Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Memory ; 31(8): 1089-1097, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37286332

RESUMEN

We assessed self-defining future projections (SDFPs) in women with breast cancer (BC) and their relationships with disease characteristics and quality of life. Forty women with BC in the course of treatment and 50 controls were asked to generate SDFPs and completed questionnaires for depression and anxiety symptoms and quality of life. There was no group difference regarding specificity, meaning making, probability of produced future events, and the experience of a sense of personal continuity within SDFPs. BC patients' SDFPs were less distant in the future and characterised by more narratives about life threatening events and fewer narratives about future achievements. Chemotherapy was related to narratives about life threatening events and BC. Patients undergoing breast reconstruction reported fewer life-threatening events related to their cancer. Lower quality of life was associated with lower narratives about relationships in patients. Women undergoing treatment for BC envision their future in a less optimistic way with more narratives about life threatening events and a reduced time perspective that varied according to the type of treatment. Self-continuity and ability to imagine future specific events were preserved in patients, which are important processes helping individuals to cope with life difficulties and find meaning and direction in life.


Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/terapia , Calidad de Vida , Ansiedad , Predicción , Narración
2.
Nature ; 523(7558): 92-5, 2015 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-25970250

RESUMEN

The tumour microenvironment may contribute to tumorigenesis owing to mechanical forces such as fibrotic stiffness or mechanical pressure caused by the expansion of hyper-proliferative cells. Here we explore the contribution of the mechanical pressure exerted by tumour growth onto non-tumorous adjacent epithelium. In the early stage of mouse colon tumour development in the Notch(+)Apc(+/1638N) mouse model, we observed mechanistic pressure stress in the non-tumorous epithelial cells caused by hyper-proliferative adjacent crypts overexpressing active Notch, which is associated with increased Ret and ß-catenin signalling. We thus developed a method that allows the delivery of a defined mechanical pressure in vivo, by subcutaneously inserting a magnet close to the mouse colon. The implanted magnet generated a magnetic force on ultra-magnetic liposomes, stabilized in the mesenchymal cells of the connective tissue surrounding colonic crypts after intravenous injection. The magnetically induced pressure quantitatively mimicked the endogenous early tumour growth stress in the order of 1,200 Pa, without affecting tissue stiffness, as monitored by ultrasound strain imaging and shear wave elastography. The exertion of pressure mimicking that of tumour growth led to rapid Ret activation and downstream phosphorylation of ß-catenin on Tyr654, imparing its interaction with the E-cadherin in adherens junctions, and which was followed by ß-catenin nuclear translocation after 15 days. As a consequence, increased expression of ß-catenin-target genes was observed at 1 month, together with crypt enlargement accompanying the formation of early tumorous aberrant crypt foci. Mechanical activation of the tumorigenic ß-catenin pathway suggests unexplored modes of tumour propagation based on mechanical signalling pathways in healthy epithelial cells surrounding the tumour, which may contribute to tumour heterogeneity.


Asunto(s)
Carcinogénesis/patología , Neoplasias del Colon/fisiopatología , Presión , Microambiente Tumoral , beta Catenina/genética , Transporte Activo de Núcleo Celular , Animales , Células Epiteliales/citología , Células Epiteliales/patología , Femenino , Regulación Neoplásica de la Expresión Génica , Imanes , Masculino , Nanopartículas del Metal , Ratones , Ratones Endogámicos C57BL , Fosforilación , Proteínas Proto-Oncogénicas c-ret/metabolismo , Receptores Notch/genética , Receptores Notch/metabolismo , Transducción de Señal , beta Catenina/metabolismo
3.
Molecules ; 26(13)2021 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-34210027

RESUMEN

The inhibition of the protein function for therapeutic applications remains challenging despite progress these past years. While the targeting application of molecularly imprinted polymer are in their infancy, no use was ever made of their magnetic hyperthermia properties to damage proteins when they are coupled to magnetic nanoparticles. Therefore, we have developed a facile and effective method to synthesize magnetic molecularly imprinted polymer nanoparticles using the green fluorescent protein (GFP) as the template, a bulk imprinting of proteins combined with a grafting approach onto maghemite nanoparticles. The hybrid material exhibits very high adsorption capacities and very strong affinity constants towards GFP. We show that the heat generated locally upon alternative magnetic field is responsible of the decrease of fluorescence intensity.


