RESUMEN
The present study investigates the utilization of a supramolecular deep eutectic solvent (SUPRADES), consisting of sulfated-ß-cyclodextrin (S-ß-CD) and citric acid (CA), as a chiral selector (CS) in capillary electrophoresis for the enantiomeric separation of nefopam (NEF) and five cathinone derivatives (3-methylmethcathinone [3-MMC], 4-methylmethcathinone [4-MMC], 3,4-dimethylmethcathinone [3,4-DMMC], 4-methylethcathinone [4-MEC], and 3,4-methylendioxycathinone [MDMC]). A significant improvement in enantiomeric separation of the target analytes was observed upon the addition of S-ß-CD-CA to the background electrolyte (BGE), leading to a baseline separation of all analytes. In particular, the optimum percentage of S-ß-CD-CA, added to the BGE, was determined to be 0.075% v/v for NEF (Rs = 1.5) and 0.050% v/v for three out of five cathinone derivatives (Rs = 1.5, 1.6, and 2.4 for 3-MMC, 4-MEC, and 3,4-DMMC, respectively). In the case of 4-MMC and MDMC, a higher percentage of the CS, equal to 0.075% and 0.10% v/v, respectively, was required to achieve baseline separation (Rs = 1.5, 1.9 for MDMC and 4-MMC, respectively). The outcomes of the present study highlight the potential effectiveness of using SUPRADES as a CS in electrophoretic enantioseparations.
Asunto(s)
Alcaloides , Electroforesis Capilar , Nefopam , Electroforesis Capilar/métodos , Estereoisomerismo , Alcaloides/química , Alcaloides/análisis , Alcaloides/aislamiento & purificación , Nefopam/química , Nefopam/análisis , Nefopam/aislamiento & purificación , beta-Ciclodextrinas/química , Solventes/química , Ácido Cítrico/química , Reproducibilidad de los ResultadosRESUMEN
In this study, an optimized environmentally friendly procedure was employed to enhance the sustainable utilization of phenolic antioxidants derived from aloe vera rind by-products. The procedure involved the application of ultrasound-assisted extraction (UAE) in combination with deep eutectic solvents (DESs). Eleven different DESs and three conventional solvents were employed as extraction media for polyphenolic compounds. Choline chloride-citric acid (ChCl-CA) was selected as the most suitable extractant, considering its extraction efficiency in relation to the total phenolic content. The operating conditions of UAE were optimized and modeled by the use of response surface methodology in order to maximize the yield of total phenolics and antioxidant capacity. The optimal operational parameters for the UAE procedure were determined to be 16.5 min, 74% (v/v) DES in water, and a solvent-to-solid ratio equal to 192. HPLC analysis, which was performed on the optimum extract, revealed significant levels of phenolics present in the aloe rind. Efficient recovery of the extracted antioxidants was obtained by the use of solid-phase extraction (SPE) and polyamide cartridges. The ChCl-CA DES exhibited excellent recycling capability with a yield of over 90% through SPE. Finally, the greenness of the method was evaluated using the green AGREE and AGREEprep metrics. The results highlighted the sustainability and the greenness of the proposed extraction procedure for the aloe by-product.
RESUMEN
In this study, a novel supramolecular deep eutectic solvent consisting of sulfated-ß-CD and citric acid (S-ß-CD-CA) is reported for the first time. This innovative system was evaluated as a sole chiral selector in capillary electrophoresis for the enantioseparation of six fluorine-substituted amphetamine analogs, yielding remarkable outcomes. Baseline separations of all amphetamine analogs under study were achieved in less than 21.00 min using the S-ß-CD-CA as the chiral selector. It was observed that the addition of 0.050 % v/v S-ß-CD-CA into the background electrolyte resulted in the baseline separation of five out of the six fluorine-substituted amphetamine analogs, while in the case of the para-substituted amphetamine analog, 4-fluoramphetamine (4-FA), a higher percentage (0.15 % v/v) was required to achieve baseline enantioseparation. These findings emphasized the potential of this new supramolecular system in providing a class of solvents with promising chiral recognition properties.
