1,365 research outputs found
Utilization of Green Formulation Technique and Efficacy Estimation on Cell Line Studies For Dual Anticancer Drug Therapy With Niosomes
The aim of the present study was to prepare niosome formulations for the simultaneous encapsulation, dual drug therapy, of two anticancer drugs by the ecological probe sonication method. Poloxamer and sorbitan monostearate were used as surface active agents in niosomes, and the water soluble doxorubicin and poorly-water soluble paclitaxel were used as anticancer drugs. Thorough physicochemical analysis were performed for the niosomes, and their cytotoxicity and activity were evaluated on MCF-7 and PC3-MM2 cancer cell lines. Prepared niosomes were small in size with sizes ranging from 137 nm to 893 nm, and entrapment efficiencies were high, ranging from 91.24% to 99.99%. During the four weeks stability testing, the particle size remained stable. The niosomal formulations showed in vitro sustained drug release profiles for doxorubicin and clearly increased the dissolution rate of poorly water soluble paclitaxel. The incorporation of both the drugs into niosomes improved cell penetration and antiproliferative activity of the drugs PC3-MM2 cell lines. As a conclusion, doxorubicin and paclitaxel loaded niosome formulations resulted in relatively stable, small sized niosomes with improved drug release profiles, low toxicity, better cell penetration and antiproliferative activity. The niosomes showed synergistic effect due to the presence of both drugs, which can overcome multidrug resistance.Peer reviewe
Damage threshold of CuCrFeTiV high entropy alloys for nuclear fusion reactors
A CuCrFeTiV high entropy alloy was prepared and irradiated with swift heavy ions in order to check its adequacy for use as a thermal barrier in future nuclear fusion reactors. The alloy was prepared from the elemental powders by ball milling, followed by consolidation by spark plasma sintering at 1178 K and 65 MPa. The samples were then irradiated at room temperature with 300 keV Ar+ ions with fluences in the 3 Ă 1015 to 3 Ă 1018 Ar+/cm2 range to mimic neutron-induced damage accumulation during a duty cycle of a fusion reactor. Structural changes were investigated by X-ray diffraction, and scanning electron microscopy and scanning transmission electron microscopy, both coupled with X-ray energy dispersive spectroscopy. Surface irradiation damage was detected for high fluences (3 Ă 1018 Ar+/cm2) with formation of blisters of up to 1 ÎŒm in diameter. Cross-sectional scanning transmission electron microscopy showed the presence of intergranular cavities only in the sample irradiated with 3 Ă 1018 Ar+/cm2, while all irradiation experiments produced intragranular nanometric-sized bubbles with increased density for higher Ar+ fluence. The Williamson-Hall method revealed a decrease in the average crystallite size and an increase in residual strain with increasing fluence, consistent with the formation of Ar+ bubbles at the irradiated surface.publishedVersio
Optogenetic Recruitment of Dorsal Raphe Serotonergic Neurons Acutely Decreases Mechanosensory Responsivity in Behaving Mice
The inhibition of sensory responsivity is considered a core serotonin function, yet this hypothesis lacks direct support due to methodological obstacles. We adapted an optogenetic approach to induce acute, robust and specific firing of dorsal raphe serotonergic neurons. In vitro, the responsiveness of individual dorsal raphe serotonergic neurons to trains of light pulses varied with frequency and intensity as well as between cells, and the photostimulation protocol was therefore adjusted to maximize their overall output rate. In vivo, the photoactivation of dorsal raphe serotonergic neurons gave rise to a prominent light-evoked field response that displayed some sensitivity to a 5-HT1A agonist, consistent with autoreceptor inhibition of raphe neurons. In behaving mice, the photostimulation of dorsal raphe serotonergic neurons produced a rapid and reversible decrease in the animals' responses to plantar stimulation, providing a new level of evidence that serotonin gates sensory-driven responses.ERC 250334, 5-HT OptogeneticMSCA 220098info:eu-repo/semantics/publishedVersio
Behavior of Cu-Y2O3 and CuCrZr-Y2O3 composites before and after irradiation