Asunto(s)
Proteínas Fluorescentes Verdes/química , Nanopartículas Magnéticas de Óxido de Hierro/química , Polímeros Impresos Molecularmente/química , Desnaturalización Proteica
4.
Psychooncology ; 28(8): 1679-1686, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31152683

RESUMEN

OBJECTIVE: Intrafamilial disclosure of hereditary cancer predisposition in BRCA1/2 and mismatch repair gene (MMR) syndromes allows appropriate prevention strategies in at-risk relatives. We previously showed in a nationwide study that the uptake of genetic targeted testing (GTT) in these families was only 30%. We aimed to identify the clinical and psychosocial factors affecting the probands' intrafamilial disclosure and relatives' uptake of GTT in BRCA1/2 or MMR syndromes. METHODS: We assessed clinical variables, family history, and psychosocial variables of probands (depressive symptoms, anxiety, alexithymia, optimism, coping, family relationship, perception of cancer risks, and of hereditary transmission), together with disclosure and uptake of GTT within 103 French BRCA1/2 or MMR families. RESULTS: Among relatives eligible for GTT, 68% were informed of the predisposition, and 37% underwent GTT, according to probands' reports. Intrafamilial disclosure was inversely associated with the degree of kinship (P < .01). In multivariable analysis, disclosure increased with time since probands' genetic diagnosis (P < .01) and probands' feeling of family cohesion (0.01). GTT uptake increased with probands' depressive symptoms (0.02) and decreased with probands' perception of cancer risks (0.03). BRCA1/2 and MMR groups did not differ concerning family information and GTT uptake. CONCLUSIONS: This study identified factors affecting disclosure to relatives and GTT uptake in BRCA1/2 and MMR syndromes and gives new insights to improve probands' follow-up and intrafamilial sharing of genetic information.


Asunto(s)
Proteína BRCA1 , Proteína BRCA2 , Reparación de la Incompatibilidad de ADN/genética , Revelación , Familia , Predisposición Genética a la Enfermedad , Pruebas Genéticas , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación
5.
Scand J Caring Sci ; 33(2): 467-477, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30664270

RESUMEN

PURPOSE: To our knowledge, only one study has assessed Quality of Life (QOL) as a predictor of return to work (RTW) during breast cancer treatment and one has evaluated multidimensional cancer-related fatigue (CRF) as a determinant of RTW. However, no study has assessed the impact of changes in these variables on RTW. The objective of this study was to evaluate QOL, multidimensional CRF and changes in these variables as determinants of RTW during breast cancer treatment. METHODS: We performed a longitudinal study of 68 patients with a mean age of 46.97 years (SD = 6.92), who were employed at the time of diagnosis. Women were assessed at the beginning of adjuvant treatments (T0) and followed up with by telephone at three (T1) and 6 months later (T2), using questionnaires (QLQ-C30; MFI-20). RESULTS: Global QOL, OR = 1.12 [1.01-1.25], sleep disturbance, OR = 1.04 [1.002-1.08], fatigue (QLQ-C30), OR = 0.93 [0.88-0.99], nausea-vomiting, OR = 0.84 [0.73-0.97], reduced motivation, OR = 1.49 [1.05-2.11] and general fatigue, OR = 0.79 [0.63-0.99] at T0 were associated with RTW at T1. At T2 global QOL, OR = 1.09 [1.01-1.17], cognitive functioning, OR = 1.10 [1.03-1.17], general fatigue, OR = 1.82 [1.04-3.17] and mental fatigue, OR = 0.29 [0.11-0.81] were associated with RTW. Furthermore, changes in mental fatigue were associated with RTW at T2, OR = 0.02 [0.001-0.29]. CONCLUSIONS: Quality of life, fatigue and their changes in them, especially cognitive functioning and mental fatigue, can play an important role in predicting the RTW of women with breast cancer. This confirms the importance of multidisciplinary care for cancer and the emergence of a theoretical psychological model of RTW.


