RESUMEN
Recently, the azepino[4,3-b]indole-1-one derivative 1 showed in vitro nanomolar inhibition against butyrylcholinesterase (BChE), the ChE isoform that plays a role in the progression and pathophysiology of Alzheimer's disease (AD), and protects against N-methyl- d-aspartate-induced neuronal toxicity. Three 9-R-substituted (R = F, Br, OMe) congeners were investigated. The 9-F derivative (2a) was found more potent as BChE inhibitors (half-maximal inhibitory concentration value = 21 nM) than 2b (9-Br) and 2c (9-OMe), achieving a residence time (38 s), assessed by surface plasmon resonance, threefold higher than that of 1. To progress in featuring the in vivo pharmacological characterization of 2a, herein the 18 F-labeled congener 2a was synthesized, by applying the aromatic 18 F-fluorination method, and its whole-body distribution in healthy mice, including brain penetration, was evaluated through positron emission tomography imaging. [18 F]2a exhibited a rapid and high brain uptake (3.35 ± 0.26% ID g-1 at 0.95 ± 0.15 min after injection), followed by a rapid clearance (t1/2 = 6.50 ± 0.93 min), showing good blood-brain barrier crossing. After a transient liver accumulation of [18 F]2a, the intestinal and urinary excretion was quantified. Finally, ex vivo pharmacological experiments in mice showed that the unlabeled 2a affects the transmitters' neurochemistry, which might be favorable to reverse cognition impairment in mild-to-moderate AD-related dementias.
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Enfermedad de Alzheimer , Animales , Ratones , Enfermedad de Alzheimer/tratamiento farmacológico , Butirilcolinesterasa , Relación Estructura-Actividad , Transporte Biológico , IndolesRESUMEN
Vitamin D, an essential micronutrient crucial for skeletal integrity and various non-skeletal physiological functions, exhibits limited bioavailability and stability in vivo. This study is focused on the development of polyethylene glycol (PEG)-grafted phospholipid micellar nanostructures co-encapsulating vitamin D3 and conjugated with alendronic acid, aimed at active bone targeting. Furthermore, these nanostructures are rendered optically traceable in the UV-visible region of the electromagnetic spectrum via the simultaneous encapsulation of vitamin D3 with carbon dots, a newly emerging class of fluorescents, biocompatible nanoparticles characterized by their resistance to photobleaching and environmental friendliness, which hold promise for future in vitro bioimaging studies. A systematic investigation is conducted to optimize experimental parameters for the preparation of micellar nanostructures with an average hydrodynamic diameter below 200 nm, ensuring colloidal stability in physiological media while preserving the optical luminescent properties of the encapsulated carbon dots. Comprehensive chemical-physical characterization of these micellar nanostructures is performed employing optical and morphological techniques. Furthermore, their binding affinity for the principal inorganic constituent of bone tissue is assessed through a binding assay with hydroxyapatite nanoparticles, indicating significant potential for active bone-targeting. These formulated nanostructures hold promise for novel therapeutic interventions to address skeletal-related complications in cancer affected patients in the future.
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Alendronato , Huesos , Colecalciferol , Micelas , Nanoestructuras , Colecalciferol/química , Nanoestructuras/química , Huesos/efectos de los fármacos , Huesos/metabolismo , Alendronato/química , Polietilenglicoles/química , Humanos , Sistemas de Liberación de Medicamentos , Luminiscencia , Nanopartículas/química , Portadores de Fármacos/química , Puntos Cuánticos/químicaRESUMEN
Sigma-2 receptor (S2R) is a S2R ligand-binding site historically associated with reportedly 21.5 kDa proteins that have been linked to several diseases, such as cancer, Alzheimer's disease, and schizophrenia. The S2R is highly expressed in various tumors, where it correlates with the proliferative status of the malignant cells. Recently, S2R was reported to be the transmembrane protein TMEM97. Prior to that, we had been investigating the translocator protein (TSPO) as a potential 21.5 kDa S2R candidate protein with reported heme and sterol associations. Here, we investigate the contributions of TMEM97 and TSPO to S2R activity in MCF7 breast adenocarcinoma and MIA PaCa-2 (MP) pancreatic carcinoma cells. Additionally, the role of the reported S2R-interacting partner PGRMC1 was also elucidated. Proximity ligation assays and co-immunoprecipitation show a functional association between S2R and TSPO. Moreover, a close physical colocalization of TMEM97 and TSPO was found in MP cells. In MCF7 cells, co-immunoprecipitation only occurred with TMEM97 but not with PGRMC1, which was further confirmed by confocal microscopy experiments. Treatment with the TMEM97 ligand 20-(S)-hydroxycholesterol reduced co-immunoprecipitation of both TMEM97 and PGRMC1 in immune pellets of immunoprecipitated TSPO in MP cells. To the best of our knowledge, this is the first suggestion of a (functional) interaction between TSPO and TMEM97 that can be affected by S2R ligands.