ABSTRACT: The Cu-Y2O3 and CuCrZr-Y2O3 materials have been devised as thermal barriers in nuclear fusion reactors. It is expected that in the nuclear environments, the materials should be working on extreme conditions of irradiation. In this work the Cu-Y2O3 and CuCrZr-Y2O3 were prepared and then irradiated in order to understand the surface irradiation resistance of the material. The composites were prepared in a glove box and consolidated with spark plasma sintering. The microstructures revealed regions of Y2O3 dispersion and Y2O3 agglomerates both in the Cu matrix and in the CuCrZr. The irradiated samples did not show any surface modification indicating that the materials seem to be irradiation resistant in the present situation. The thermal conductivity values for all the samples measured are lower than pure Cu and higher than pure W, however are higher than those expected, and therefore, the application of these materials as thermal barriers is compromised.info:eu-repo/semantics/publishedVersio
Dissecting the conserved NPxxY motif of the M<sub>3</sub> muscarinic acetylcholine receptor: critical role of Asp-7.49 for receptor signaling and multiprotein complex formation
Acetylcholine challenge produces M-3 muscarinic acetylcholine receptor activation and accessory/scaffold proteins recruitment into a signalsome complex. The dynamics of such a complex is not well understood but a conserved NPxxY motif located within transmembrane 7 and juxtamembrane helix 8 of the receptor was found to modulate G protein activation. Here by means of receptor mutagenesis we unravel the role of the conserved M-3 muscarinic acetylcholine receptor NPxxY motif on ligand binding, signaling and multiprotein complex formation. Interestingly, while a N7.49D receptor mutant showed normal ligand binding properties a N7.49A mutant had reduced antagonist binding and increased affinity for carbachol. Also, besides this last mutant was able to physically couple to G alpha(q/11) after carbachol challenge it was neither capable to activate phospholipase C nor phospholipase D. On the other hand, we demonstrated that the Asn-7.49 is important for the interaction between M3R and ARF1 and also for the formation of the ARF/Rho/beta gamma signaling complex, a complex that might determine the rapid activation and desensitization of PLD. Overall, these results indicate that the NPxxY motif of the M-3 muscarinic acetylcholine receptor acts as key conformational switch for receptor signaling and multiprotein complex formation
Systematic in vitro biocompatibility studies of multimodal cellulose nanocrystal and lignin nanoparticles
Natural biopolymer nanoparticles (NPs), including nanocrystalline cellulose (CNC) and lignin, have shown potential as scaffolds for targeted drug delivery systems due to their wide availability, costâefficient preparation, and anticipated biocompatibility. Since both CNC and lignin can potentially cause complications in cell viability assays due to their ability to scatter the emitted light and absorb the assay reagents, we investigated the response of bioluminescent (CellTiterâGloÂź), colorimetric (MTTÂź and AlamarBlueÂź) and fluorometric (LIVE/DEADÂź) assays for the determination of the biocompatibility of the multimodal CNC and lignin constructs in murine RAW 264.7 macrophages and 4T1 breast adenocarcinoma cell lines. Here, we have developed multimodal CNC and lignin NPs harboring the radiometal chelator DOTA (1,4,7,10âtetraazacyclododecaneâ1,4,7,10âtetraacetic acid) and the fluorescent dye Cyanine 5 for the investigation of nanomaterial biodistribution in vivo with nuclear and optical imaging, which were then used as the model CNC and lignin nanosystems in the cell viability assay comparison. CellTiterâGloÂź based on the detection of ATPâdependent luminescence in viable cells revealed to be the best assay for both nanoconstructs for its robust linear response to increasing NP concentration and lack of interference from either of the NP types. Both multimodal CNC and lignin NPs displayed low cytotoxicity and favorable interactions with the cell lines, suggesting that they are good candidates for nanosystem development for targeted drug delivery in breast cancer and for theranostic applications. Our results provide useful guidance for cell viability assay compatibility for CNC and lignin NPs and facilitate the future translation of the materials for in vivo applications.Peer reviewe
LinTT1 peptide-functionalized liposomes for targeted breast cancer therapy