Asunto(s)
Neoplasias de la Mama/psicología , Fatiga/psicología , Predicción/métodos , Calidad de Vida/psicología , Reinserción al Trabajo/psicología , Adulto , Femenino , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Encuestas y Cuestionarios
6.
Molecules ; 24(5)2019 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-30857260

RESUMEN

A polyol method was used to obtain ultrasmall ZnO nanoparticles (NPs) doped with iron ions and coated with a low molecular weight fucoidan in order to perform in vivo MR and ex vivo fluorescence imaging of athrothrombosis. During the synthesis, the early elimination of water by azeotropic distillation with toluene allowed us to produce NPs which size, determined by XRD and TEM, decreased from 7 nm to 4 nm with the increase of iron/zinc ratios from 0.05 to 0.50 respectively. For the highest iron content (NP-0.50) NPs were evidenced as a mixture of nanocrystals made of wurtzite and cubic phase with a molar ratio of 2.57:1, although it was not possible to distinguish one from the other by TEM. NP-0.50 were superparamagnetic and exhibited a large emission spectrum at 470 nm when excited at 370 nm. After surface functionalization of NP-0.50 with fucoidan (fuco-0.50), the hydrodynamic size in the physiological medium was 162.0 ± 0.4 nm, with a corresponding negative zeta potential of -48.7 ± 0.4 mV, respectively. The coating was evidenced by FT-IR spectra and thermogravimetric analysis. Aqueous suspensions of fuco-0.50 revealed high transverse proton relaxivities (T2) with an r2 value of 173.5 mM-1 s-1 (300 K, 7.0 T) and remained stable for more than 3 months in water or in phosphate buffer saline without evolution of the hydrodynamic size and size distribution. No cytotoxic effect was observed on human endothelial cells up to 48 h with these NPs at a dose of 0.1 mg/mL. After injection into a rat model of atherothrombosis, MR imaging allowed the localization of diseased areas and the subsequent fluorescence imaging of thrombus on tissue slices.


Asunto(s)
Medios de Contraste/química , Compuestos Férricos/química , Nanopartículas/química , Óxido de Zinc/química , Imagen por Resonancia Magnética , Polisacáridos/química
7.
Ann Surg Oncol ; 23(7): 2350-6, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26957504

RESUMEN

BACKGROUND: Skin-sparing mastectomy (SSM) with immediate breast reconstruction (IBR) is increasingly used in invasive breast cancer. However, adjuvant chemotherapy (CT) and radiotherapy (RT) can increase the rate of local complications. OBJECTIVE: The aim of this study was to assess the morbidity of SSM-IBR after neoadjuvant CT and RT. METHODS: A French prospective pilot study of women aged 18-75 years with invasive breast cancer requiring mastectomy after CT and RT. Reconstruction was performed using autologous latissimus dorsi flap with or without prosthesis. The primary endpoint was the skin necrosis rate within 6 months, while secondary endpoints included pathological complete response rate (pCR) and global morbidity. RESULTS: Among 94 patients included in this study, 83 were analyzed (mean age 45.2 ± 9.5 years, T1 23.6 %, T2 55.6 %, T3 18.1 %). All but one patient received anthracyclines and taxanes, and all patients received RT (49.3 ± 5.2 Gy) before SSM-IBR. Prostheses were used for IBR in 32 patients (mean volume 256 ± 73 mm(3)). Five patients had necrosis (≤2 cm(2), 2-10 cm(2) and >10 cm(2), in three, one, and one cases, respectively), and they all recovered without revision surgery. Among 50 patients who underwent upfront mastectomy, 36 % achieved pCR. CONCLUSIONS: SSM-IBR performed after CT and RT is safe, with an acceptable local morbidity rate. Long-term data are needed to evaluate recurrence rates.


Asunto(s)
Neoplasias de la Mama/cirugía , Mamoplastia , Mastectomía , Tratamientos Conservadores del Órgano , Músculos Superficiales de la Espalda/cirugía , Colgajos Quirúrgicos , Adolescente , Adulto , Anciano , Neoplasias de la Mama/patología , Neoplasias de la Mama/terapia , Carcinoma Ductal de Mama/patología , Carcinoma Ductal de Mama/cirugía , Carcinoma Ductal de Mama/terapia , Carcinoma Lobular/patología , Carcinoma Lobular/cirugía , Carcinoma Lobular/terapia , Quimioterapia Adyuvante , Terapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Terapia Neoadyuvante , Invasividad Neoplásica , Proyectos Piloto , Pronóstico , Estudios Prospectivos , Radioterapia Adyuvante , Adulto Joven
8.
Nanoscale ; 16(22): 10607-10617, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38758111

