lymph nodes. Therefore, these results suggest that "cross-talk" in the signaling pathways initiated by L-selectin and CCR7 provides a novel mechanism for functional synergy between these two molecules during lymphocyte migration.
Asunto(s)
Quimiocina CCL21/fisiología , Quimiotaxis de Leucocito/fisiología , Selectina L/fisiología , Subgrupos de Linfocitos T/citología , Animales , Anticuerpos Monoclonales/farmacología , Células Cultivadas/citología , Células Cultivadas/efectos de los fármacos , Células Endoteliales/citología , Memoria Inmunológica , Péptidos y Proteínas de Señalización Intracelular/antagonistas & inhibidores , Péptidos y Proteínas de Señalización Intracelular/fisiología , Selectina L/genética , Selectina L/inmunología , Ganglios Linfáticos/citología , Mesenterio/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Proteínas Tirosina Quinasas/fisiología , Receptores CCR7/biosíntesis , Receptores CCR7/genética , Receptores CCR7/fisiología , Receptores CXCR4/biosíntesis , Receptores CXCR4/genética , Transducción de Señal , Organismos Libres de Patógenos Específicos , Estilbenos/farmacología , Quinasa SykRESUMEN
Dickeya dadantii 3937 is a gram-negative phytopathogenic bacterium that expresses genes encoding a type III secretion system (T3SS) in a bistable pattern when cultured in a homogeneous minimal media. In this work, we further characterized the bistable gene expression of T3SS at the single-cell level. We demonstrated that bistable expression of the HrpL-regulon genes, such as hrpA and hrpN, is controlled by the same regulatory mechanism. We also showed that the expression level of the T3SS master regulatory gene hrpL plays an important role in the development of the bistable expression of hrpA. A high expression level of hrpL is required but unable to guarantee the high-state expression of hrpA in a cell. In addition, bistable expression patterns of T3SS genes in other gram-negative pathogens of the Enterobacteriaceae and Pseudomonadaceae families were also described in this study. This suggests that the T3SS bistability might be a conserved population behavior in several gram-negative bacterial pathogens.
Asunto(s)
Proteínas Bacterianas/genética , Sistemas de Secreción Bacterianos/genética , Enterobacteriaceae/genética , Regulación Bacteriana de la Expresión Génica/genética , Genes Reporteros , Bacterias Gramnegativas/genética , Modelos Genéticos , Mutación , Plásmidos , Regiones Promotoras Genéticas/genética , ARN Bacteriano/genética , Factores de Virulencia/genéticaRESUMEN
Multifunctional and water-soluble superparamagnetic iron oxide (SPIO) nanocarriers were developed for targeted drug delivery and positron emission tomography/magnetic resonance imaging (PET/MRI) dual-modality imaging of tumors with integrin α(v)ß3 expression. An anticancer drug was conjugated onto the PEGylated SPIO nanocarriers via pH-sensitive bonds. Tumor-targeting ligands, cyclo(Arg-Gly-Asp-d-Phe-Cys) (c(RGDfC)) peptides, and PET 64Cu chelators, macrocyclic 1,4,7-triazacyclononane-N, N', Nâ³-triacetic acid (NOTA), were conjugated onto the distal ends of the PEG arms. The effectiveness of the SPIO nanocarriers as an MRI contrast agent was evaluated via an in vitro r2 MRI relaxivity measurement. cRGD-conjugated SPIO nanocarriers exhibited a higher level of cellular uptake than cRGD-free ones in vitro. Moreover, cRGD-conjugated SPIO nanocarriers showed a much higher level of tumor accumulation than cRGD-free ones according to non-invasive and quantitative PET imaging, and ex vivo biodistribution studies. Thus, these SPIO nanocarriers demonstrated promising properties for combined targeted anticancer drug delivery and PET/MRI dual-modality imaging of tumors.