Asunto(s)
beta-Ciclodextrinas , Anfetamina , Disolventes Eutécticos Profundos , Flúor , Solventes , Electroforesis Capilar/métodos , Sulfatos , EstereoisomerismoRESUMEN
A comprehensive study was performed to determine an optimum enantioseparation method for fluorine-substituted amphetamine and cathinone derivatives (fluor-amphetamine and fluor-cathinone derivatives), using a binary system consisting of carboxymethyl-ß-CD (CM-ß-CD) and a deep eutectic solvent (DES), namely choline chloride-ethylene glycol (ChCl-EG). Under this framework, the optimization and modeling of the separation conditions in a binary system were performed with the objective of maximizing resolution and minimizing analysis time. This was achieved through the application of response surface methodology. In particular, the effect of chiral selector concentration and percentage of DES on resolution and analysis time were investigated and optimized using a complete experimental design. The optimum enantioseparation conditions were determined to be 13.84 mM CM-ß-CD and 0.15% v/v ChCl-EG for fluorine-substituted amphetamine derivatives and 14.36 mM and 0.75% v/v ChCl-EG for fluorine-substituted cathinone derivatives, respectively. This combination resulted in a baseline separation for eight out of the nine analytes studied. Overall, the results demonstrated the synergistic effect of the CM-ß-CD/DES dual system and highlighted the significance of DESs as additives in capillary electrophoresis.
Asunto(s)
Disolventes Eutécticos Profundos , Flúor , Electroforesis Capilar/métodos , Colina , Anfetaminas , EstereoisomerismoRESUMEN
The objective of this study was to develop an occupation-centered and client-centered assessment tool for refugees and asylum seekers. A preliminary tool outline was produced based on a literature review, while considering previous published tools' strengths and limitations. A qualitative study was undertaken via focus groups to improve on the tool's design and adequacy for its purpose, resulting in the creation of a pilot version of the tool. Convenience sampling included 8 Greek and Cypriot professional and student occupational therapists with experience in the field, 8 international expert occupational therapists, 4 laypeople, 4 humanitarian professionals, and 5 refugees and asylum seekers. Basic qualitative content and thematic analysis led to topics regarding tool modifications that concerned categorization, formation/structure, wording, administration, and assessment scale. Corresponding tool revisions ensued. This study led to the development of the pilot version of the Refugees and Asylum Seekers Occupational Satisfaction (RASOS), which can also be used to identify underlying personal and environmental factors that contribute to self-perceived low satisfaction. A future quantitative study is required to establish the psychometric properties of the tool.
Asunto(s)
Refugiados , Humanos , Accesibilidad a los Servicios de Salud , Investigación Cualitativa , Grupos Focales , Terapeutas OcupacionalesRESUMEN
The effect of the combined use of amino acid-based ionic liquids (AAILs) and deep eutectic solvents (DESs) with either cyclodextrin- (CD) or cyclofructan- (CF) based chiral selectors for the chiral separation of amphetamine derivatives was investigated in the present study. A non-significant improvement in enantiomeric separation of target analytes was observed when AAILs were combined with either CF or CD. On the other side, a markedly improved chiral separation of enantiomers was obtained using the dual carboxymethyl-ß-cyclodextrin/DES system, highlighting the existence of a synergistic effect. After the addition of 0.5% v/v of choline chloride-ethylene glycol, the resolution of the enantiomers of amphetamine, methamphetamine and 3-fluorethamphetamine, increased from 1.4, 1.1, 1.0 to 1.8, 1.8, and 1.5 min, and the analysis times increased from 19.54, 20.48, 18.71 to 35.71, 35.78 and 32.90 min, respectively. This was not the case for the CF/DES dual system, in which the separation of amphetamines worsened, indicating an antagonistic effect. In conclusion, DESs are a very promising additive in capillary electrophoresis that can improve the separation of chiral molecules in combination with CDs but not CFs.