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Receptores sigma , Humanos , Ligandos , Unión Proteica , Receptores sigma/metabolismo , Sitios de Unión , Receptores de GABA/metabolismo , Proteínas de la Membrana/metabolismo , Receptores de Progesterona/metabolismoRESUMEN
PURPOSE: Translocator protein 18-kDa (TSPO) positron emission tomography (PET) is a valuable tool to detect neuroinflammed areas in a broad spectrum of neurodegenerative diseases. However, the clinical application of second-generation TSPO ligands as biomarkers is limited because of the presence of human rs6971 polymorphism that affects their binding. Here, we describe the ability of a new TSPO ligand, [18F]BS224, to identify abnormal TSPO expression in neuroinflammation independent of the rs6971 polymorphism. METHODS: An in vitro competitive inhibition assay of BS224 was conducted with [3H]PK 11195 using membrane proteins isolated from 293FT cells expressing TSPO-wild type (WT) or TSPO-mutant A147T (Mut), corresponding to a high-affinity binder (HAB) and low-affinity binder (LAB), respectively. Molecular docking was performed to investigate the interaction of BS224 with the binding sites of rat TSPO-WT and TSPO-Mut. We synthesized a new 18F-labeled imidazopyridine acetamide ([18F]BS224) using boronic acid pinacol ester 6 or iodotoluene tosylate precursor 7, respectively, via aromatic 18F-fluorination. Dynamic PET scanning was performed up to 90 min after the injection of [18F]BS224 to healthy mice, and PET imaging data were obtained to estimate its absorbed doses in organs. To evaluate in vivo TSPO-specific uptake of [18F]BS224, lipopolysaccharide (LPS)-induced inflammatory and ischemic stroke rat models were used. RESULTS: BS224 exhibited a high affinity (Ki = 0.51 nM) and selectivity for TSPO. The ratio of IC50 values of BS224 for LAB to that for HAB indicated that the TSPO binding affinity of BS224 has low binding sensitivity to the rs6971 polymorphism and it was comparable to that of PK 11195, which is not sensitive to the polymorphism. Docking simulations showed that the binding mode of BS224 is not affected by the A147T mutation and consequently supported the observed in vitro selectivity of [18F]BS224 regardless of polymorphisms. With optimal radiochemical yield (39 ± 6.8%, decay-corrected) and purity (> 99%), [18F]BS224 provided a clear visible image of the inflammatory lesion with a high signal-to-background ratio in both animal models (BPND = 1.43 ± 0.17 and 1.57 ± 0.37 in the LPS-induced inflammatory and ischemic stroke rat models, respectively) without skull uptake. CONCLUSION: Our results suggest that [18F]BS224 may be a promising TSPO ligand to gauge neuroinflammatory disease-related areas in a broad range of patients irrespective of the common rs6971 polymorphism.
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Tomografía de Emisión de Positrones , Receptores de GABA , Animales , Proteínas Portadoras , Humanos , Ligandos , Ratones , Simulación del Acoplamiento Molecular , Radiofármacos , Ratas , Receptores de GABA/genética , Receptores de GABA/metabolismo , Receptores de GABA-ARESUMEN
Two new Pt(II)-pyrophosphato complexes containing the carrier ligands cis-1,3-diaminocyclohexane (cis-1,3-DACH) and trans-1,2-diamine-4-cyclohexene (1,2-DACHEX), variants of the 1R,2R-diaminocyclohexane ligand present in the clinically used Pt-drug oxaliplatin, have been synthesized with the aim of developing new potential antitumor drugs with high bone tropism. The complexes are more stable at physiological pH than in acid conditions, with Na2[Pt(pyrophosphato)(cis-1,3-DACH)] (1) slightly more stable than [Pt(dihydrogenpyrophosphato)(1,2-DACHEX)] (2). The greater reactivity at acidic pH ensures a greater efficacy at the tumor site. Preliminary NMR studies indicate that 1 and 2 react slowly with 5'-GMP (used as a model of nucleic acids), releasing the pyrophosphate ligand and affording the bis 5'-GMP adduct. In vitro cytotoxicity assays performed against a panel of four human cancer cell lines have shown that both compounds are more active than oxaliplatin. Flow cytometry studies on HCT116 cells showed that the pyrophosphato compounds with the non-classical 1,3- and 1,4-diaminocyclohexane ligands (1 and 4) are the most capable to induce cells' death by apoptosis and necrosis.