RESUMEN

Maghemite nanoparticles functionalised with Co(II) coordination complexes at their surface show a significant increase of their magnetic anisotropy, leading to a doubling of the blocking temperature and a sixfold increase of the coercive field. Magnetometric studies suggest an enhancement that is not related to surface disordering, and point to a molecular effect involving magnetic exchange interactions mediated by the oxygen atoms at the interface as its source. Field- and temperature-dependent X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) studies show that the magnetic anisotropy enhancement is not limited to surface atoms and involves the core of the nanoparticle. These studies also point to a mechanism driven by anisotropic exchange and confirm the strength of the magnetic exchange interactions. The coupling between the complex and the nanoparticle persists at room temperature. Simulations based on the XMCD data give an effective exchange field value through the oxido coordination bridge between the Co(II) complex and the nanoparticle that is comparable to the exchange field between iron ions in bulk maghemite. Further evidence of the effectiveness of the oxido coordination bridge in mediating the magnetic interaction at the interface is given with the Ni(II) analog to the Co(II) surface-functionalised nanoparticles. A substrate-induced magnetic response is observed for the Ni(II) complexes, up to room temperature.

9.
Sci Rep ; 13(1): 2278, 2023 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-36755030

RESUMEN

The combined passive and active targeting of tumoral tissue remains an active and relevant cancer research field. Here, we exploit the properties of two highly magnetic nanomaterials, magnetosomes and ultramagnetic liposomes, in order to magnetically target prostate adenocarcinoma tumors, implanted orthotopically or subcutaneously, to take into account the role of tumor vascularization in the targeting efficiency. Analysis of organ biodistribution in vivo revealed that, for all conditions, both nanomaterials accumulate mostly in the liver and spleen, with an overall low tumor retention. However, both nanomaterials were more readily identified in orthotopic tumors, reflecting their higher tumor vascularization. Additionally, a 2- and 3-fold increase in nanomaterial accumulation was achieved with magnetic targeting. In summary, ultramagnetic nanomaterials show promise mostly in the targeting of highly-vascularized orthotopic murine tumor models.


Asunto(s)
Magnetosomas , Neoplasias de la Próstata , Masculino , Humanos , Animales , Ratones , Liposomas , Distribución Tisular , Neovascularización Patológica , Fenómenos Magnéticos , Línea Celular Tumoral
10.
Chem Commun (Camb) ; 58(37): 5642-5645, 2022 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-35439806

RESUMEN

Here, multivalent functions have been successfully integrated on a single core-shell type nanostructure, for remote-controlled and receptor-targeted intracellular delivery of doxorubicin (DOX) to breast cancer cells that overexpress biotin receptors.


Asunto(s)
Nanopartículas , Neoplasias , Línea Celular Tumoral , Doxorrubicina/química , Sistemas de Liberación de Medicamentos , Fenómenos Magnéticos , Polímeros Impresos Molecularmente , Nanopartículas/química , Neoplasias/tratamiento farmacológico
11.
ACS Appl Mater Interfaces ; 14(13): 15021-15034, 2022 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-35319860

RESUMEN

The endosomal entrapment of functional nanoparticles is a severe limitation to their use for biomedical applications. In the case of magnetic nanoparticles (MNPs), this entrapment leads to poor heating efficiency for magnetic hyperthermia and suppresses the possibility to manipulate them in the cytosol. Current strategies to limit their entrapment include functionalization with cell-penetrating peptides to promote translocation directly across the cell membrane or facilitate endosomal escape. However, these strategies suffer from the potential release of free peptides in the cell, and to the best of our knowledge, there is currently a lack of effective methods for the cytosolic delivery of MNPs after incubation with cells. Herein, we report the conjugation of fluorescently labeled cationic peptides to γ-Fe2O3@SiO2 core-shell nanoparticles by click chemistry to improve MNP access to the cytosol. We compare the effect of Arg9 and His4 peptides. On the one hand, Arg9 is a classical cell-penetrating peptide able to enter cells by direct translocation, and on the other hand, it has been demonstrated that sequences rich in histidine residues can promote endosomal escape, possibly by the proton sponge effect. The methodology developed here allows a high colocalization of the peptides and core-shell nanoparticles in cells and confirms that grafting peptides rich in histidine residues onto nanoparticles promotes NPs' access to the cytosol. Endosomal escape was confirmed by a calcein leakage assay and by ultrastructural analysis in transmission electron microscopy. No toxicity was observed for the peptide-nanoparticles conjugates. We also show that our conjugation strategy is compatible with the addition of multiple substrates and can thus be used for the delivery of cytoplasm-targeted therapeutics.


