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1.
Eur Psychiatry ; 66(1): e17, 2023 01 24.
Artículo en Inglés | MEDLINE | ID: mdl-36691786

RESUMEN

BACKGROUND: Reported childhood adversity (CA) is associated with development of depression in adulthood and predicts a more severe course of illness. Although elevated serotonin 1A receptor (5-HT1AR) binding potential, especially in the raphe nuclei, has been shown to be a trait associated with major depression, we did not replicate this finding in an independent sample using the partial agonist positron emission tomography tracer [11C]CUMI-101. Evidence suggests that CA can induce long-lasting changes in expression of 5-HT1AR, and thus, a history of CA may explain the disparate findings. METHODS: Following up on our initial report, 28 unmedicated participants in a current depressive episode (bipolar n = 16, unipolar n = 12) and 19 non-depressed healthy volunteers (HVs) underwent [11C]CUMI-101 imaging to quantify 5-HT1AR binding potential. Participants in a depressive episode were stratified into mild/moderate and severe CA groups via the Childhood Trauma Questionnaire. We hypothesized higher hippocampal and raphe nuclei 5-HT1AR with severe CA compared with mild/moderate CA and HVs. RESULTS: There was a group-by-region effect (p = 0.011) when considering HV, depressive episode mild/moderate CA, and depressive episode severe CA groups, driven by significantly higher hippocampal 5-HT1AR binding potential in participants in a depressive episode with severe CA relative to HVs (p = 0.019). Contrary to our hypothesis, no significant binding potential differences were detected in the raphe nuclei (p-values > 0.05). CONCLUSIONS: With replication in larger samples, elevated hippocampal 5-HT1AR binding potential may serve as a promising biomarker through which to investigate the neurobiological link between CA and depression.


Asunto(s)
Experiencias Adversas de la Infancia , Receptor de Serotonina 5-HT1A , Humanos , Receptor de Serotonina 5-HT1A/metabolismo , Depresión/diagnóstico por imagen , Depresión/metabolismo , Serotonina/metabolismo , Tomografía de Emisión de Positrones/métodos , Hipocampo/diagnóstico por imagen , Encéfalo/metabolismo
2.
J Child Adolesc Trauma ; 15(4): 1105-1112, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36439668

RESUMEN

Evidence suggests that adults with a history of childhood maltreatment, the experience of emotional or physical neglect and/or abuse within the family during childhood, have blunted reward and stress processing, and higher risk of depression. The mu opioid receptor rich nucleus accumbens and amygdala are critical to reward and stress processing respectively. We hypothesized that nucleus accumbens and amygdala mu opioid receptor densities and activity (change in receptor binding due to endogenous opioid release or receptor conformation change) were negatively associated with childhood maltreatment in healthy young adults. Maltreatment was assessed with the Childhood Trauma Questionnaire (CTQ). Healthy participants, n = 75 (52% female) completed [11C]carfentanil positron emission tomography imaging labeling mu opioid receptors. The relationship between CTQ score and binding potential (BPND, proportional to density of unoccupied receptors) was evaluated with a linear mixed effects model. No significant relationship was found between CTQ score and BPND (f = 3.28; df = 1, 73; p = 0.074) or change in BPND (activity) (t = 1.48; df = 198.3; p = 0.14). This is the first investigation of mu opioid receptors in those with childhood maltreatment. We did not identify a significant relationship between mu opioid receptor dynamics and severity of maltreatment in those without psychopathology. Because this cohort has a low CTQ score average, this may indicate that those with low severity of maltreatment may not have associated changes in mu opioid receptor dynamics. Future directions include evaluating a cohort with increased severity of childhood maltreatment.