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Antineoplásicos/farmacología , Cisplatino/farmacología , Compuestos Organoplatinos/farmacología , Oxaliplatino/análogos & derivados , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Femenino , Células HCT116 , Humanos , Concentración de Iones de Hidrógeno , Masculino , Estructura Molecular , Compuestos Organoplatinos/síntesis química , Compuestos Organoplatinos/química , Células PC-3RESUMEN
Friedreich ataxia (FRDA) is an inherited recessive disorder caused by a deficiency in the mitochondrial protein frataxin. There is currently no effective treatment for FRDA available, especially for neurological deficits. In this study, we tested diazoxide, a drug commonly used as vasodilator in the treatment of acute hypertension, on cellular and animal models of FRDA. We first showed that diazoxide increases frataxin protein levels in FRDA lymphoblastoid cell lines, via the mammalian target of rapamycin (mTOR) pathway. We then explored the potential therapeutic effect of diazoxide in frataxin-deficient transgenic YG8sR mice and we found that prolonged oral administration of 3 mpk/d diazoxide was found to be safe, but produced variable effects concerning efficacy. YG8sR mice showed improved beam walk coordination abilities and footprint stride patterns, but a generally reduced locomotor activity. Moreover, they showed significantly increased frataxin expression, improved aconitase activity, and decreased protein oxidation in cerebellum and brain mitochondrial tissue extracts. Further studies are needed before this drug should be considered for FRDA clinical trials.
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Diazóxido/farmacología , Ataxia de Friedreich/tratamiento farmacológico , Proteínas de Unión a Hierro/efectos de los fármacos , Animales , Línea Celular , Células Cultivadas , Modelos Animales de Enfermedad , Ataxia de Friedreich/metabolismo , Humanos , Ratones , Ratones Transgénicos , Mitocondrias/metabolismo , Proteínas Mitocondriales/metabolismo , FrataxinaRESUMEN
Efforts are made to perform an early and accurate detection of hepatocellular carcinoma (HCC) by simultaneous exploiting multiple clinically non-invasive imaging modalities. Original nanostructures derived from the combination of different inorganic domains can be used as efficient contrast agents in multimodal imaging. Superparamagnetic iron oxide nanoparticles (SPIONs) and Au nanoparticles (NPs) possess well-established contrasting features in magnetic resonance imaging (MRI) and X-ray computed tomography (CT), respectively. HCC can be targeted by using specific carbohydrates able to recognize asialoglycoprotein receptor 1 (ASGPR1) overexpressed in hepatocytes. Here, two different thiocarbohydrate ligands were purposely designed and alternatively conjugated to the surface of Au-speckled silica-coated SPIONs NPs, to achieve two original nanostructures that could be potentially used for dual mode targeted imaging of HCC. The results indicated that the two thiocarbohydrate decorated nanostructures possess convenient plasmonic/superparamagnetic properties, well-controlled size and morphology and good selectivity for targeting ASGPR1 receptor.
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Receptor de Asialoglicoproteína/metabolismo , Carbohidratos/química , Carcinoma Hepatocelular/diagnóstico por imagen , Oro , Nanopartículas Magnéticas de Óxido de Hierro/química , Nanopartículas del Metal/química , Dióxido de Silicio , Compuestos de Sulfhidrilo/química , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Imagen por Resonancia MagnéticaRESUMEN
The development of medicines designed for children can be challenging since this distinct patient population requires specific needs. A formulation designed for paediatric patients must consider the following aspects: patient population variability; dose flexibility; route of administration; patient compliance; drug and excipient tolerability. The purpose of this Special Issue entitled "Paediatric Formulation: Design and Development" is to provide an update on both state-of-the-art methodology and operational challenges in the design and development of paediatric formulations. It aims at re-evaluating what is needed for more progress in the design and development of age-appropriate treatments for paediatric diseases, focusing on: formulation development; drug delivery design; efficacy, safety, and tolerability of drugs and excipients. This editorial, briefly, summarizes the objects of nine original research and review papers published in this Special Issue.