Asunto(s)
Ciclodextrinas , Líquidos Iónicos , Aminoácidos , Disolventes Eutécticos Profundos , Electroforesis Capilar/métodos , Estereoisomerismo , AnfetaminaRESUMEN
In recent years, carob and its derived products have gained wide attention due to their health-promoting effects, which are mainly attributed to their phenolic compounds. Carob samples (carob pulps, powders, and syrups) were analyzed to investigate their phenolic profile using high-performance liquid chromatography (HPLC), with gallic acid and rutin being the most abundant compounds. Moreover, the antioxidant capacity and total phenolic content of the samples were estimated through DPPH (IC50 98.83-488.47 mg extract/mL), FRAP (48.58-144.32 µmol TE/g product), and Folin-Ciocalteu (7.20-23.18 mg GAE/g product) spectrophotometric assays. The effect of thermal treatment and geographical origin of carobs and carob-derived products on their phenolic composition was assessed. Both factors significantly affect the concentrations of secondary metabolites and, therefore, samples' antioxidant activity (p-value < 10-7). The obtained results (antioxidant activity and phenolic profile) were evaluated via chemometrics, through a preliminary principal component analysis (PCA) and orthogonal partial least square-discriminant analysis (OPLS-DA). The OPLS-DA model performed satisfactorily, differentiating all samples according to their matrix. Our results indicate that polyphenols and antioxidant capacity can be chemical markers for the classification of carob and its derived products.
Asunto(s)
Antioxidantes , Fabaceae , Antioxidantes/química , Flavonoides/química , Quimiometría , Fenoles/química , Fabaceae/químicaRESUMEN
During this study, a simple and easy-to-prepare electrophoretic method was developed for the enantioseparation of amphetamine and cathinone derivatives. Different types of ß-cyclodextrin and cyclofructan-based chiral selectors (CSs), both native and derivatized, were utilized, and the most effective ones, in terms of resolution and analysis time, were identified. In addition, several electrophoretic parameters, such as background electrolyte concentration and pH, and CS concentration, were examined to optimize the separation conditions. Under the optimal electrophoretic conditions, 10 psychoactive substances were enantiomerically separated using 1 mM sulfated cyclofructan-6 (SCF-6) for the amphetamine derivatives and 1 mM sulfated cyclofructan-7 (SCF-7) for the cathinone derivatives dissolved in an aqueous solution of 20-mM monobasic sodium phosphate at pH 2.5, a temperature of 25°C, and an applied voltage of 25 kV. In addition, the method was validated by estimating the intra- and interday precision.
Asunto(s)
Ciclodextrinas , Ciclodextrinas/química , Estereoisomerismo , Electroforesis Capilar/métodos , Anfetamina , SulfatosRESUMEN
An ultrasound-assisted method was used for the extraction of phenolics from defatted black cumin seeds (Nigella sativa L.), and the effects of several extraction factors on the total phenolic content and DPPH radical scavenging activity were investigated. To improve the extraction efficiency of phenolics from black cumin seed by ultrasonic-assisted extraction, the optimal extraction conditions were determined as follows: ethanol concentration of 59.1%, extraction temperature of 44.6 °C and extraction time of 32.5 min. Under these conditions, the total phenolic content and DPPH radical scavenging activity increased by about 70% and 38%, respectively, compared with conventional extraction. Furthermore, a complementary quantitative analysis of individual phenolic compounds was carried out using the HPLC-UV technique. The phenolic composition revealed high amounts of epicatechin (1.88-2.37 mg/g) and rutin (0.96-1.21 mg/g) in the black cumin seed extracts. Ultrasonic-assisted extraction can be a useful extraction method for the recovery of polyphenols from defatted black cumin seeds.