Asunto(s)
Dextranos/síntesis química , Diagnóstico por Imagen/métodos , Doxorrubicina/farmacocinética , Portadores de Fármacos/síntesis química , Animales , Medios de Contraste/química , Sistemas de Liberación de Medicamentos , Femenino , Humanos , Concentración de Iones de Hidrógeno , Integrina alfaVbeta3/metabolismo , Imagen por Resonancia Magnética , Nanopartículas de Magnetita , Malonatos/síntesis química , Ratones , Ratones Desnudos , Modelos Animales , Nanomedicina/métodos , Neoplasias/tratamiento farmacológico , Tamaño de la Partícula , Péptidos Cíclicos/química , Tomografía de Emisión de Positrones , Distribución TisularRESUMEN
BACKGROUND: ß7 Integrin, a cell adhesion molecule, is present in the form of α4ß7 integrin or αEß7 integrin. α4ß7 Integrin is expressed on most leucocytes and is essential for their migration to gut-associated lymphoid tissues by interacting with its primary ligand, mucosal addressin cell adhesion molecule-1, which is preferentially expressed in gut-associated lymphoid tissues. Although the importance of α4ß7 integrin in intestinal inflammation has been established, its role in cutaneous inflammation remains to be elucidated. OBJECTIVE: We sought to investigate the role of ß7 integrin in cutaneous inflammation. METHODS: We used a murine contact hypersensitivity model and examined the role of ß7 integrin by using ß7 integrin-deficient and αE integrin-deficient mice. RESULTS: ß7 Integrin-deficient mice, not αE integrin-deficient mice, are defective in contact hypersensitivity responses. ß7 Integrin deficiency does not affect irritant contact dermatitis. The distribution, migration, and function of antigen presenting cells from ß7 integrin-deficient mice are comparable to those from wild-type mice. Moreover, sensitized ß7 integrin-deficient T cells are able to respond to antigen stimuli in vitro and elicit contact hypersensitivity responses when directly injected into the skin. However, they are defective in reaching the skin under inflammatory conditions, resulting in reduced contact hypersensitivity responses when intravenously injected. Furthermore, intraperitoneal injection of anti-α4ß7 integrin neutralizing antibody elicit impaired contact hypersensitivity responses. CONCLUSION: α4ß7 Integrin contributes to contact hypersensitivity responses by regulating T-cell migration to inflammatory skin.
Asunto(s)
Dermatitis por Contacto/inmunología , Integrinas/metabolismo , Piel/inmunología , Linfocitos T/metabolismo , Traslado Adoptivo , Animales , Anticuerpos Bloqueadores/administración & dosificación , Movimiento Celular/efectos de los fármacos , Movimiento Celular/genética , Células Cultivadas , Dermatitis por Contacto/tratamiento farmacológico , Dermatitis por Contacto/genética , Inmunidad Mucosa/efectos de los fármacos , Integrinas/antagonistas & inhibidores , Integrinas/genética , Integrinas/inmunología , Activación de Linfocitos/efectos de los fármacos , Activación de Linfocitos/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Piel/efectos de los fármacos , Piel/patología , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Linfocitos T/patologíaRESUMEN
A multifunctional stable and pH-responsive polymer vesicle nanocarrier system was developed for combined tumor-targeted delivery of an anticancer drug and superparamagnetic iron oxide (SPIO) nanoparticles (NPs). These multifunctional polymer vesicles were formed by heterofunctional amphiphilic triblock copolymers, that is, R (folate (FA) or methoxy)-poly(ethylene glycol)(M(w):5000)-poly(glutamate hydrozone doxorubicin)-poly(ethylene glycol) (M(w):2000)-acrylate (i.e., R (FA or methoxy)-PEG(114)-P(Glu-Hyd-DOX)-PEG(46)-acrylate). The amphiphilic triblock copolymers can self-assemble into stable vesicles in aqueous solution. It was found that the long PEG segments were mostly segregated into the outer hydrophilic PEG layers of the vesicles, thereby providing active tumor targeting via FA, while the short PEG segments were mostly segregated into the inner hydrophilic PEG layer of the vesicles, thereby making it possible to cross-link the inner PEG layer via the acrylate groups for enhanced in vivo stability. The therapeutic drug, DOX, was conjugated onto the polyglutamate segment, which formed the hydrophobic membrane of the vesicles using a pH-sensitive hydrazone bond to achieve pH-responsive drug release, while the hydrophilic SPIO NPs were encapsulated into the aqueous core of the stable vesicles, allowing for ultrasensitive magnetic resonance imaging (MRI) detection. The SPIO/DOX-loaded vesicles demonstrated a much higher r(2) relaxivity value than Feridex, a commercially available SPIO-based T(2) contrast agent, which was attributed to the high SPIO NPs loading level and the SPIO clustering effect in the aqueous core of the vesicles. Results from flow cytometry and confocal laser scanning microscopy (CLSM) analysis showed that FA-conjugated vesicles exhibited higher cellular uptake than FA-free vesicles which also led to higher cytotoxicity. Thus, these tumor-targeting multifunctional SPIO/DOX-loaded vesicles will provide excellent in vivo stability, pH-controlled drug release, as well as enhanced MRI contrast, thereby making targeted cancer therapy and diagnosis possible.