Asunto(s)
Química Farmacéutica , Composición de Medicamentos , Sistemas de Liberación de Medicamentos , Desarrollo de Medicamentos , Niño , Excipientes/química , Excipientes/uso terapéutico , Humanos , Publicaciones Periódicas como AsuntoRESUMEN
The therapeutic approach to Chronic Myeloid Leukemia (CML) has changed since the advent of the tyrosine kinase inhibitor (TKI) imatinib, which was then followed by the second generation TKIs dasatinib, nilotinib, and, finally, by ponatinib, a third-generation drug. At present, these therapeutic options represent the first-line treatment for adults. Based on clinical experience, imatinb, dasatinib, and nilotinib have been approved for children even though the studies that were concerned with efficacy and safety toward pediatric patients are still awaiting more specific and high-quality data. In this scenario, it is of utmost importance to prospectively validate data extrapolated from adult studies to set a standard therapeutic management for pediatric CML by employing appropriate formulations on the basis of pediatric clinical trials, which allow a careful monitoring of TKI-induced adverse effects especially in growing children exposed to long-term therapy.
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Proteínas de Fusión bcr-abl/antagonistas & inhibidores , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico , Niño , Proteínas de Fusión bcr-abl/genética , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , PronósticoRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies, with poor outcomes largely due to its unique microenvironment, which is responsible for the low response to drugs and drug-resistance phenomena. This clinical need led us to explore new therapeutic approaches for systemic PDAC treatment by the utilization of two newly synthesized biphenylnicotinamide derivatives, PTA73 and PTA34, with remarkable antitumor activity in an in vitro PDAC model. Given their poor water solubility, inclusion complexes of PTA34 and PTA73 in Hydroxy-Propil-ß-Cyclodextrin (HP-ß-CD) were prepared in solution and at the solid state. Complexation studies demonstrated that HP-ß-CD is able to form stable host-guest inclusion complexes with PTA34 and PTA73, characterized by a 1:1 apparent formation constant of 503.9 M-1 and 369.2 M-1, respectively (also demonstrated by the Job plot), and by an increase in aqueous solubility of about 150 times (from 1.95 µg/mL to 292.5 µg/mL) and 106 times (from 7.16 µg/mL to 762.5 µg/mL), in the presence of 45% w/v of HP-ß-CD, respectively. In vitro studies confirmed the high antitumor activity of the complexed PTA34 and PTA73 towards PDAC cells, the strong G2/M phase arrest followed by induction of apoptosis, and thus their eligibility for PDAC therapy.
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2-Hidroxipropil-beta-Ciclodextrina/química , 2-Hidroxipropil-beta-Ciclodextrina/farmacología , Compuestos de Bifenilo/farmacología , Compuestos de Bifenilo/química , Carcinoma Ductal Pancreático/tratamiento farmacológico , Carcinoma Ductal Pancreático/metabolismo , Línea Celular Tumoral/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Química Farmacéutica/métodos , Composición de Medicamentos/métodos , Humanos , Cuerpos de Inclusión/metabolismo , Espectroscopía de Resonancia Magnética/métodos , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/metabolismo , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Microambiente Tumoral/efectos de los fármacos , Difracción de Rayos X/métodos , beta-Ciclodextrinas/metabolismo , beta-Ciclodextrinas/farmacologíaRESUMEN
New scientific findings have recently shown that dasatinib (DAS), the first-choice oral drug in the treatment of chronic myeloid leukemia (CML) for adult patients who are resistant or intolerant to imatinib, is also potentially useful in the paediatric age. Moreover, recent preclinical evidences suggest that this drug could be useful for the treatment of Duchenne muscular dystrophy, since it targets cSrc tyrosin kinase. Based on these considerations, the purpose of this work was to use the strategy of complexation with hydroxypropyl-ß-cyclodextrin (HP-ß-CD) in order to obtain an aqueous preparation of DAS, which is characterized by a low water solubility (6.49 × 10-4 mg/mL). Complexation studies demonstrated that HP-ß-CD is able to form a stable host-guest inclusion complex with DAS with a 1:1 apparent formation constant of 922.13 M-1, as also demonstrated by the Job's plot, with an increase in DAS aqueous solubility of about 21 times in the presence of 6% w/v of HP-ß-CD (0.014 mg/mL). The inclusion complex has been prepared in the solid state by lyophilization and characterized by Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (NMR), Differential Scanning Calorimetry (DSC) techniques, and its dissolution profile was studied at different pH values. Moreover, in view of potential use of DAS for Duchenne muscular dystrophy, the cytotoxic effect of the inclusion complex has been assessed on C2C12 cells, a murine muscle satellite cell line. In parallel, a one-week oral treatment was performed in wild type C57Bl/6J mice to test both palatability and the exposure levels of the new oral formulation of the compound. In conclusion, this new inclusion complex could allow the development of a liquid and solvent free formulation to be administered both orally and parenterally, especially in the case of an administration in paediatric age.
