148 research outputs found
Polymer-gold nanoparticulate formulations for combinational photochemotherapy of pancreatic cancer
Pancreatic cancer is one of the most deadly of all types of cancer, with a yearly incident that equals its mortality. Gemcitabine (Gem) is currently the first-line chemotherapeutic drug used to treat pancreatic cancer. The major deficiencies of Gem therapy are poor cell membrane permeability, short plasma half-life and toxic side effects. In order to improve the pharmacokinetic characteristics and overcome the obstacles to achieve effective drug delivery, a nanoparticulate drug delivery system can be utilised; gold nanoparticles (GNPs) have been investigated as carriers for drug delivery due to their appealing physicochemical and optical properties. This research project concerns the development of a new generation of GNPs for cancer treatment by co-delivering anti-cancer drugs in combination with laser-induced photothermal effects confined at the diseased areas. Gold nanoshells (GNShells) were synthesised with the capability to carry and deliver Gem and exert phototherapeutic properties. Protein repellent thiol capped poly (ethylene glycol) methyl ether methacrylate polymers were synthesised by RAFT polymerisation and used as efficient particle stabilising ligands. Significant stability enhancement was achieved allowing for the co-functionalisation of GNShells with Gem for applications in in vitro assays against pancreatic cancer cells. GNShells mediated strong photothermal effect owing to their strong surface plasmon absorption in the red/NIR region. This property was exploited to enhance the toxicity of Gem using laser light as the external stimulus. The concerted antitumor activity of Gem with the photothermal effect of the GNShells upon irradiation with a continuous wave laser, increase the cellular uptake and efficacy of Gem-loaded GNShells against MiaPaCa-2 cells. Therefore, the proposed nanoformulation might provide an active strategy for synergistic chemo-photothermal combined therapy
Controlled Co-Delivery of Chemotherapeutic Drugs using Stimuli-Responsive Nano-formulations for Pancreatic Cancer
No abstract
Improving the thermal stability and fire safety of PVC formworks
This study examines the impact of materials and compositions on the fire design considerations of plastic formworks, focusing on the influence of building materials on the fire resistance of buildings, the safety of occupants, and the environment. The study investigates the chemical properties of formworks, including heat resistance, UV resistance, and smoke suppressant properties, which are essential for developing and optimizing formwork products. The research covers three key areas for improving thermal behaviour of PVC: (a) the development and evaluation of new metal complexes with dipentaerythritol, (b) cementitious compositions as a novel class of thermal stabilizers, and (c) the development and evaluation of a new synergistic thermo stabilizer based on sodium hexametaphosphate. To investigate the thermal degradation procedures of each additive for fire retardancy workability, the study utilizes advanced techniques such as thermal gravimetric analysis (TGA), fourier transform infrared spectroscopy (FT-IR), X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), and Energy Dispersive Spectroscopy (EDS). The results demonstrate that hydrated cementitious materials are more effective in stabilizing PVC than metal chelates of dipentaerythritol or synergistic stabilizers based on sodium hexametaphosphate. Moreover, the study found that zinc, as a metal complex with dipentaerythritol, is more effective than traditional stabilizers. The research on cementitious compositions also revealed their highly economical, environmentally friendly, and compatible nature, making them an attractive option for use in the PVC formwork construction industry. The study also highlights the positive impact of calcium metaborate and sodium hexametaphosphate in improving the thermal behaviour of PVC. The study emphasizes the significance of fire-resistant materials in ensuring the safety of occupants and the environment, and the need for innovative solutions to enhance their effectiveness. In conclusion, this research underscores the importance of materials and compositions in the fire design considerations of plastic formworks. The study's findings can imply the development of more effective and sustainable fire-resistant materials and promote safer buildings
Factors Influencing Social Media Usage in the US
Given the immense shifts the social networking sites and applications have brought about, a considerable number of researchers in the field of communication studies have turned to study different aspects of social media usage and factors influencing it. This study gathered data from 33318 US non-institutionalized citizens over 18 including 17079 females and 16239 males; they were members of web panelists of Pew, and their answers revealed that a majority of this online participants used a kind of social media. The results of this study revealed women use social media more than men, and religious people more than non-religious people. In addition, the results indicated that married people are the least users of social media in comparison with other marital groups. Our results showed that all demographics are significantly related to social media usage. But this significance can be somehow misleading because of weak practical effect sizes. Except for marital status and age Cramer’s V values are too small and their significance may have nothing to say but sensitivity to the degree of freedom
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
Catecholamines are active plant-based drug compounds in Pisum sativum, Phaseolus vulgaris and Vicia faba Species
Introduction: Catecholamines (L-DOPA and dopamine) are the key metabolites found in nervous system and their endogenous deficiency is associated with different patho-physiological disorders. Therefore, it is important to screen the new herbal sources of catecholamines for drug preparation. In this study, the amount of L-DOPA and dopamine were investigated in the leaves and roots of three species from legume family such as Pisum sativum (garden pea), Phaseolus vulgaris (haricot bean) and Vicia faba (broad bean); using TLC and HPLC. Methods: The seeds of P. sativum, P. Vulgaris and V. faba were treated and cultured under the glasshouse conditions. The extraction from 1 gram of each plant sample was obtained and assayed for L-DOPA and dopamine using thin layer chromatography (TLC) and reversed-phase HPLC. Results: The results indicated that all cultivars accumulated different levels of L-DOPA and dopamine in leaves and roots. The quantitative results showed that the metabolites concentrations were high in the leaves of P. Sativum and V. faba compared to that in roots. Conclusion: The present study may provide a new avenue for preparation and estimation of L-DOPA and dopamine from plant sources and may be used for further analysis and therapeutic studies.</p
α-Synuclein interacts with lipoproteins in plasma
Parkinson’s disease (PD) is an age-related neurodegenerative disorder characterized by dopaminergic neural cell death in the substantia nigra of the brain and α-synuclein (α-syn) accumulation in Lewy bodies. α-Syn can be detected in blood and is a potential biomarker for PD. It has been shown recently that α-syn can pass through the blood-brain barrier (BBB), but the mechanism is not yet understood. We hypothesized that α-syn could interact with lipoproteins, and in association with these particles, could pass through the BBB. Here, we show that apoE, apoJ, and apoA1, but not apoB, were co-immunocaptured along with α-syn from human blood plasma, suggesting that α-syn is associated with high density lipoproteins (HDL). This association was also supported by experiments involving western blotting of plasma fractions separated by gel filtration,which revealed that α-syn was found in fractions identified as HDL. Interestingly, we could also detect α-syn and ApoJ in the intermediate fraction between HDL and LDL, referred to as lipoprotein (a) (Lp(a)), which has an important role in cholesterol metabolism. Overall, the results provide best support for the hypothesis that α-syn interacts with HDL, and this has potential implications for transport of α-syn from the brain to peripheral blood, across the BBB
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