Asunto(s)
Catequina , Cuminum , Nigella sativa , Antioxidantes/farmacología , Catequina/análisis , Etanol , Nigella sativa/química , Fenoles/química , Extractos Vegetales/farmacología , Polifenoles/análisis , Rutina/análisis , Semillas/químicaRESUMEN
Haematopoietic stem cells (HSCs) arise in the embryo from the arterial endothelium through a process known as the endothelial-to-haematopoietic transition (EHT)1-4. This process generates hundreds of blood progenitors, of which a fraction go on to become definitive HSCs. It is generally thought that most adult blood is derived from those HSCs, but to what extent other progenitors contribute to adult haematopoiesis is not known. Here we use in situ barcoding and classical fate mapping to assess the developmental and clonal origins of adult blood in mice. Our analysis uncovers an early wave of progenitor specification-independent of traditional HSCs-that begins soon after EHT. These embryonic multipotent progenitors (eMPPs) predominantly drive haematopoiesis in the young adult, have a decreasing yet lifelong contribution over time and are the predominant source of lymphoid output. Putative eMPPs are specified within intra-arterial haematopoietic clusters and represent one fate of the earliest haematopoietic progenitors. Altogether, our results reveal functional heterogeneity during the definitive wave that leads to distinct sources of adult blood.
Asunto(s)
Envejecimiento , Linaje de la Célula , Embrión de Mamíferos , Hematopoyesis , Células Madre Hematopoyéticas , Animales , Embrión de Mamíferos/citología , Células Madre Hematopoyéticas/citología , Ratones , Células Madre Multipotentes/citologíaRESUMEN
In this study, cyclofructan (CF)-, cyclodextrin (CD)-, and polysaccharide-based chiral stationary phases (CSPs) were exploited in high-performance liquid chromatography (HPLC) for the chiral separations of different clinically and pharmaceutically important compounds. In particular, R-naphthylethyl carbamate CF6 (RN-CF6), 3,5-dimethylphenyl carbamate CF7 (DMP-CF7), neutral beta cyclodextrin (ß-CD), 3,5-dimethylphenyl carbamate ß-CD (DMP-ß-CD), and cellulose tris-(3,5-dimethylphenylcarbamate) (Cellulose-Tris DMP) columns were utilized under isocratic elution. The performance of these CSPs as chiral separation media was evaluated by use of nine analytes: acidic, basic, and amphiprotic. A possible correlation between the functional groups of these analytes and the chiral-recognition ability of each chiral column was also examined. The enantioseparations were optimized by varying different parameters, such as mobile phase additives, column temperature, and flow rate. Finally, a comparison was made between all CSPs, and it was expressed in terms of resolution (RS), efficiency (N), selectivity (α), retention factors (k1', k2') and analysis time (tR1, tR2). It was observed that RN-CF6 was the most suitable and efficient CSP for the chiral separation of various types of analytes, including acids, primary and tertiary amines, alcohols, and many neutral compounds. It was the only CSP that provided baseline enantioseparation of thyroxine (RS = 1.6) and cetirizine (RS = 2.0).
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Ciclodextrinas/química , Fructanos/química , Preparaciones Farmacéuticas/aislamiento & purificación , Polisacáridos/química , EstereoisomerismoRESUMEN
Extracts derived from the Ceratonia siliqua L. (carob) tree have been widely studied for their ability to prevent many diseases mainly due to the presence of polyphenolic compounds. In this study, we explored, for the first time, the anti-cancer properties of Cypriot carobs. We produced extracts from ripe and unripe whole carobs, pulp and seeds using solvents with different polarities. We measured the ability of the extracts to inhibit proliferation and induce apoptosis in cancer and normal immortalized breast cells, using the MTT assay, cell cycle analysis and Western Blotting. The extracts' total polyphenol content and anti-oxidant action was evaluated using the Folin-Ciocalteu method and the DPPH assay. Finally, we used LC-MS analysis to identify and quantify polyphenols in the most effective extracts. Our results demonstrate that the anti-proliferative capacity of carob extracts varied with the stage of carob maturity and the extraction solvent. The Diethyl-ether and Ethyl acetate extracts derived from the ripe whole fruit had high Myricetin content and also displayed specific activity against cancer cells. Their mechanism of action involved caspase-dependent and independent apoptosis. Our results indicate that extracts from Cypriot carobs may have potential uses in the development of nutritional supplements and pharmaceuticals.