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2-Hidroxipropil-beta-Ciclodextrina/química , Dasatinib/química , Enfermedades Neuromusculares/tratamiento farmacológico , Animales , Rastreo Diferencial de Calorimetría , Línea Celular , Cromatografía Líquida de Alta Presión , Espectroscopía de Resonancia Magnética , Masculino , Ratones , Ratones Endogámicos C57BL , Distrofia Muscular de Duchenne , Solubilidad , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
The low photostability of conventional organic dyes and the toxicity of cadmium-based luminescent quantum dots have prompted the development of novel probes for in vitro and in vivo labelling. Here, a new fluorescent lanthanide probe based on silica nanoparticles is fabricated and investigated for optically traceable in vitro translocator protein (TSPO) targeting. The targeting and detection of TSPO receptor, overexpressed in several pathological states, including neurodegenerative diseases and cancers, may provide valuable information for the early diagnosis and therapy of human disorders. Green fluorescent terbium(III)-calix[4]arene derivative complexes are encapsulated within silica nanoparticles and surface functionalized amine groups are conjugated with selective TSPO ligands based on a 2-phenylimidazo[1,2-a]pyridine acetamide structure containing derivatizable carboxylic groups. The photophysical properties of the terbium complex, promising for biological labelling, are demonstrated to be successfully conveyed to the realized nanoarchitectures. In addition, the high degree of biocompatibility, assessed by cell viability assay and the selectivity towards TSPO mitochondrial membrane receptors, proven by subcellular fractional studies, highlight targeting potential of this nanostructure for in vitro labelling of mitochondria.
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Colorantes Fluorescentes/química , Nanopartículas/química , Dióxido de Silicio/química , Terbio/química , Calixarenos/química , Línea Celular Tumoral , Colorantes Fluorescentes/farmacología , Humanos , Ligandos , Fenoles/química , Unión Proteica , Receptores de GABA/efectos de los fármacos , Receptores de GABA/metabolismoRESUMEN
Autoinflammatory diseases (AIDs) are heterogeneous disorders characterized by dysregulation in the inflammasome, a large intracellular multiprotein platform, leading to overproduction of interleukin-1(IL-1)ß that plays a predominant pathogenic role in such diseases. Appropriate treatment is crucial, also considering that AIDs may persist into adulthood with negative consequences on patients' quality of life. IL-1ß blockade results in a sustained reduction of disease severity in most AIDs. A growing experience with the human IL-1 receptor antagonist, Anakinra (ANA), and the monoclonal anti IL-1ß antibody, Canakinumab (CANA), has also been engendered, highlighting their efficacy upon protean clinical manifestations of AIDs. Safety and tolerability have been confirmed by several clinical trials and observational studies on both large and small cohorts of AID patients. The same treatment has been proposed in refractory Kawasaki disease, an acute inflammatory vasculitis occurring in children before 5 years, which has been postulated to be autoinflammatory for its phenotypical and immunological similarity with systemic juvenile idiopathic arthritis. Nevertheless, minor concerns about IL-1 antagonists have been raised regarding their employment in children, and the development of novel pharmacological formulations is aimed at minimizing side effects that may affect adherence to treatment. The present review summarizes current findings on the efficacy, safety, and tolerability of ANA and CANA for treatment of AIDs and Kawasaki vasculitis with a specific focus on the pediatric setting.