3.
Anal Chim Acta ; 1233: 340506, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-36283785

RESUMEN

Sebum from sebaceous glands is a rich source of volatile organic compounds (VOCs) that can readily be sampled non-invasively from the surface of skin. The VOC profiles of sebum can then be used to obtain information regarding different medical conditions including diabetes and Parkinson's Disease. However, the effects of sampling approaches and environmental factors on sebum VOC profiles are not established and the confident attribution of VOCs to disease states needs to be free of extraneous influences such as sampling materials and preparatory conditions. Here, we investigated a more standardised skin swab sampling approach for profiling sebum VOCs from healthy human subjects using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Using a standard GC-MS method for the chemical analysis of sebum swabs, a surprisingly high number of VOCs originate from 'blank' medical swab material alone (up to 74 VOCs) and from the ambient environment (up to 29 VOCs) based on control experiments. We found that heat-treatment of medical swabs prior to GC-MS reduced the number of VOCs detected from 'blank' swabs and improved the reproducibility of VOC profiling, however significant VOC absorption can still occur from environmental exposure to ambient air. VOCs identified in 'blank' swabs consisted predominantly of hydrocarbons, esters, and silicon-based compounds and depended strongly on the material used (cotton and polyester-rayon). Environmental VOCs found to absorb to swabs from the ambient air during sampling included 1-butylheptyl-benzene and hexadecanoic acid methyl ester as well as exogenous VOCs such as isopropyl palmitate and isopropyl myristate. In contrast, sebum VOCs consisted primarily of esters, alcohols, ketones, and aldehydes. 23 and 18 VOCs were identified in sebum collected using polyester-rayon and cotton-based medical swabs, respectively, with 14 VOCs common to both swabs. The effect of subject bathing prior to sebum sampling had minimal impact on the VOC profiles. However, individual differences owing to external factors such as skin type, diet, and exercise will likely influence sebum production. This study highlights the importance of using rigorous controls in sebum sampling, and recommendations are provided for future research involving sebum VOC analysis. For example, the use of sebum sample replicates across multiple days, and the use of control swabs during sample collection is required to confirm the origin and reliability of sebum VOCs. It is anticipated that these recommendations in conjunction with a library of well-established VOCs from medical swabs will further strengthen biomarker identification resulting from sebum VOC analysis.


Asunto(s)
Contaminantes Atmosféricos , Compuestos Orgánicos Volátiles , Humanos , Compuestos Orgánicos Volátiles/análisis , Contaminantes Atmosféricos/análisis , Reproducibilidad de los Resultados , Benceno , Monitoreo del Ambiente/métodos , Sebo/química , Ácido Palmítico , Silicio , Cromatografía de Gases y Espectrometría de Masas , Hidrocarburos , Aldehídos/análisis , Biomarcadores/análisis , Ésteres/análisis , Cetonas/análisis , Poliésteres
4.
Mol Psychiatry ; 27(9): 3833-3841, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35982258

RESUMEN

Previous proton magnetic resonance spectroscopy (1H-MRS) studies suggest a perturbation in glutamate and/or GABA in Major Depressive Disorder (MDD). However, no studies examine the ratio of glutamate and glutamine (Glx) to GABA (Glx/GABA) as it relates to depressive symptoms, which may be more sensitive than either single metabolite. Using a within-subject design, we hypothesized that reduction in depressive symptoms correlates with reduction in Glx/GABA in the anterior cingulate cortex (ACC). The present trial is a randomized clinical trial that utilized 1H-MRS to examine Glx/GABA before and after 8 weeks of escitalopram or placebo. Participants completed the 17-item Hamilton Depression Rating Scale (HDRS17) and underwent magnetic resonance spectroscopy before and after treatment. Two GABA-edited MEGA-PRESS acquisitions were interleaved with a water unsuppressed reference scan. GABA and Glx were quantified from the average difference spectrum, with preprocessing using Gannet and spectral fitting using TARQUIN. Linear mixed models were utilized to evaluate relationships between change in HDRS17 and change in Glx/GABA using a univariate linear regression model, multiple linear regression incorporating treatment type as a covariate, and Bayes Factor (BF) hypothesis testing to examine strength of evidence. No significant relationship was detected between percent change in Glx, GABA, or Glx/GABA and percent change in HDRS17, regardless of treatment type. Further, MDD severity before/after treatment did not correlate with ACC Glx/GABA. In light of variable findings in the literature and lack of association in our investigation, future directions should include evaluating glutamate and glutamine individually to shed light on the underpinnings of MDD severity. Advancing Personalized Antidepressant Treatment Using PET/MRI, ClinicalTrials.gov, NCT02623205.


Asunto(s)
Trastorno Depresivo Mayor , Ácido Glutámico , Humanos , Ácido Glutámico/metabolismo , Glutamina/metabolismo , Trastorno Depresivo Mayor/tratamiento farmacológico , Trastorno Depresivo Mayor/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Teorema de Bayes , Depresión/tratamiento farmacológico
5.
Psychiatry Res Neuroimaging ; 324: 111505, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35688046

RESUMEN

Rejection sensitivity (RS) is the heightened expectation or perception of social rejection and is a feature of many psychiatric disorders. As endogenous opioid pathways have been implicated in response to social rejection and reward, we hypothesize that RS will be negatively associated with mu opioid receptor (MOR) baseline binding and activity during rejection and acceptance stimuli. In exploratory analyses, we assessed the relationships between MOR activity and changes in mood and self-esteem before and after stimuli. Healthy participants, N = 75 (52% female), completed rejection and acceptance tasks during [11C]carfentanil positron emission tomography (PET) scans. MOR activity in the amygdala, midline thalamus, anterior insula, and nucleus accumbens (NAc) was evaluated. RS was not related to MOR baseline binding potential or activity during acceptance or rejection tasks in any region. Increased MOR activity in the NAc was associated with increase in ratings of self-esteem and positive mood during the period between acceptance task administration and approximately 5 min after the task completion. Our results suggest that endogenous opioid response to social rejection is independent of RS in healthy individuals. MOR activity in the NAc was associated with increase self-esteem and positive mood after experiencing social feedback, warranting further investigation.


Asunto(s)
Analgésicos Opioides , Receptores Opioides mu , Retroalimentación , Femenino , Humanos , Masculino , Tomografía de Emisión de Positrones/métodos , Receptores Opioides mu/metabolismo , Recompensa
6.
ACS Chem Neurosci ; 13(7): 883-896, 2022 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-35286811

RESUMEN

The quantification of α-synuclein aggregates has emerged as a promising biomarker for synucleinopathies. Assays that amplify and detect such aggregates have revealed the presence of seeding-competent species in biosamples of patients diagnosed with Parkinson's disease. However, multiple species, such as oligomers and amyloid fibrils, are formed during the aggregation of α-synuclein; these species are likely to coexist in biological samples, and thus it remains unclear which species(s) are contributing to the signal detected in seeding assays. To identify individual contributions to the amplification process, recombinant oligomers and preformed fibrils were produced and purified to characterize their individual biochemical and seeding potential. Here, we used single molecule spectroscopy to track the formation and purification of oligomers and fibrils at the single particle level and compare their respective seeding potential in an amplification assay. Single molecule detection validates that size-exclusion chromatography efficiently separates oligomers from fibrils. Oligomers were found to be seeding-competent, but our results reveal that their seeding behavior is very different compared to that of preformed fibrils, in our amplification assay. Overall, our data suggest that even a low number of preformed fibrils present in biosamples is likely to dominate the response in seeding assays.


Asunto(s)
Enfermedad de Parkinson , alfa-Sinucleína , Amiloide , Bioensayo , Biomarcadores/análisis , Humanos , Enfermedad de Parkinson/diagnóstico , alfa-Sinucleína/química
7.
Neuroimage Clin ; 32: 102858, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34689056

RESUMEN

There is critical need for a clinically useful tool to predict antidepressant treatment outcome in major depressive disorder (MDD) to reduce suffering and mortality. This analysis sought to build upon previously reported antidepressant treatment efficacy prediction from 2-[18F]-fluorodeoxyglucose - Positron Emission Tomography (FDG-PET) using metabolic rate of glucose uptake (MRGlu) from dynamic FDG-PET imaging with the goal of translation to clinical utility. This investigation is a randomized, double-blind placebo-controlled trial. All participants were diagnosed with MDD and received an FDG-PET scan before randomization and after treatment. Hamilton Depression Rating Scale (HDRS-17) was completed in participants diagnosed with MDD before and after 8 weeks of escitalopram, or placebo. MRGlu (mg/(min*100 ml)) was estimated within the raphe nuclei, right insula, and left ventral Prefrontal Cortex in 63 individuals. Linear regression was used to examine the association between pretreatment MRGlu and percent decrease in HDRS-17. Additionally, the association between percent decrease in HDRS-17 and percent change in MRGlu between pretreatment scan and post-treatment scan was examined. Covariates were treatment type (SSRI/placebo), handedness, sex, and age. Depression severity decrease (n = 63) was not significantly associated with pretreatment MRGlu in the raphe nuclei (ß = -2.61e-03 [-0.26, 0.25], p = 0.98), right insula (ß = 0.05 [-0.23, 0.32], p = 0.72), or ventral prefrontal cortex (ß = 0.06 [-0.23, 0.34], p = 0.68) where ß is the standardized estimated coefficient, with a 95% confidence interval, or in whole brain voxelwise analysis (family-wise error correction, alpha = 0.05). MRGlu percent change was not significantly associated with depression severity decrease (n = 58) before multiple comparison correction in the RN (ß = 0.20 [-0.07, 0.47], p = 0.15), right insula (ß = 0.24 [-0.03, 0.51], p = 0.08), or vPFC (ß = 0.22 [-0.06, 0.50], p = 0.12). We propose that FDG-PET imaging does not indicate a clinically relevant biomarker of escitalopram or placebo treatment response in heterogeneous major depressive disorder cohorts. Future directions include focusing on potential biologically-based subtypes of major depressive disorder by implementing biomarker stratified designs.


Asunto(s)
Trastorno Depresivo Mayor , Antidepresivos/uso terapéutico , Encéfalo/diagnóstico por imagen , Trastorno Depresivo Mayor/diagnóstico por imagen , Trastorno Depresivo Mayor/tratamiento farmacológico , Método Doble Ciego , Escitalopram , Glucosa , Humanos , Resultado del Tratamiento
8.
Commun Biol ; 4(1): 112, 2021 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-33495510

RESUMEN

Dual Bcl-2/Bcl-xL inhibitors are expected to deliver therapeutic benefit in many haematological and solid malignancies, however, their use is limited by tolerability issues. AZD4320, a potent dual Bcl-2/Bcl-xL inhibitor, has shown good efficacy however had dose limiting cardiovascular toxicity in preclinical species, coupled with challenging physicochemical properties, which prevented its clinical development. Here, we describe the design and development of AZD0466, a drug-dendrimer conjugate, where AZD4320 is chemically conjugated to a PEGylated poly-lysine dendrimer. Mathematical modelling was employed to determine the optimal release rate of the drug from the dendrimer for maximal therapeutic index in terms of preclinical anti-tumour efficacy and cardiovascular tolerability. The optimised candidate is shown to be efficacious and better tolerated in preclinical models compared with AZD4320 alone. The AZD4320-dendrimer conjugate (AZD0466) identified, through mathematical modelling, has resulted in an improved therapeutic index and thus enabled progression of this promising dual Bcl-2/Bcl-xL inhibitor into clinical development.


Asunto(s)
Antineoplásicos , Dendrímeros , Neoplasias/tratamiento farmacológico , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapéutico , Dendrímeros/síntesis química , Dendrímeros/química , Dendrímeros/farmacocinética , Dendrímeros/uso terapéutico , Perros , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones SCID , Neoplasias/metabolismo , Neoplasias/patología , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Ratas , Ratas Wistar , Índice Terapéutico , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto , Proteína bcl-X/antagonistas & inhibidores
9.
Mol Cancer Res ; 19(3): 507-515, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33234577

RESUMEN

Hematopoietic-derived cells are integral components of the tumor microenvironment and serve as critical mediators of tumor-host interactions. Host cells derived from myeloid and lymphoid lineages perform well-established functions linked to cancer development, progression, and response to therapy. It is unclear whether host erythroid cells also contribute to shaping the path that cancer can take, but emerging evidence points to this possibility. Here, we show that tumor-promoting environmental stress and tumor-induced hemodynamic changes trigger renal erythropoietin production and erythropoietin-dependent expansion of splenic erythroid cell populations in mice. These erythroid cells display molecular features indicative of an immature erythroid phenotype, such as the expression of both CD71 and TER119 and the retention of intact nuclei, and express genes encoding immune checkpoint molecules. Nucleated erythroid cells with similar properties are present in mouse and human tumor tissues. Antibody-mediated erythropoietin blockade reduces tumor-responsive erythroid cell induction and tumor growth. These findings reveal the potential of tumor-induced erythropoietin and erythroid cells as targets for cancer treatment. IMPLICATIONS: : Our study identifies erythropoietin and erythroid cells as novel players in tumor-host interactions and highlights the involvement of multiorgan signaling events in their induction in response to environmental stress and tumor growth.


Asunto(s)
Células Eritroides/metabolismo , Proteínas de Punto de Control Inmunitario/metabolismo , Animales , Diferenciación Celular , Humanos , Ratones , Transducción de Señal
10.
Contact Dermatitis ; 84(5): 308-316, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33236775

RESUMEN

BACKGROUND: Allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD) are common skin conditions with an overlapping clinical and histological appearance, but distinct underlying mechanisms. Patch testing is the gold standard for ACD diagnosis, yet the interpretation of its results may be confounded by weak and varying macroscopic reactions. OBJECTIVE: To examine whether gene transcript profiling of RNA sampled from patch tested patient skin by tape stripping (TS) could differentiate ACD from ICD and the baseline skin state (control) METHODS: Nine patients (seven females, two males; mean age 38.6 years, range 24-72 years) with confirmed ACD through patch testing were recruited. Total RNA was isolated from TS samples and relative transcript abundance was determined by quantitative real-time polymeraise chain reaction using 39 gene-specific primers. RESULTS: TS captured gene transcripts derived from diverse skin cell types, including not only keratinocytes, but also epidermal and dermal antigen-presenting cells. Among the genes analysed in transcript profiling, genes encoding epidermal barrier components and inflammatory mediators exhibited changes in transcript abundance in ACD skin compared to ICD or control skin. CONCLUSIONS: Our findings reveal the potential of skin TS for non-invasive biopsy during patch testing and molecular marker-based ACD diagnosis.


Asunto(s)
Dermatitis Alérgica por Contacto/diagnóstico , Dermatitis Alérgica por Contacto/genética , Perfilación de la Expresión Génica/métodos , Cinta Quirúrgica , Adulto , Anciano , Dermatitis Irritante/diagnóstico , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas del Parche , Piel/metabolismo , Adulto Joven
11.
Am J Bot ; 107(8): 1165-1176, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32864740

RESUMEN

PREMISE: Within closed-canopy forests, vertical gradients of light and atmospheric CO2 drive variations in leaf carbon isotope ratios, leaf mass per area (LMA), and the micromorphology of leaf epidermal cells. Variations in traits observed in preserved or fossilized leaves could enable inferences of past forest canopy closure and leaf function and thereby habitat of individual taxa. However, as yet no calibration study has examined how isotopic, micro- and macromorphological traits, in combination, reflect position within a modern closed-canopy forest or how these could be applied to the fossil record. METHODS: Leaves were sampled from throughout the vertical profile of the tropical forest canopy using the 48.5 m crane at the Daintree Rainforest Observatory, Queensland, Australia. Carbon isotope ratios, LMA, petiole metric (i.e., petiole-width2 /leaf area, a proposed proxy for LMA that can be measured from fossil leaves), and leaf micromorphology (i.e., undulation index and cell area) were compared within species across a range of canopy positions, as quantified by leaf area index (LAI). RESULTS: Individually, cell area, δ13 C, and petiole metric all correlated with both LAI and LMA, but the use of a combined model provided significantly greater predictive power. CONCLUSIONS: Using the observed relationships with leaf carbon isotope ratio and morphology to estimate the range of LAI in fossil floras can provide a measure of canopy closure in ancient forests. Similarly, estimates of LAI and LMA for individual taxa can provide comparative measures of light environment and growth strategy of fossil taxa from within a flora.


Asunto(s)
Bosque Lluvioso , Árboles , Australia , Calibración , Fósiles , Fotosíntesis , Hojas de la Planta , Queensland
12.
Melanoma Res ; 30(4): 336-347, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32628430

RESUMEN

Cellular senescence is a major barricade on the path of cancer development, yet proteins secreted from senescent cells exert complex and often discordant effects on subsequent cancer evolution. Somatic genome alternations driving the formation of nevi and melanoma are efficient inducers of cellular senescence. Melanocyte and melanoma cell senescence is likely to come into play as a key factor affecting the course of tumorigenesis and responsiveness to therapy; little mechanistic information has been generated, however, that substantiates this idea and facilitates its clinical translation. Here, we established and characterized a model of melanoma cell senescence in which pharmacologically induced DNA damage triggered divergent ATM kinase- and STING-dependent intracellular signaling cascades and resulted in cell cycle arrest, cytomorphologic remodeling, and drastic secretome changes. Targeted proteome profiling revealed that senescent melanoma cells in this model secreted a panoply of proteins shaping the tumor immune microenvironment. CRISPR-mediated genetic ablation of the p38α and IKKß signaling modules downstream of the ATM kinase severed the link between DNA damage and this secretory phenotype without restoring proliferative capacity. A similar genetic dissection showed that loss of STING signaling prevented type I interferon induction in DNA-damaged melanoma cells but otherwise left the senescence-associated processes in our model intact. Actionable proteins secreted from senescent melanoma cells or involved in senescence-associated intracellular signaling hold potential as markers for melanoma characterization and targets for melanoma treatment.


Asunto(s)
Daño del ADN/genética , Melanoma/genética , Proteómica/métodos , Animales , Senescencia Celular , Modelos Animales de Enfermedad , Humanos , Ratones , Transducción de Señal
13.
J Colloid Interface Sci ; 562: 418-428, 2020 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-31806358

RESUMEN

The anticipated benefits of nano-formulations for drug delivery are well known: for nanomedicines to achieve this potential, new materials are required with predictive and tuneable properties. Excretion of excipients following delivery is advantageous to minimise the possibility of adverse effects; biodegradability to non-toxic products is therefore desirable. With this in mind, we aim to develop tuneable hybrid lipid-block copolymer vesicle formulations where the hydrophilic polymer block is polyethylene glycol (PEG), which has accepted biocompatibility, and the hydrophobic block of the polymer is biodegradable: polycaprolactone (PCL) or polylactide (PLA). We investigate five different block copolymers for the formation of 1:1 phospholipid:polymer hybrid vesicles, compare their properties to the appropriate unitary liposome (POPC) and polymersome systems and assess their potential for future development as nanomedicine formulations. The PEG-PCL polymers under investigation do not form polymersomes and exhibit poor colloidal and/or encapsulation stability in hybrid formulations with lipids. The properties of PEG-PLA hybrid vesicles are found to be more encouraging: they have much enhanced passive loading of a hydrophilic small molecule (carboxyfluorescein) compared to their respective polymersomes and reduces serum induced lysis of the vesicle compared to the liposome. Significantly, burst release from hybrid vesicles can be substantially reduced by making the polymer components of the hybrid vesicle a mixture containing 10 mol% of PEG15-PLA25 that is intermediate in size between the phospholipid and larger PEG45-PLA54 components. We conclude that hybrid lipid/PEG-PLA vesicles warrant further assessment and development as candidate drug delivery systems.


Asunto(s)
Fluoresceínas/química , Fosfatidilcolinas/química , Poliésteres/química , Polietilenglicoles/química , Humanos , Liposomas
15.
Biomater Sci ; 7(8): 3418-3424, 2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31268069

RESUMEN

We report on the synthesis of four poly(2-methyl-2-oxazoline) modified lysine dendrimers with different residual groups or modifications on the dendrimer core, including: amino groups (positive charge), carboxyl groups (negative charge), and two drug molecules, one of which has a high log P. We looked at the in vivo distribution amongst three main liver cell types: hepatocytes, liver sinusoidal endothelial cells (LSECs) and Kupffer cells (KCs) and found differences in cell distribution and uptake concentrations dependent on these residual groups. In particular, the amino-functional polymer showed greater uptake by the hepatocytes whilst the carboxyl-functionalised polymer exhibited greater uptake by KCs and LSECs. These findings provide insight into which professional scavenger cells of the liver remove these types of nanoparticles from the bloodstream and we describe some of the design criteria to consider when creating novel drug delivery systems.


Asunto(s)
Dendrímeros/química , Hígado/metabolismo , Lisina/química , Lisina/metabolismo , Poliaminas/química , Administración Intravenosa , Animales , Transporte Biológico , Femenino , Interacciones Hidrofóbicas e Hidrofílicas , Lisina/administración & dosificación , Lisina/farmacocinética , Ratones , Rodaminas/química , Distribución Tisular
16.
Pharmaceutics ; 11(5)2019 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-31058802

RESUMEN

A special symposium of the Academy of Pharmaceutical Sciences Nanomedicines Focus Group reviewed the current status of the use of nanomedicines for the delivery of biologics drugs. This meeting was particularly timely with the recent approval of the first siRNA-containing product Onpattro™ (patisiran), which is formulated as a lipid nanoparticle for intravenous infusion, and the increasing interest in the use of nanomedicines for the oral delivery of biologics. The challenges in delivering such molecules were discussed with specific emphasis on the delivery both across and into cells. The latest developments in Molecular Envelope Technology® (Nanomerics Ltd, London, UK), liposomal drug delivery (both from an academic and industrial perspective), opportunities offered by the endocytic pathway, delivery using genetically engineered viral vectors (PsiOxus Technologies Ltd, Abingdon, UK), Transint™ technology (Applied Molecular Transport Inc., South San Francisco, CA, USA), which has the potential to deliver a wide range of macromolecules, and AstraZeneca's initiatives in mRNA delivery were covered with a focus on their uses in difficult to treat diseases, including cancers. Preclinical data were presented for each of the technologies and where sufficiently advanced, plans for clinical studies as well as early clinical data. The meeting covered the work in progress in this exciting area and highlighted some key technologies to look out for in the future.

17.
AoB Plants ; 10(3): ply029, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29942458

RESUMEN

Intraspecific plant functional trait variation provides mechanistic insight into persistence and can infer population adaptive capacity. However, most studies explore intraspecific trait variation in systems where geographic and environmental distances co-vary. Such a design reduces the certainty of trait-environment associations, and it is imperative for studies that make trait-environment associations be conducted in systems where environmental distance varies independently of geographic distance. Here we explored trait variation in such a system, and aimed to: (i) quantify trait variation of parent and offspring generations, and associate this variation to parental environments; (ii) determine the traits which best explain population differences; (iii) compare parent and offspring trait-trait relationships. We characterized 15 plant functional traits in eight populations of a shrub with a maximum separation ca. 100 km. Populations differed markedly in aridity and elevation, and environmental distance varied independently of geographic distance. We measured traits in parent populations collected in the field, as well as their offspring reared in greenhouse conditions. Parent traits regularly associated with their environment. These associations were largely lost in the offspring generation, indicating considerable phenotypic plasticity. An ordination of parent traits showed clear structure with strong influence of leaf area, specific leaf area, stomatal traits, isotope δ13C and δ15N ratios, and Narea, whereas the offspring ordination was less structured. Parent trait-trait correlations were in line with expectations from the leaf economic spectrum. We show considerable trait plasticity in the woody shrub over microgeographic scales (<100 km), indicating it has the adaptive potential within a generation to functionally acclimate to a range of abiotic conditions. Since our study shrub is commonly used for restoration in southern Australia and local populations do not show strong genetic differentiation in functional traits, the potential risks of transferring seed across the broad environmental conditions are not likely to be a significant issue.

18.
Int J Pharm ; 534(1-2): 97-107, 2017 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-29017804

RESUMEN

We have employed microfluidics (cross-shaped chip) for the preparation of drug-loaded poly(lactic acid-co-glycolic acid) (PLGA) nanoparticles. The polymer precipitates from an acetone solution upon its controlled laminar mixing (flow focusing) with an aqueous solution of a surfactant, allowing for an operator-independent, up-scalable and reproducible preparative process of nanoformulations. Firstly, using PEGylated surfactants we have compared batch and microfluidic processes, and showed the superior reproducibility of the latter and its strong dependency on the acetone/water ratio (flow rate ratio). We have then focused on the issue of purification from free surfactant, and employed advanced characterization techniques such as flow-through dynamic light scattering as the in-line quality control technique, and field flow fractionation (FFF) with dynamic and static light scattering detection, which allowed the detection of surfactant micelles in mixture with nanoparticles (hardly possible with stand-alone dynamic light scattering). Finally, we have shown that the choice of polymer and surfactant affects the release behaviour of a model drug (paclitaxel), with high molecular weight PLGA (RG756) and low molecular weight surfactant (tocopheryl poly(ethylene glycol) 1000 succinate, TPGS) apparently showing higher burst and accelerated release.


Asunto(s)
Nanopartículas/química , Portadores de Fármacos/química , Células HCT116 , Humanos , Ácido Láctico/química , Microfluídica/métodos , Nanotecnología/métodos , Paclitaxel/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Polímeros/química , Reproducibilidad de los Resultados , Relación Estructura-Actividad , Tensoactivos/química
19.
Psychiatry Res Neuroimaging ; 267: 36-44, 2017 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-28734178

RESUMEN

Abnormalities in the subcortical brain regions that support cognitive functions have been reported in schizophrenia. Relatives of those with schizophrenia often present with psychosis-like traits (schizotypy) and similar cognition as those with schizophrenia. To evaluate the relationships between subcortical structure, schizotypy, and cognitive function, we assessed shape and volume of the hippocampus, amygdala and thalamus in untreated youth at familial high risk for schizophrenia (HRSZ). The sample consisted of 66 HRSZ and 69 age-matched healthy controls (HC). Subjects' cognitive functions and schizotypy were assessed, and T1-weighted brain MRI were analyzed using the FSL software FIRST. The right hippocampus and right amygdala showed significantly increased concavity (inward displacement) in HRSZ compared to HC. While regional subcortical shape displacements were significantly correlated with sustained attention and executive function scores in HC, fewer correlations were seen in HRSZ. This suggests a possible alteration of the local structure-function relationship in subcortical brain regions of HRSZ for these cognitive domains, which could be related to anomalous plasticity.


Asunto(s)
Amígdala del Cerebelo/patología , Hipocampo/patología , Esquizofrenia/patología , Tálamo/patología , Adolescente , Adulto , Amígdala del Cerebelo/diagnóstico por imagen , Atención/fisiología , Niño , Cognición/fisiología , Función Ejecutiva/fisiología , Femenino , Predisposición Genética a la Enfermedad , Hipocampo/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Masculino , Tamaño de los Órganos , Factores de Riesgo , Esquizofrenia/diagnóstico por imagen , Esquizofrenia/genética , Tálamo/diagnóstico por imagen , Adulto Joven
20.
Nanomedicine (Lond) ; 11(6): 577-80, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26911307

RESUMEN

APS 6th International PharmSci Conference 2015 7-9 September 2015 East Midlands Conference Centre, University of Nottingham, Nottingham, UK As part of the 6th APS International PharmSci Conference, a nanomedicine session was organised to address challenges and share experiences in this field. Topics ranged from the reporting on latest results and advances in the development of targeted therapeutics to the needs that the community faces in how to progress these exciting proof of concept results into products. Here we provide an overview of the discussion and highlight some of the initiatives that have recently been established to support the translation of nanomedicines into the clinic.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Nanomedicina/métodos , Animales , Sistemas de Liberación de Medicamentos/economía , Evaluación Preclínica de Medicamentos/economía , Evaluación Preclínica de Medicamentos/métodos , Humanos , Modelos Animales , Nanomedicina/economía , Nanomedicina/educación , Investigación Biomédica Traslacional/economía , Investigación Biomédica Traslacional/educación , Investigación Biomédica Traslacional/métodos , Reino Unido
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