Asunto(s)
Antineoplásicos/química , Antineoplásicos/farmacología , Fabaceae/química , Fenoles/química , Fenoles/farmacología , Solventes/química , Apoptosis/efectos de los fármacos , Caspasas/metabolismo , Línea Celular Tumoral , Frutas/química , Humanos , Semillas/químicaRESUMEN
In this work, a simple, reliable, and fast capillary electrophoretic method was developed and validated for the simultaneous determination of 12 polyphenolic compounds, the most frequently found in carob's pulp and seeds. The present work deals with the development of a novel dual electrophoretic system based on the combined use of ß-CD and ionic liquid (IL) as buffer additives. A baseline separation of the target analytes was achieved in less than 10 min by using a BGE consisting of 35 mM borate along with 15 mM ß-CD and 3 mM l-alanine tert butyl ester lactate (l-AlaC4 Lac) IL as buffer additives at pH 9.5, a temperature of 25°C, and an applied voltage of 30 kV. The application of the developed electrophoretic method to real samples enabled the identification and quantification of the main phenolic constituents of both ripe and unripe carob pulp extracts. The results revealed the predominance of gallic acid in both ripe (183.92 µg/g carob pulp) and unripe (205.10 µg/g carob pulp) carob pulp and highlighted the great influence of the ripening stage on carobs polyphenolic composition, with unripe pods being more enriched in polyphenols (total phenolics detected: 912.58 and 283.13 µg/g unripe and ripe carob pulp).
Asunto(s)
Fabaceae , Líquidos Iónicos , Fenoles , beta-Ciclodextrinas , Electrólitos , Galactanos , Mananos , Gomas de PlantasRESUMEN
Polyphenols in carobs have recently attracted great attention due to their wide range of biological and health promoting effects. A comprehensive study was conducted to find an optimum method for the extraction, purification and characterization of these valuable bioactive substances. Under this framework, the ultrasound-assisted extraction (UAE) of polyphenols from carob pulp was optimized by the maximization of the yield in total phenolics using response surface methodology. In particular, the effects of solid-solvent ratio, solvent concentration, extraction time, sonication amplitude, and sonication mode were investigated and optimized using a complete experimental design. In comparison to conventional extraction techniques, UAE offered a higher yield of antioxidants and a shorter processing time. Solid-phase extraction was evaluated as a clean-up strategy prior to the electrophoretic analysis of extracts. The results from the analysis of real samples revealed the predominance of gallic acid and highlighted the great influence of the ripening stage on carobs composition.
Asunto(s)
Antioxidantes/química , Antioxidantes/aislamiento & purificación , Fraccionamiento Químico/métodos , Galactanos/química , Mananos/química , Gomas de Plantas/química , Polifenoles/análisis , Ondas Ultrasónicas , Solventes/químicaRESUMEN
Cannabis is by far the most widely abused illicit drug globe wide. The analysis of its main psychoactive components in conventional and non-conventional biological matrices has recently gained a great attention in forensic toxicology. Literature states that its abuse causes neurocognitive impairment in the domains of attention and memory, possible macrostructural brain alterations and abnormalities of neural functioning. This suggests the necessity for the development of a sensitive and a reliable analytical method for the detection and quantification of cannabinoids in human biological specimens. In this review, we focus on a number of analytical methods that have, so far, been developed and validated, with particular attention to the new "golden standard" method of forensic analysis, liquid chromatography mass spectrometry or tandem mass spectrometry. In addition, this review provides an overview of the effective and selective methods used for the extraction and isolation of cannabinoids from (i) conventional matrices, such as blood, urine and oral fluid and (ii) alternative biological matrices, such as hair, cerumen and meconium.