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Anticuerpos Monoclonales/uso terapéutico , Artritis Juvenil/tratamiento farmacológico , Síndromes Periódicos Asociados a Criopirina/tratamiento farmacológico , Fiebre Mediterránea Familiar/tratamiento farmacológico , Fiebre/tratamiento farmacológico , Enfermedades Autoinflamatorias Hereditarias/tratamiento farmacológico , Proteína Antagonista del Receptor de Interleucina 1/uso terapéutico , Deficiencia de Mevalonato Quinasa/tratamiento farmacológico , Síndrome Mucocutáneo Linfonodular/tratamiento farmacológico , Animales , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales Humanizados , Artritis Juvenil/inmunología , Síndromes Periódicos Asociados a Criopirina/inmunología , Fiebre Mediterránea Familiar/inmunología , Fiebre/inmunología , Enfermedades Autoinflamatorias Hereditarias/inmunología , Humanos , Proteína Antagonista del Receptor de Interleucina 1/efectos adversos , Interleucina-1beta/inmunología , Deficiencia de Mevalonato Quinasa/inmunología , Síndrome Mucocutáneo Linfonodular/inmunología , Receptores de Interleucina-1/antagonistas & inhibidoresRESUMEN
The increasing importance of sigma-2 receptor as target for the diagnosis and therapy of tumors paves the way for the development of innovative optically traceable fluorescent probes as tumor cell contrast and therapeutic agents. Here, a novel hybrid organic-inorganic nanostructure is developed by combining the superior fluorescent properties of inorganic quantum dots (QDs), coated with a hydrophilic silica shell (QD@SiO2 NPs), the versatility of the silica shell, and the high selectivity for sigma-2 receptor of the two synthetic ligands, namely, the 6-[(6-aminohexyl)oxy]-2-(3-(6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)propyl)-3,4-dihydroisoquinolin-1(2H)-one (MLP66) and 6-[1-[3-(4-cyclohexylpiperazin-1-yl)propyl]-1,2,3,4-tetrahydronaphthalen-5-yloxy]hexylamine (TA6). The proposed nanostructures represent a challenging alternative to all previously studied organic small fluorescent molecules, based on the same sigma-2 receptor affinity moieties. Flow cytometry and confocal fluorescence microscopy experiments, respectively, on fixed and living cancerous MCF7 cells, which overexpress the sigma-2 receptor, prove the ability of functionalized (QD@SiO2-TA6 and QD@SiO2-MLP66) NPs to be internalized and demonstrate their affinity to the sigma-2 receptor, ultimately validating the targeting properties conveyed to the NPs by sigma-2 ligand conjugation. The presented QD-based nanoprobes possess a great potential as in vitro selective sigma-2 receptor imaging agent and, consequently, could provide a significant impact to future theranostic applications.
Asunto(s)
Imagen Molecular/métodos , Neoplasias/diagnóstico por imagen , Puntos Cuánticos/química , Receptores sigma/metabolismo , Nanomedicina Teranóstica/métodos , Citometría de Flujo , Colorantes Fluorescentes/química , Colorantes Fluorescentes/metabolismo , Humanos , Ligandos , Células MCF-7 , Microscopía Confocal , Microscopía Fluorescente , Sondas Moleculares/química , Sondas Moleculares/metabolismo , Nanoestructuras/química , Neoplasias/patología , Puntos Cuánticos/metabolismo , Dióxido de Silicio/químicaRESUMEN
We designed and synthesized deuterium-substituted [18F]fluoromethyl-PBR28 ([18F]1-d2) as a novel translocator protein 18â¯kDa (TSPO)-targeted radioligand with enhanced in vivo stability. The comparison studies between [18F]fluoromethyl-PBR28 ([18F]1) and its deuterate analog ([18F]1-d2) were investigated in terms of in vitro binding affinity, lipophilicity and in vivo stability. In addition, the accuracies of both radioligands were determined by comparing the PET imaging data in the same LPS-induced neuroinflammation rat model. Both aryloxyanilide analogs showed similar lipophilicity and in vitro affinity for TSPO. However, [18F]1-d2 provided significantly lower femur uptake than [18F]1 (1.5⯱â¯1.2 vs. 4.1⯱â¯1.7%ID/g at 2â¯h post-injection) in an ex vivo biodistribution study. [18F]1-d2 was also selectively accumulated in the inflammatory lesion with the binding potential of the specifically bound radioligand relative to the non-displaceable radioligand in tissue (BPNDâ¯=â¯3.17⯱â¯0.48), in a LPS-induced acute neuroinflammation rat model, comparable to that of [18F]1 (BPNDâ¯=â¯2.13⯱â¯0.51). These results indicate that [18F]1-d2 had higher in vivo stability, which resulted in an enhanced target-to-background ratio compared to that induced by [18F]1.