Asunto(s)
Péptidos de Penetración Celular , Nanopartículas , Péptidos de Penetración Celular/metabolismo , Citosol/metabolismo , Endosomas/metabolismo , Fenómenos Magnéticos , Nanopartículas/química , Dióxido de Silicio/metabolismo
12.
Commun Biol ; 5(1): 137, 2022 02 17.
Artículo en Inglés | MEDLINE | ID: mdl-35177769

RESUMEN

How mechanical stress actively impacts the physiology and pathophysiology of cells and tissues is little investigated in vivo. The colon is constantly submitted to multi-frequency spontaneous pulsatile mechanical waves, which highest frequency functions, of 2 s period, remain poorly understood. Here we find in vivo that high frequency pulsatile mechanical stresses maintain the physiological level of mice colon stem cells (SC) through the mechanosensitive Ret kinase. When permanently stimulated by a magnetic mimicking-tumor growth analogue pressure, we find that SC levels pathologically increase and undergo mechanically induced hyperproliferation and tumorigenic transformation. To mimic the high frequency pulsatile mechanical waves, we used a generator of pulsed magnetic force stimulation in colonic tissues pre-magnetized with ultra-magnetic liposomes. We observed the pulsatile stresses using last generation ultra-wave dynamical high-resolution imaging. Finally, we find that the specific pharmacological inhibition of Ret mechanical activation induces the regression of spontaneous formation of SC, of CSC markers, and of spontaneous sporadic tumorigenesis in Apc mutated mice colons. Consistently, in human colon cancer tissues, Ret activation in epithelial cells increases with tumor grade, and partially decreases in leaking invasive carcinoma. High frequency pulsatile physiological mechanical stresses thus constitute a new niche that Ret-dependently fuels mice colon physiological SC level. This process is pathologically over-activated in the presence of permanent pressure due to the growth of tumors initiated by pre-existing genetic alteration, leading to mechanotransductive self-enhanced tumor progression in vivo, and repressed by pharmacological inhibition of Ret.


Asunto(s)
Neoplasias del Colon/metabolismo , Proteínas Proto-Oncogénicas c-ret/metabolismo , Animales , Biomarcadores de Tumor , Línea Celular Tumoral , Transformación Celular Neoplásica , Femenino , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino , Ratones , Ratones Endogámicos , Células Madre Neoplásicas , Proteínas Proto-Oncogénicas c-ret/genética
13.
Front Psychol ; 12: 631186, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33897539

RESUMEN

BACKGROUND: Even though virtual reality (VR) is more and more considered for its power of distraction in different medical contexts, the optimal conditions for its use still have to be determined in order to design interfaces adapted to therapeutic support in oncology. OBJECTIVE: The objective of this study was to examine the benefits of VR using two immersion methods (i.e., one participatory, one contemplative) and comparing them with each other in a population of women with breast cancer who have undergone breast surgery, during scar massage sessions. METHODS: In a physiotherapy center, each patient participated in four experimental conditions in a random order: two sessions used virtual immersion (i.e., one participatory and one contemplative), one session proposed musical listening and the fourth one was a standard session care. The impact of the level of patient involvement in the virtual world was apprehended through the evaluation of the feeling of presence; the estimation of elapsed time of the physiotherapy sessions and particular attention was paid to the evaluation of patient emotional state. RESULTS: Our study showed an increase in positive emotions (i.e., joy and happiness) and a decrease in anxiety regardless which support methods were offered. Participatory VR created a feeling of more intense spatial presence. CONCLUSION: Our results highlight the importance of the context in which VR should be offered. The presence of the practitioner and his interactions with the patient can provide a context just as favorable in reducing anxiety as the emotional regulation tools used (VR, music). The use of technological tools should be favored when the practitioner is unavailable during the treatment phase or, even, in order to reduce the monotonous nature of repetitive therapeutic sessions.