Asunto(s)
Antineoplásicos/metabolismo , Portadores de Fármacos/química , Imagen por Resonancia Magnética/métodos , Polímeros/química , Antineoplásicos/farmacología , Transporte Biológico , Medios de Contraste/química , Doxorrubicina/metabolismo , Doxorrubicina/farmacología , Portadores de Fármacos/síntesis química , Portadores de Fármacos/metabolismo , Portadores de Fármacos/farmacocinética , Compuestos Férricos/química , Transportadores de Ácido Fólico/metabolismo , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Nanopartículas/química , Polímeros/síntesis química , Polímeros/metabolismo , Polímeros/farmacocinética , Sensibilidad y EspecificidadRESUMEN
Multifunctional polymeric vesicles were developed for targeted drug delivery and imaging. To fabricate this system, a biodegradable amphiphilic diblock copolymer, folate-poly(ethylene glycol)-poly(D,L-lactide) was designed and synthesized through sequential anionic polymerization in a well-controlled manner. Hydrophobic superparamagnetic iron oxide nanoparticles were loaded into the hydrophobic membrane for ultra-sensitive magnetic resonance imaging. Meanwhile, the anticancer drug, doxorubicin was encapsulated in the aqueous core of the vesicles. Cell culture experiments demonstrated the potential of polymeric vesicles as an effective targeting nanoplatform for the delivery of anticancer drugs due to the folate attached to the surface of the vesicles.
Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Micelas , Poliésteres/química , Polietilenglicoles/química , Animales , Línea Celular Tumoral , Doxorrubicina/química , Doxorrubicina/farmacocinética , Citometría de Flujo , Ácido Fólico/química , Ratones , Microscopía Confocal , Microscopía Electrónica de TransmisiónRESUMEN
Stable and tumor-targeting multifunctional wormlike polymer vesicles simultaneously loaded with superparamagnetic iron oxide (SPIO) nanoparticles (NPs) as magnetic resonance imaging (MRI) contrast agent and anticancer drug doxorubicin (DOX) were developed for targeted cancer therapy and ultrasensitive MR imaging. These multifunctional wormlike polymer vesicles were formed by heterobifunctional amphiphilic triblock copolymers R (R = methoxy or folate (FA))-PEG(114)-PLA(x)-PEG(46)-acrylate using a double emulsion method. The long PEG segments bearing methoxy/folate groups (CH(3)O/FA-PEG(114)) were mostly segregated to the outer hydrophilic PEG layers of the wormlike vesicles thereby providing active tumor-targeting ability, while the short PEG segments bearing acrylate groups (PEG(46)-acrylate) were mostly segregated onto the inner hydrophilic PEG layers of the wormlike vesicles thereby allowing the inner PEG layers to be crosslinked via free radical polymerization for enhanced in vivo stability. The hydrophobic anticancer drug, DOX, was loaded into the hydrophobic membrane of the wormlike vesicles. Meanwhile, a cluster of hydrophilic SPIO NPs was encapsulated into the aqueous cores of the stable wormlike vesicles with crosslinked inner PEG layers for ultrasensitive MRI detection. Cellular uptake of the FA-conjugated wormlike vesicles facilitated by the folate receptor-mediated endocytosis process was higher than that of the FA-free vesicles thereby leading to high cytotoxicity against the HeLa human cervical tumor cell line. Moreover, the SPIO/DOX-loaded wormlike vesicles with crosslinked inner PEG layers demonstrated a much higher r(2) relaxivity value than Feridex, a commercially available T(2) agent, which can be attributed to the high SPIO NPs loading level as well as the SPIO clustering effect. These unique stable and tumor-targeting multifunctional SPIO/DOX-loaded wormlike polymer vesicles would make targeted cancer theranostics possible thereby paving the road for personalized medicine.