Asunto(s)
Acetamidas/farmacocinética , Aminopiridinas/farmacocinética , Modelos Animales de Enfermedad , Inflamación/diagnóstico por imagen , Enfermedades Neurodegenerativas/diagnóstico por imagen , Radiofármacos/farmacocinética , Acetamidas/síntesis química , Acetamidas/química , Aminopiridinas/síntesis química , Aminopiridinas/química , Animales , Relación Dosis-Respuesta a Droga , Flumazenil/química , Flumazenil/farmacocinética , Inflamación/inducido químicamente , Inflamación/metabolismo , Lipopolisacáridos , Masculino , Ratones , Ratones Endogámicos ICR , Estructura Molecular , Enfermedades Neurodegenerativas/inducido químicamente , Enfermedades Neurodegenerativas/metabolismo , Tomografía de Emisión de Positrones , Radiofármacos/síntesis química , Radiofármacos/química , Ratas , Relación Estructura-Actividad , Distribución TisularRESUMEN
Translocator protein 18-kDa (TSPO) is a versatile mitochondrial target for molecular imaging and therapy. Moreover, selective TSPO ligands have been widely investigated for diagnostic purposes and explored to target drug delivery systems directed to cancer cells overexpressing TSPO. Indeed, poly(d,l-lactic-co-glycolic acid (PLGA) polymers and nanocarriers decorated with TSPO ligands are capable of transporting TSPO ligands inside cancer cells, inducing survival inhibition in cancer cells and producing mitochondrial morphology modification. The aim of this work was to prepare nanogels (NGs) made with TSPO ligand dextran conjugates (TSPO-Dex) that are useful as potential delivery systems of two TSPO ligands as apoptotic agents. Synthesis and complete characterization of TSPO-dextran conjugates, an average molecular weights analysis, TSPO ligand release profiles, thermal behaviour and swelling studies were achieved. NG preparation, characterization and in vitro biological studies were also performed. The release of TSPO ligands released from dextran conjugates at 37 °C occurred in human serum at a faster rate than that detected in phosphate buffer. Cytotoxicity studies demonstrated that NGs produced from TSPO ligand-dextran conjugates induce survival inhibition in rat C6 glioma cell lines. Cellular uptake was also proven by fluorescence microscopy.
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Antineoplásicos/administración & dosificación , Apoptosis/efectos de los fármacos , Dextranos/química , Portadores de Fármacos/síntesis química , Hidrogeles/química , Receptores de GABA/metabolismo , Animales , Antineoplásicos/farmacología , Línea Celular Tumoral , Células Cultivadas , Liberación de Fármacos , Glioma/metabolismo , Humanos , Ácido Láctico/química , Ligandos , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Unión Proteica , RatasRESUMEN
Overexpression of the 18-kDa translocator protein (TSPO) is closely linked to inflammatory responses in the heart, including myocarditis, which can lead to myocardial necrosis. In vivo assessment of inflammatory responses has enabled the precise diagnosis of myocarditis to improve clinical outcomes. Here, we evaluated TSPO overexpression in a rat model of experimental autoimmune myocarditis (EAM) compared to healthy rats using two TSPO radiotracers, [18F]fluoromethyl-PBR28 ([18F]1) and [18F]CB251 ([18F]2). All radiolabeling methods were successfully applied to an automated module for the reproducible preparation of TSPO radiotracers. Both radiotracers were directly compared in an EAM rat model, as well as in healthy rats to determine whether either radiotracer provides a more promising assessment of in vivo TSPO overexpression. [18F]2 provided more specific TSPO-uptake in the heart of the EAM rats (1.32-fold that of the heart-to-lung uptake ratio versus healthy controls), while [18F]1 did not show a significant difference between the two groups. Histopathological characterization revealed that a prominent positron emission tomography (PET) signal of [18F]2 in the EAM rats corresponded to the presence of a higher density of TSPO compared to the healthy controls. These results suggest that the imidazole[1,2-a]pyridine-based radiotracer [18F]2 is a sensitive tool for noninvasively diagnosing myocarditis related to inflammation of the heart muscle by assessing abnormal TSPO expression.
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Enfermedades Autoinmunes/genética , Proteínas Portadoras/genética , Expresión Génica , Miocarditis/genética , Receptores de GABA-A/genética , Animales , Enfermedades Autoinmunes/diagnóstico por imagen , Enfermedades Autoinmunes/inmunología , Biomarcadores , Proteínas Portadoras/química , Proteínas Portadoras/metabolismo , Marcaje Isotópico , Masculino , Miocarditis/diagnóstico por imagen , Miocarditis/inmunología , Tomografía de Emisión de Positrones , Trazadores Radiactivos , Radiofármacos , Ratas , Receptores de GABA-A/química , Receptores de GABA-A/metabolismoRESUMEN
The neurotransmitter dopamine (DA) was covalently linked to oxazepam (OXA), a well-known positive allosteric modulator of γ-aminobutyric acid type-A (GABAA) receptor, through a carbamate linkage (4) or a succinic spacer (6). These conjugates were synthesized with the aim of improving the delivery of DA into the brain and enhancing GABAergic transmission, which may be useful for the long-term treatment of Parkinson disease (PD). Structure-based permeability properties, in vitro stability, and blood-brain barrier (BBB) permeability studies led to identify the OXA-DA carbamate conjugate 4a as the compound better combining sufficient stability and ability to cross BBB. Finally, in vivo microdialysis experiments in freely moving rats demonstrated that 4a (20 mg/kg, i.p.) significantly increases extracellular DA levels into striatum, with a peak (more than 15-fold increase over the baseline) at about 80 min after a single administration. The stability and delivery data proved that 4a may be a promising candidate for further pharmacological studies in animal models of PD.
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Cuerpo Estriado/metabolismo , Dopamina/administración & dosificación , Dopamina/química , Oxazepam/química , Animales , Barrera Hematoencefálica/metabolismo , Cromatografía Líquida de Alta Presión , Espectroscopía de Resonancia Magnética , Masculino , Enfermedad de Parkinson/metabolismo , Ratas , Ratas Wistar , Ácido gamma-Aminobutírico/metabolismoRESUMEN
Decades of study on the role of mitochondria in living cells have evidenced the importance of the 18 kDa mitochondrial translocator protein (TSPO), first discovered in the 1977 as an alternative binding site for the benzodiazepine diazepam in the kidneys. This protein participates in a variety of cellular functions, including cholesterol transport, steroid hormone synthesis, mitochondrial respiration, permeability transition pore opening, apoptosis, and cell proliferation. Thus, TSPO has become an extremely attractive subcellular target for the early detection of disease states that involve the overexpression of this protein and the selective mitochondrial drug delivery. This special issue was programmed with the aim of summarizing the latest findings about the role of TSPO in eukaryotic cells and as a potential subcellular target of diagnostics or therapeutics. A total of 9 papers have been accepted for publication in this issue, in particular, 2 reviews and 7 primary data manuscripts, overall describing the main advances in this field.
Asunto(s)
Receptores de GABA-A/metabolismo , Animales , Diazepam/farmacología , Humanos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Receptores de GABA-A/química , Receptores de GABA-A/genéticaRESUMEN
PURPOSE: Chitosan microparticles containing celecoxib (CB), were developed as chemoprevention of bladder cancer. Furthermore two inclusion complexes of CB with methyl-ß-cyclodextrin (C1 and C2) were prepared to improve the solubility of the drug. METHODS: C1 and C2 were obtained by freeze-drying and characterized in the solid state and in solution. Microparticles loaded with CB or C1 or C2 were prepared by spray drying and fully characterized. RESULTS: The yield and encapsulation efficiencies of microparticles depended by both the viscosity and the presence of the inclusion complex in the feed medium nebulised. Generally, the microparticles exhibited a spherical shape with mean diameter of approximately 2 µm which was compatible with local intravesical administration using a catheter. The CB release studies from the microparticles allowed us to identify both immediate release systems (microparticles including the complexes) and prolonged release systems (microparticles including CB alone). The latter exhibited good adhesion to the bladder mucosa, as highlighted by a mucoadhesion study. Histological studies revealed a desquamation of the superficial cells when the bladder mucosa was treated with microparticles loaded with CB, while the morphology of the urothelium did not change when it was treated with microparticles loaded with the inclusion complex. CONCLUSION: A new CB intravesical formulation than can easily be administered with a catheter and is able to release the drug at the target site for several hours was realized. This new delivery system could be a good alternative to classic oral CB administration.