Asunto(s)
Cannabinoides/análisis , Cromatografía Liquida/métodos , Espectrometría de Masas , Detección de Abuso de Sustancias/métodos , Líquidos Corporales/química , Cannabinoides/aislamiento & purificación , Toxicología Forense/métodos , Cabello/química , Humanos , Espectrometría de Masas en TándemRESUMEN
In this study, cerumen, a non-conventional biological secretion, was examined as an alternative matrix for forensic analyzis. A fully validated analytical UPLC-MS/MS method was developed for the detection and quantification of the most prevalent psychoactive illicit drug globe wide, Δ9-tethrahydrocannabinol, commonly known as THC, and four major cannabinoids found in cannabis Sativa. The method was validated, and standard external calibration curves were established with correlation coefficients > 0.99. A validated experimental procedure, along with a direct extraction of cannabinoids with acidified acetonitrile resulted in a short total analyzis time and a good extraction efficiency for all the analytes under study. LOD and LOQ values were determined to be 0.01-0.08 pg/mg and 0.04-0.23 pg/mg, respectively. To prove applicability of the proposed assay, volunteers were selected, and cerumen samples were examined for cannabis. The analyzis by use of UPLC-MS/MS indicated that all samples were positive, reporting recent cannabis abuse. Surprisingly, both THC and Cannabinol (CBN) were detected, and quantification was possible in 75% of the cases.
Asunto(s)
Cannabinoides/análisis , Cerumen/química , Espectrometría de Masas en Tándem/métodos , Calibración , Cannabinoides/química , Cannabis/química , Cromatografía Líquida de Alta Presión , Humanos , Límite de Detección , Reproducibilidad de los ResultadosRESUMEN
The exact localization of hematopoietic stem cells (HSCs) in their native bone marrow (BM) microenvironment remains controversial, because multiple cell types have been reported to physically associate with HSCs. In this study, we comprehensively quantified HSC localization with up to 4 simultaneous (9 total) BM components in 152 full-bone sections from different bone types and 3 HSC reporter lines. We found adult femoral α-catulin-GFP+ or Mds1GFP/+Flt3Cre HSCs proximal to sinusoids, Cxcl12 stroma, megakaryocytes, and different combinations of those populations, but not proximal to bone, adipocyte, periarteriolar, or Schwann cells. Despite microanatomical differences in femurs and sterna, their adult α-catulin-GFP+ HSCs had similar distributions. Importantly, their microenvironmental localizations were not different from those of random dots, reflecting the relative abundance of imaged BM populations rather than active enrichment. Despite their functional heterogeneity, dormant label-retaining (LR) and non-LR hematopoietic stem and progenitor cells both had indistinguishable localization from α-catulin-GFP+ HSCs. In contrast, cycling juvenile BM HSCs preferentially located close to Cxcl12 stroma and farther from sinusoids/megakaryocytes. We expect our study to help resolve existing confusion regarding the exact localization of different HSC types, their physical association with described BM populations, and their tissue-wide combinations.
Asunto(s)
Células Madre Adultas/citología , Células Madre Hematopoyéticas/citología , Nicho de Células Madre , Animales , RatonesRESUMEN
Multipotent Nkx2-1-positive lung epithelial primordial progenitors of the foregut endoderm are thought to be the developmental precursors to all adult lung epithelial lineages. However, little is known about the global transcriptomic programs or gene networks that regulate these gateway progenitors in vivo. Here we use bulk RNA-sequencing to describe the unique genetic program of in vivo murine lung primordial progenitors and computationally identify signaling pathways, such as Wnt and Tgf-ß superfamily pathways, that are involved in their cell-fate determination from pre-specified embryonic foregut. We integrate this information in computational models to generate in vitro engineered lung primordial progenitors from mouse pluripotent stem cells, improving the fidelity of the resulting cells through unbiased, easy-to-interpret similarity scores and modulation of cell culture conditions, including substratum elastic modulus and extracellular matrix composition. The methodology proposed here can have wide applicability to the in vitro derivation of bona fide tissue progenitors of all germ layers.