Breast cancer, with around 2 million new cases in 2019, is the second most common cancer worldwide and the second leading cause of cancer death among females. The aim of this work is to prepare a targeting nanoparticle through the conjugation of LinTT1 peptide, a specific molecule targeting p32 protein overexpressed by breast cancer and cancer associated cells, on liposomes' surface. This approach increases the cytotoxic effects of doxorubicin (DOX) and sorafenib (SRF) co-loaded in therapeutic liposomes on both 2D and 3D breast cancer cellular models. The liposome functionalization leads to a higher interaction with 3D breast cancer spheroids than bare ones. Moreover, interaction studies between LinTT1-functionalized liposomes and M2 primary human macrophages show an internalization of 50% of the total nanovesicles that interact with these cells, while the other 50% results only associated to cell surface. This finding suggests the possibility to use the amount of associated liposomes to enrich the hypoxic tumor area, exploiting the ability of M2 macrophages to accumulate in the central core of tumor mass. These promising results highlight the potential use of DOX and SRF co-loaded LinTT1-functionalized liposomes as nanomedicines for the treatment of breast cancer, especially in triple negative cancer cells.Peer reviewe
Superfast and controllable microfluidic inking of anti-inflammatory melanin-like nanoparticles inspired by cephalopods
Here, a microfluidic approach for superfast melanin-like nanoparticle preparation with tunable size and monodispersity is reported. The particles formed have similar chemical composition to those prepared by the bulk method, and show reactive oxygen species scavenging behaviour and inflammatory macrophage phenotype switching capability, suggesting their potential for anti-inflammatory applications.Peer reviewe
Preparation and characterization of dentin phosphophoryn-derived peptide-functionalized lignin nanoparticles for enhanced cellular uptake
The surface modification of nanoparticles (NPs) using different ligands is a common strategy to increase NPâcell interactions. Here, dentin phosphophorynâderived peptide (DSS) lignin nanoparticles (LNPs) are prepared and characterized, the cellular internalization of the DSSâfunctionalized LNPs (LNPsâDSS) into three different cancer cell lines is evaluated, and their efficacy with the widely used iRGD peptide is compared. It is shown that controlled extent of carboxylation of lignin improves the stability at physiological conditions of LNPs formed upon solvent exchange. Functionalization with DSS and iRGD peptides maintains the spherical morphology and moderate polydispersity of LNPs. The LNPs exhibit good cytocompatibility when cultured with PC3âMM2, MDAâMBâ231, and A549 in the conventional 2D model and in the 3D cell spheroid morphology. Importantly, the 3D cell models reveal augmented internalization of peptideâfunctionalized LNPs and improve antiproliferative effects when the LNPs are loaded with a cytotoxic compound. Overall, LNPsâDSS show equal or even superior cellular internalization than the LNPsâiRGD, suggesting that DSS can also be used to enhance the cellular uptake of NPs into different types of cells, and release different cargos intracellularly.Peer reviewe
Cymbopogon winterianus essential oil attenuates bleomycin-induced pulmonary fibrosis in a murine model
The essential oil of Cymbopogon winterianus (EOCW) is a natural product with antioxidant, anti-inflammatory, and antifibrotic properties. We studied the effect of EOCW in the progression of histological changes of pulmonary fibrosis (PF) in a rodent model. The oil was obtained by hydrodistillation and characterized using gas chromatographymass spectrometry. Intratracheal instillation of bleomycin was performed in 30 rats to induce PF, while Sham animals were subjected to instillation of saline solution. The treatment was performed using daily oral administration of distilled water, EOCW at 50, 100, and 200 mg/kg, and deflazacort (DFC). After 28 days, hemogram and bronchoalveolar lavage fluid (BALF), tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) were assayed. Histological grading of PF, immunohistochemical expression of -smooth muscle actin (-SMA), and transforming growth factor- (TGF-) were also analyzed. The EOCW major compounds were found to be citronellal, geraniol, and citronellol. EOCW significantly reduced inflammation in BALF, reduced MDA levels, and increased SOD activity. EOCW attenuated histological grading of PF and reduced immunohistochemical expression of -SMA and TGF- in a dose-dependent way, likely due to the reduction of oxidative stress, inflammation, and TGF--induced myofibroblast differentiation.This research was financed by the Coordenação Aperfeiçoamento de Pessoal de Nivel
Superior (CAPES), Fundação de Amparo à Pesquisa do Estado de Sergipe (FAPITEC), and Conselho
Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq). EBS wishes to acknowledge the
sponsorship of the project UIDB/04469/2020 (strategic fund) from the Portuguese Science and
Technology Foundation, Ministry of Science and Education (FCT/MEC) through national funds, and
was co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio
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