Search results for "O-2"
showing 10 items of 854 documents
Production and transport modelling of Po-210 in DEMO reactor
2022
Abstract One of the generic designs of the nuclear fusion DEMO reactor proposed by the EUROfusion consortium foresees the development of a tritium breeding blanket (BB) relying on the use of the liquid-metal PbLi eutectic alloy as both neutron multiplier and tritium breeder, namely the water-cooled lithium lead (WCLL) BB, whose strengths and weaknesses are well known. This paper focuses the attention on one of the possible disadvantages of such a technology: the production of the highly radiotoxic radionuclide 210Po, which could become a safety issue to be accounted for. The 210Po concentration within the PbLi circuit has been assessed by solving a modified version of Bateman’s equations to…
Biodegradable and pH-sensitive hydrogels for potential colon-specific drug delivery: Characterization and in vitro release studies
2008
A novel pH-sensitive and biodegradable composite hydrogel, based on a methacrylated and succinic derivative of dextran, named Dex-MA-SA, and a methacrylated and succinic derivative of alpha,beta-poly( N-2-hydroxyethyl)- DL-aspartamide (PHEA), named PHM-SA, was produced by photocross-linking. The goal was to obtain a colon-specific drug delivery system, exploiting both the pH-sensitive behavior and the colon-specific degradability. The hydrogel prepared with a suitable ratio between the polysaccharide and the polyaminoacid was characterized regarding its swelling behavior in gastrointestinal simulated conditions, chemical and enzymatic degradability, interaction with mucin, and cell compatib…
Partially Quarternized Amino Functional Poly(methacrylate) Terpolymers: Versatile Drug Permeability Modifiers
2011
Partially quarternized poly(methacrylate) terpolymers (Q-BBMCs) have been synthesized, based on the basic butylated methacrylate copolymer (BBMC/EUDRAGIT E), an excipient approved by the Food and Drug Administration (FDA) and to date mainly applied for tablet coatings. Via straightforward polymer modification reactions, a series of Q-BBMCs with quarternization degrees of 22%, 42%, and 65% has been prepared. Apical to basolateral transport across Caco-2 cell monolayers was investigated, employing the paracellular transported compounds trospium and mannitol. At pH 6.5 quarternization resulted in increased permeation enhancement up to 2.8-fold compared to BBMC, that is, up to 7.3-fold compared…
in vitro biological evaluation of folate-functionalized block copolymer micelles for selective anti-cancer drug delivery.
2008
The main objective of this study was to evaluate the ability of folic acid-functionalized diblock copolymer micelles to improve the delivery and uptake of two poorly water-soluble anti-tumor drugs, tamoxifen and paclitaxel, to cancer cells through folate receptor targeting. The diblock copolymer used in this study comprised a hydrophilic poly[2-(methacryloyloxy)ethyl phosphorylcholine] (MPC) block, carrying at the chain end the folate targeting moiety, and a pH-sensitive hydrophobic poly[2-(diisopropylamino)ethyl methacrylate] (DPA) block (FA-MPC-DPA). The drug-loading capacities of tamoxifen- and paclitaxel-loaded micelles were determined by high performance liquid chromatography and the m…
CONTROLLED RELEASE OF IgG BY NOVEL UV INDUCED POLYSACCHARIDE/POLY(AMINO ACID)HYDROGELS
2009
The development of new protein and peptide drugs needs new delivery systems able to entrap such drugs in safe conditions without affecting their structure and biological activity. In this context, the present work reports a new approach to load IgG, used as a model of therapeutic proteins such as anti-TNF-alpha monoclonal antibodies, into a polymeric system able to release the entrapped IgG in a controlled manner. In particular, new polysaccharide/poly(amino acid) UV induced hydrogels are proposed as colon delivery systems for human IgG. The poly(amino acid), alpha,beta-poly[N-(2-hydroxyethyl)-D,L-aspartamide], has been functionalized with methacrylic anhydride, while the polysaccharide, in…
Cellular Uptake of DNA Block Copolymer Micelles with Different Shapes
2008
The cellular uptake of DNA block copolymer micelles composed of DNA-b-PPO in Caco-2 cells was studied. In particular it was investigated if the shape of micelle aggregates influences the internalization. Rod-like polymeric particles were taken up 12 times more efficiently than their spherical counter parts although they were composed of the same constituents. Furthermore, it was observed that internalization of all the micelle systems was more efficient than the pristine DNA controls. A cytotoxicity assay proved the non-toxic nature of DNA-b-PPO micelle aggregates.
Anti-proliferative effect of main dietary phytosterols and β-cryptoxanthin alone or combined in human colon cancer Caco-2 cells through cytosolic Ca+…
2015
β-cryptoxanthin (β-Cx) and phytosterols (Ps) have potential against different cancer types, including colon cancer. However, their combined action has not been reported so far. Human colon cancer Caco-2 cells were treated 24 h with β-Cx and/or main dietary Ps (β-sitosterol, campesterol and stigmasterol), alone or in combination, at concentrations compatible with physiological human serum levels. A decrease in cell viability due to apoptosis (rise in sub-G1 population and exposure of membrane phosphatidylserine) was accompanied with dephosphorylation of BAD, mitochondrial depolarization and caspase 3-dependent PARP cleavage, with intracellular Ca2+ influx and increase of RONS levels as initi…
Bioaccessibility and bioavailability of bioactive compounds from yellow mustard flour and milk whey fermented with lactic acid bacteria.
2021
Microbial fermentation with lactic acid bacteria (LAB) is a natural food biopreservation method. Yellow mustard and milk whey are optimum substrates for LAB fermentation. The aim of the present study was to evaluate the bioaccessibility and bioavailability of bioactive compounds from yellow mustard flour and milk whey both with and without LAB fermentation. All extracts were subjected to a simulated digestion process. Total polyphenols, DL-3-phenyllactic acid (PLA), lactic acid, and the antioxidant activity were determined in the studied matrices before and after simulated digestion. Yellow mustard flour was significantly richer in total polyphenols, whereas significantly higher concentrati…
Tributyltin(IV) ferulate, a novel synthetic ferulic acid derivative, induces autophagic cell death in colon cancer cells: From chemical synthesis to …
2020
Ferulic acid (FA) is a natural phenolic phytochemical that has low toxicity and exhibits therapeutic effects against various diseases, behaving as an antioxidant. FA also displays modest antitumor properties that have been reported at relatively high concentrations. With the aim of improving the anti-tumor efficacy of FA, we synthesized the novel compound tributyltin(IV) ferulate (TBT-F). The coordination environment at the tin center was investigated spectroscopically. Following synthesis, chemical characterization and computational analysis, we evaluated TBT-F effects in colon cancer cells. The results showed that TBT-F, at nanomolar range concentrations, was capable of reducing the viabi…
7keto-stigmasterol and 7keto-cholesterol induce differential proteome changes to intestinal epitelial (Caco-2) cells
2015
Abstract Recent studies have expanded the appreciation of the roles of oxysterols triggering inflammatory, immune cytotoxic and apoptotic processes, but have not been considered for proteome analysis. A comparative proteomic study in intestinal epithelial cell cultures incubated (60 μM/24 h) with 7keto-cholesterol or 7keto-stigmasterol was performed. The influence of both compounds was studied following the nLC-TripleTOF analysis. Findings were compared to results for control cultures. In the principal component analysis (PCA) of proteome patterns, two components were extracted accounting for 99.8% of the variance in the protein expression. PCA analysis clearly discriminated between the per…