14.
Chem Commun (Camb) ; 57(48): 5945-5948, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-34019041

RESUMEN

We describe a novel synthesis allowing one to enhance the load of magnetic nanoparticles and gold nanorods in nanogels. Two different structures, simple cores and core-shell, were synthesized and their heating properties upon alternating magnetic field or laser exposure are compared. Remarkably, the core-shell structure showed a greater heating capacity in the two modalities.


Asunto(s)
Oro/química , Nanopartículas de Magnetita/química , Nanogeles/química , Calefacción , Campos Magnéticos , Estructura Molecular , Tamaño de la Partícula , Procesos Fotoquímicos , Propiedades de Superficie
15.
Nanomaterials (Basel) ; 10(8)2020 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-32784579

RESUMEN

The photothermal use of iron oxide magnetic nanoparticles (NPs) is becoming more and more popular and documented. Herein, we compared the photothermal (PT) therapy potential versus magnetic hyperthermia (MHT) modality of magnetic nanospheres, largely used in the biomedical field and magnetic multicore nanoflowers known among the best nanoheaters. The NPs were imaged using transmission electron microscopy and their optical properties characterized by UV-Vis-NIR-I-II before oxidation (magnetite) and after oxidation to maghemite. The efficiency of all NPs in MHT and PT in the preferred second near-infrared (NIR-II) biological window was carried out in water and in cancer cells. We show that, in water, magnetite nanoflowers are the most efficient nanoheaters for both modalities. Moreover, PT appears much more efficient than MHT at low NP dose, whatever the NP. In the cellular environment, for PT, efficiency was totally conserved, with magnetite nanoflowers as the best performers compared to MHT, which was totally lost. Finally, cell uptake was significantly increased for the nanoflowers compared to the nanospheres. Finally, the antitumor therapy was investigated for all NPs at the same dose delivered to the cancer cells and at reasonable laser power density (0.3 W/cm2), which showed almost total cell death for magnetite nanoflowers.

16.
J Control Release ; 322: 137-148, 2020 06 10.
Artículo en Inglés | MEDLINE | ID: mdl-32145266

RESUMEN

Theranostic nanocarriers of antivascular drug encapsulated in thermosensitive ultramagnetic liposomes can be advantageously designed to provide a locally high concentration and an active delivery, with image-guided Magnetic Resonance Imaging (MRI) so as to reliably cure tumor. We propose a novel therapeutic strategy consisting of the magnetic accumulation of Ultra Magnetic Liposomes (UML) followed by High-Intensity Focused Ultrasound (HIFU) to trigger the release of an antivascular agent monitored by MRI. For this purpose, we co-encapsulated Combretastatin A4 phosphate (CA4P), a vascular disrupting agent, in the core of UML to obtain CA4P-loaded thermosensitive Ultra Magnetic Liposomes (CA4P-UML). To assess the HIFU parameters, the CA4P release has been triggered in vitro by local heating HIFU at the lipids transition temperature. Morphology of endothelial cells was assessed to evaluate the effect of encapsulated versus non-encapsulated CA4P. The efficiency of a treatment combining the magnetic targeting of CA4P-UML with the CA4P release triggered by HIFU was studied in CT26 murine tumors. Tumor perfusion and volume regression parameters were monitored by multiparametric quantitative anatomical and dynamic in vivo MRI at 7 T. Additionally, vascularization and cellularity were evaluated ex-vivo by histology. This thorough investigation showed that the combined treatment exhibited a full benefit. A 150-fold improvement compared with the chemotherapy alone was obtained using a magnetic targeting of CA4P-UML triggered by HIFU, and was consistent with an expected effect on vascularization 24 h after treatment.


Asunto(s)
Liposomas , Estilbenos , Animales , Medios de Contraste , Células Endoteliales , Imagen por Resonancia Magnética , Ratones , Medicina de Precisión
17.
J Chromatogr A ; 1609: 460433, 2020 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-31427136

RESUMEN

In this work, interactions of carboxylated core shell magnetic nanoparticles with polymyxin B sulfate were studied by connecting capillary electrophoresis with inductively coupled plasma mass spectrometry. The interaction was probed by affinity mode of capillary electrophoresis with 25 mM phosphate buffer at physiological pH. 54Fe, 56Fe, 57Fe, 34S, and 12C isotopes were used to monitor the migration of an electroosmotic flow marker and the interaction of the nanoparticles with polymyxin B. The analysis of interaction data showed two distinct interaction regions, one with low polymyxin B concentration, the second with high polymyxin B concentration. These regions differed in the strength of the interaction, 1.49 × 107 M-1 and 1.60 × 104 M-1, and in the stoichiometry of 0.7 and 3.5, respectively. These differences can be explained by the decrease of electrostatic repulsion between nanoparticles caused by polymyxin B. This is also in agreement with the nanoparticles peak shapes: sharp for low polymyxin B concentrations and broad for high polymyxin B concentrations.