Asunto(s)
Células Epiteliales/citología , Pulmón/citología , Ratones/genética , Células Madre Pluripotentes/citología , Animales , Técnicas de Cultivo de Célula , Diferenciación Celular , Células Epiteliales/metabolismo , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Femenino , Estratos Germinativos/embriología , Estratos Germinativos/metabolismo , Pulmón/embriología , Pulmón/metabolismo , Masculino , Ratones/embriología , Ratones/metabolismo , Ratones Endogámicos C57BL , Ratones Transgénicos , Células Madre Pluripotentes/metabolismo , Transducción de Señal , Factor Nuclear Tiroideo 1/genética , Factor Nuclear Tiroideo 1/metabolismo , Transcriptoma , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
The biology of haematopoietic stem cells (HSCs) has predominantly been studied under transplantation conditions1,2. It has been particularly challenging to study dynamic HSC behaviour, given that the visualization of HSCs in the native niche in live animals has not, to our knowledge, been achieved. Here we describe a dual genetic strategy in mice that restricts reporter labelling to a subset of the most quiescent long-term HSCs (LT-HSCs) and that is compatible with current intravital imaging approaches in the calvarial bone marrow3-5. We show that this subset of LT-HSCs resides close to both sinusoidal blood vessels and the endosteal surface. By contrast, multipotent progenitor cells (MPPs) show greater variation in distance from the endosteum and are more likely to be associated with transition zone vessels. LT-HSCs are not found in bone marrow niches with the deepest hypoxia and instead are found in hypoxic environments similar to those of MPPs. In vivo time-lapse imaging revealed that LT-HSCs at steady-state show limited motility. Activated LT-HSCs show heterogeneous responses, with some cells becoming highly motile and a fraction of HSCs expanding clonally within spatially restricted domains. These domains have defined characteristics, as HSC expansion is found almost exclusively in a subset of bone marrow cavities with bone-remodelling activity. By contrast, cavities with low bone-resorbing activity do not harbour expanding HSCs. These findings point to previously unknown heterogeneity within the bone marrow microenvironment, imposed by the stages of bone turnover. Our approach enables the direct visualization of HSC behaviours and dissection of heterogeneity in HSC niches.
Asunto(s)
Células Madre Hematopoyéticas/metabolismo , Imagen Molecular , Animales , Remodelación Ósea , Movimiento Celular , Proliferación Celular , Supervivencia Celular , Femenino , Genes Reporteros , Hipoxia/metabolismo , Proteína del Locus del Complejo MDS1 y EV11/genética , Proteína del Locus del Complejo MDS1 y EV11/metabolismo , Masculino , Ratones , Oxígeno/metabolismo , Cráneo/citología , Tirosina Quinasa 3 Similar a fms/genética , Tirosina Quinasa 3 Similar a fms/metabolismoRESUMEN
The combined use of chiral ionic liquids (CILs) and conventional chiral selectors (CSs) in CE, to establish a synergistic system, has proven to be an effective approach for the separation of enantiomeric pairs. In this study, a new CE method was developed, employing a binary system of a CS, either a cyclodextrin (CD) or a cyclofructan (CF), and a chiral amino acid ester-based ionic liquid (AAIL), for the chiral separation of four basic, acidic and zwitterionic drug compounds. In particular, the enantioseparation of two anticoagulants, warfarin (WAR) and coumachlor (COU), a non-opioid analgesic, nefopam (NEF) and a third-generation antihistamine, fexofenadine (FXD), was examined, by supporting the BGE with a CS and the chiral AAIL L-alanine tert butyl ester lactate (L-AlaC4 Lac). Parameters, such as the type of the CS, the concentration of both the CS and L-AlaC4 Lac, and the BGE pH, were methodically examined in order to optimize the chiral separation of each analyte. It was observed that, in some cases, the addition of the AAIL into the BGE improved both resolution (Rs ) and efficiency (N) significantly. In other cases, the synergistic effect enabled baseline separation of analyte enantiomers, at a much lower concentration of the CS. Finally, after optimization of separation conditions, baseline separations (Rs >1.5) of all four analytes were achieved in less than 5 min.