705 research outputs found
Polymer coated gold nanoshells for combinational photochemotherapy of pancreatic cancer with gemcitabine
Pancreatic cancer is one of the most lethal malignancies with limited therapeutic options and
dismal prognosis. Gemcitabine is the front-line drug against pancreatic cancer however with limited
improvement of therapeutic outcomes. In this study we envisaged the integration of GEM with
gold nanoshells which constitute an interesting class of nanomaterials with excellent photothermal
conversion properties. Nanoshells were coated with thiol-capped poly(ethylene glycol) methacrylate
polymers of different molecular weight via Au–S attachment. It was found that the molecular
weight of the polymers affects the in vitro performance of the formulations; more importantly we
demonstrate that the EC50
of nanoshell loaded GEM can be suppressed but fully restored and even
improved upon laser irradiation. Our proposed nanoformulations outperformed the cytotoxicity of the
parent drug and showed confined synergism under the tested in vitro conditions
Harmonic wavelets based response evolutionary power spectrum determination of linear and nonlinear structural systems with singular matrices
Mahi-mahi (Coryphaena hippurus) life development: morphological, physiological, behavioral and molecular phenotypes.
BackgroundMahi-mahi (Coryphaena hippurus) is a commercially and ecologically important fish species that is widely distributed in tropical and subtropical waters. Biological attributes and reproductive capacities of mahi-mahi make it a tractable model for experimental studies. In this study, life development of cultured mahi-mahi from the zygote stage to adult has been described.ResultsA comprehensive developmental table has been created reporting development as primarily detailed observations of morphology. Additionally, physiological, behavioral, and molecular landmarks have been described to significantly contribute in the understanding of mahi life development.ConclusionRemarkably, despite the vast difference in adult size, many developmental landmarks of mahi map quite closely onto the development and growth of Zebrafish and other warm-water, active Teleost fishes
The effects of temperature acclimation on swimming performance in the pelagic Mahi-mahi (Coryphaena hippurus)
Mahi-mahi (Coryphaena hippurus) are a highly migratory pelagic fish, but
little is known about what environmental factors drive their broad
distribution. This study examined how temperature influences aerobic scope and
swimming performance in mahi. Mahi were acclimated to four temperatures
spanning their natural range (20, 24, 28, and 32{\deg}C; 5-27 days) and
critical swimming speed (Ucrit), metabolic rates, aerobic scope, and optimal
swim speed were measured. Aerobic scope and Ucrit were highest in
28{\deg}C-acclimated fish. 20{\deg}C-acclimated mahi experienced significantly
decreased aerobic scope and Ucrit relative to 28{\deg}C-acclimated fish (57 and
28% declines, respectively). 32{\deg}C-acclimated mahi experienced increased
mortality and a significant 23% decline in Ucrit, and a trend for a 26% decline
in factorial aerobic scope relative to 28{\deg}C-acclimated fish. Absolute
aerobic scope showed a similar pattern to factorial aerobic scope. Our results
are generally in agreement with previously observed distribution patterns for
wild fish. Although thermal performance can vary across life stages, the
highest tested swim performance and aerobic scope found in the present study
(28{\deg}C), aligns with recently observed habitat utilization patterns for
wild mahi and could be relevant for climate change predictions.Comment: 24 pages, 3 figures main text, 6 figures supplemental text, published
in Frontiers in Marine Science
https://www.frontiersin.org/articles/10.3389/fmars.2021.654276/ful
Immune and inflammatory responses in TNF alpha-deficient mice: A critical requirement for TNF alpha in the formation of primary B cell follicles, follicular dendritic cell networks and germinal centers, and in the maturation of the humoral immune response
To investigate the role of TNF alpha in the development of in vivo immune response we have generated TNF alpha-deficient mice by gene targeting. Homozygous mutant mice are viable and fertile, develop lymph nodes and Peyer's patches and show no apparent phenotypic abnormalities, indicating that TNF alpha is not required for normal mouse development. In the absence of TNF alpha mice readily succumb to L. monocytogenes infections and show reduced contact hypersensitivity responses. Furthermore, TNF alpha knockout mice are resistant to the systemic toxicity of LPS upon D-galactosamine sensitization, yet they remain sensitive to high doses of LPS alone. Most interestingly, TNF alpha knockout mice completely lack splenic primary B cell follicles and cannot form organized follicular dendritic cell (FDC) networks and germinal centers. However, despite the absence of B cell follicles, Ig class-switching can still occur, yet deregulated humoral immune responses against either thymus-dependent (TD) or thymus-independent (TI) antigens are observed. Complementation of TNF alpha functioning by the expression of either human or murine TNF alpha transgenes is sufficient to reconstitute these defects, establishing a physiological role for TNF alpha in regulating the development and organization of splenic follicular architecture and in the maturation of the humoral immune response
Dual controlled delivery of squalenoyl-gemcitabine and paclitaxel using thermo-responsive polymeric micelles for pancreatic cancer
In this study we report the synthesis of a themroresponsive block copolymer by reversible addition
fragmentation transfer polymerization comprising poly(2-ethylhexyl methacrylate)-b-poly[di(ethylene
glycol)methyl ether methacrylate-co-oligo(ethylene glycol)methyl ether methacrylate] as hydrophobic
and thermoresponsive blocks respectively. The polymer self-assembles into sub-50 micelles and can
carry simultaneously two drug molecules, namely squalene-gemcitabine and paclitaxel. Both drugs can
be released from the micellar compartment in a thermally controlled manner owing to the controllable
disruption of the micellar corona above the lower critical solution temperature of the polymer. We
demonstrate that the formulation augments synergistically the cytotoxicity of the two drugs in vitro
against a model pancreatic cancer cell line. More importantly, it is shown that the polymer exerts a
direct interaction with the cell membrane which further augments the cytotoxicity of the drug cargo in
a thermally controlled manne
Harnessing photochemical internalization with dual degradable nanoparticles for combinatorial photo-chemotherapy.
Light-controlled drug delivery systems constitute an appealing means to direct and confine drug release spatiotemporally at the site of interest with high specificity. However, the utilization of light-activatable systems is hampered by the lack of suitable drug carriers that respond sharply to visible light stimuli at clinically relevant wavelengths. Here, a new class of self-assembling, photo- and pH-degradable polymers of the polyacetal family is reported, which is combined with photochemical internalization to control the intracellular trafficking and release of anticancer compounds. The polymers are synthesized by simple and scalable chemistries and exhibit remarkably low photolysis rates at tunable wavelengths over a large range of the spectrum up to the visible and near infrared regime. The combinational pH and light mediated degradation facilitates increased therapeutic potency and specificity against model cancer cell lines in vitro. Increased cell death is achieved by the synergistic activity of nanoparticle-loaded anticancer compounds and reactive oxygen species accumulation in the cytosol by simultaneous activation of porphyrin molecules and particle photolysis
Solid lipid nanoparticles self-assembled from spray dried microparticles
We report the self-assembly of anti-cancer drug-loaded solid lipid nanoparticles (SLNs) from spray dried microparticles comprising poly(vinylpyrrolidone) (PVP) loaded with glyceryl tristearate (GTS) and either indomethacin (IMC) or 5-fluorouracil (5-FU). When the spray dried microparticles are added to water, the PVP matrix dissolves and the GTS and drug self-assemble into SLNs. The SLNs provide a non-toxic delivery platform for both hydrophobic (indomethacin) and hydrophilic (5-fluorouracil) drugs. They show extended release profiles over more than 24 h, and in permeation studies the drug cargo is seen to accumulate inside cancer cells. This overcomes major issues with achieving local intestinal delivery of these active ingredients, in that IMC permeates well and thus will enter the systemic circulation and potentially lead to side effects, while 5-FU remains in the lumen of the small intestine and will be secreted without having any therapeutic benefit. The SLN formulations are as effective as the pure drugs in terms of their ability to induce cell death. Our approach represents a new and simple route to the fabrication of SLNs: by assembling these from spray-dried microparticles on demand, we can circumvent the low storage stability which plagues SLN formulations
A20 Prevents Inflammasome-Dependent Arthritis by Inhibiting Macrophage Necroptosis Through Its ZnF7 Ubiquitin-Binding Domain
Deficiency in the deubiquitinating enzyme A20 causes severe inflammation in mice, and impaired A20 function is associated with human inflammatory diseases. A20 has been implicated in negatively regulating NF-κB signalling, cell death and inflammasome activation; however, the mechanisms by which A20 inhibits inflammation in vivo remain poorly understood. Genetic studies in mice revealed that its deubiquitinase activity is not essential for A20 anti-inflammatory function. Here we show that A20 prevents inflammasome-dependent arthritis by inhibiting macrophage necroptosis and that this function depends on its zinc finger 7 (ZnF7). We provide genetic evidence that RIPK1 kinase-dependent, RIPK3-MLKL-mediated necroptosis drives inflammasome activation in A20-deficient macrophages and causes inflammatory arthritis in mice. Single-cell imaging revealed that RIPK3-dependent death caused inflammasome-dependent IL-1β release from lipopolysaccharide-stimulated A20-deficient macrophages. Importantly, mutation of the A20 ZnF7 ubiquitin binding domain caused arthritis in mice, arguing that ZnF7-dependent inhibition of necroptosis is critical for A20 anti-inflammatory function in vivo
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