Asunto(s)
Electroforesis Capilar/métodos , Nanopartículas de Magnetita/química , Espectrometría de Masas/métodos , Polimixina B/análisis , Presión
18.
Sci Rep ; 10(1): 22452, 2020 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-33384447

RESUMEN

The axon regeneration of neurons in the brain can be enhanced by activating intracellular signaling pathways such as those triggered by the membrane-anchored Rat sarcoma (RAS) proto-oncogene. Here we demonstrate the induction of neurite growth by expressing tagged permanently active Harvey-RAS protein or the RAS-activating catalytic domain of the guanine nucleotide exchange factor (SOS1cat), in secondary dopaminergic cells. Due to the tag, the expressed fusion protein is captured by functionalized magnetic nanoparticles in the cytoplasm of the cell. We use magnetic tips for remote translocation of the SOS1cat-loaded magnetic nanoparticles from the cytoplasm towards the inner face of the plasma membrane where the endogenous Harvey-RAS protein is located. Furthermore, we show the magnetic transport of SOS1cat-bound nanoparticles from the cytoplasm into the neurite until they accumulate at its tip on a time scale of minutes. In order to scale-up from single cells, we show the cytoplasmic delivery of the magnetic nanoparticles into large numbers of cells without changing the cellular response to nerve growth factor. These results will serve as an initial step to develop tools for refining cell replacement therapies based on grafted human induced dopaminergic neurons loaded with functionalized magnetic nanoparticles in Parkinson model systems.


Asunto(s)
Neuronas Dopaminérgicas/metabolismo , Nanopartículas de Magnetita , Regeneración Nerviosa , Neuritas/metabolismo , Proteína SOS1/metabolismo , Biomarcadores , Línea Celular , Técnica del Anticuerpo Fluorescente , Expresión Génica , Vectores Genéticos/genética , Humanos , Modelos Biológicos , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Proteína SOS1/genética
19.
Pharmaceutics ; 12(9)2020 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-32911863

RESUMEN

Cationic liposomes have been considered as potential vectors for gene delivery thanks to their ability to transfect cells with high efficiency. Recently, the combination of diagnostic agent and therapeutic agents in the same particle to form a theranostic system has been reported. Magnetic liposomes are one of these examples. Due to the magnetic nanoparticles encapsulated in the liposomes, they can act as a drug delivery system and, at the same time, a magnetic resonance imaging contrast enhancement agent or hyperthermia. In this work, nucleic acid delivery systems based on magnetic cationic liposomes (MCLs) were developed. Two different techniques, reverse phase evaporation and cosolvent sonication, were employed for liposome preparation. Both strategies produced MCLs of less than 200 nm with highly positive charge. Enhancement of their transverse and longitudinal relaxivities r2and r1 was obtained with both kinds of magnetic liposomes compared to free magnetic nanoparticles. Moreover, these MCLs showed high capacity to form complexes and transfect CT-26 cells using the antibiotic-free pFAR4-luc plasmid. The transfection enhancement with magnetofection was also carried out in CT26 cells. These results suggested that our MCLs could be a promising candidate for image-guided gene therapy.

20.
Chem Commun (Camb) ; 56(70): 10255-10258, 2020 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-32756712

RESUMEN

Herein, we report a facile and rapid one-step synthetic strategy for the development of magnetic doxorubicin imprinted silica nanoparticles for drug release experiments in living cells showing a remotely triggered doxorubicin release upon applying an alternating magnetic field, without temperature elevation of the medium (local heating).


Asunto(s)
Doxorrubicina/química , Portadores de Fármacos/química , Campos Magnéticos , Nanopartículas/química , Dióxido de Silicio/química , Línea Celular Tumoral , Doxorrubicina/farmacología , Liberación de Fármacos , Humanos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA