Organic NPs

Acetylation [48] and PEGylation [49, 50] were also shown to influence the gene delivery efficiency of PEL Hosseinkhani et al. [48] reacted PEI with acetic anhydride to acetylate 80% of the primary and 20% of the secondary amines. This acetylated PEI was shown to have enhanced gene delivery efficiency over unmodified PEI for MSCs. Chen et al. [51] showed that a PEG-PEl copolymer had better gene delivery efficiency than cationic liposomes and did not affect the bionomics, proliferation and differentiation potential of MSCs. 

PLGA NPs. Mahor et al. [52] used branched PEI as a transfecting agent for DNA encapsulated in HA biomaterials and obtained significantly higher expression levels than for naked DNA. 

Poly(beta-amino esters) are cationic, hydrolytically degradable polymers that can be produced as polymeric NPs for gene delivery. Green et al. [71] developed small ( 200 nm), positively charged ( 10 mV), polymeric NPs by the self assembly of poly(beta-amino esters) and DNA. These NPs had four times greater gene delivery efficacy than those observed for Lipofectamine 2000 in human embryonic stem (ES) cells. These materials exhibited minimal toxicity and did not adversely affect the colony morphology or cause nonspecific differentiation of the ES cells. 

PEG as such is not used as an NP. Repeating PEG moieties are usually added to pol5miers to alter electrostatic binding properties and increase hydrophilicity of NPs. The bulky nature of PEGylated polymers can also protect the NPs from degradation by cellular enzymes, increase their stability and prevent aggregation. PEGylation also enhances the transfection efficiency of NPs [74]. 

HA has been used to modify the surface charge, dispersing stability and buffering capacity of polymers such as PEI and chitosan to form NPs for non-viral gene delivery [86]. NPs made of HA and chitosan showed lower cytotoxicity and induced a higher rate of gene integration in neural stem cells and spinal cord slice tissue compare to those obtained with PEI [86]. Similar results were also obtained with PEI-introduced chitosan NPs for rat MSCs [55]. 

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Silver nanoclusters exhibiting cathodic hot electron-induced ECL with considerable potential of its use as probes in molecular sensing have also been reported [109]. Most of the ECL studies have been performed using organic molecules however, few studies have been performed on organic NP ECL [110]. By direct reaction between HAuCLi and Imninol in aqueous solutions, luminol-reduced AuNPs have been synthesized, in recent years, where diameter of the NPs... 

Lam et al report on a powerful organic NP that can be constructed by using a single organic building block, a porphyrin-cholic acid (CA) hybrid polymer... 

A plethora of different nanosized particles have been adopted for biomedical and pharmaceutical applications, including inorganic and organic nanoparticles (NPs). The most commonly adopted inorganic NPs include magnetic particles (mainly for imaging), silica particles, metal oxides, carbides, borates, sulfides, hydroxides, and salts (eg, calcium phosphate, calcium carbonate, calcium sulfate). Organic NPs include oil-in-water (0/W) emulsions, double emulsions [water-in-oil-in-water (W/OAV)], and polymer-based NPs. Different polymer-based nanosystems are adopted and include polymer micelles, dendrimers, polymerosomes, and polymeric NPs. 

During the last decade the immobilization of NPs by self-assembled and ordered matrices attracted a lot of attention due to the possibility not only to localize, but also to organize NPs in ordered arrays that may find new applications. One group of... 

Biisslcr et ai [110-113] treated charge recombination in organic LEDs in terms of chemical kinetics. The probability of recombination depends on the ratio of recombination rate ynp-np (where y represents a bimolecular rate constant) and the transition time (itr=dlpE) of the charge carriers through the device. 

The Table shows a great spread in Kd-values even at the same location. This is due to the fact that the environmental conditions influence the partition of plutonium species between different valency states and complexes. For the different actinides, it is found that the Kd-values under otherwise identical conditions (e.g. for the uptake of plutonium on geologic materials or in organisms) decrease in the order Pu>Am>U>Np (15). Because neptunium is usually pentavalent, uranium hexavalent and americium trivalent, while plutonium in natural systems is mainly tetravalent, it is clear from the actinide homologue properties that the oxidation state of plutonium will affect the observed Kd-value. The oxidation state of plutonium depends on the redox potential (Eh-value) of the ground water and its content of oxidants or reductants. It is also found that natural ligands like C032- and fulvic acids, which complex plutonium (see next section), also influence the Kd-value. 

The above information was used to develop conceptual flowsheets for the extraction of all of the actinides (U, Np, Pu, Am, and Cm) from high-level liquid waste from PUREX processing using 0.4 M 0fuel using 0.8 M DHDECMP in DEB. In both flowsheets, no oxidation state of Pu is necessary since the III, IV, and VI state extract into the organic phase. 

Conceptual Flowsheet for the Extraction of Actinides from HLLW. Figure 5 shows a conceptual flowsheet for the extraction of all the actinides (U, Np, Pu, Am, and Cm) from HLLW using 0.4 M 0< >D[IB]CMP0 in DEB. The CMPO compound was selected for this process because of the high D m values attainable with a small concentration of extractant and because of the absence of macro-concentrations of uranyl ion. Distribution ratios relevant to the flowsheet are shown in previous tables, IV, V, VI, and VII and figures 1 and 2. One of the key features of the flowsheet is that plutonium is extracted from the feed solution and stripped from the organic phase without the addition of any nitric acid or use of ferrous sulfamate. However, oxalic acid is added to complex Zr and Mo (see Table IV). The presence of oxalic acid reduces any Np(VI) to Np(IV) (15). The presence of ferrous ion, which is... 

Balakin KV, Ivanenkov YA, Skorenko AV, Nikolsky YV, Savchuk NP, Ivashchenko AA. In silico estimation of DMSO solubility of organic compounds for bioscreening. J Biomol Scr 2004 9 22-31. 

Under these conditions rather low limiting cnrrents arise that are independent of potential np to the desorption potential of the organic snbstance. This effect can be explained in terms of the difficulties encountered by the reactant metal ions when, in penetrating from the bulk solution to the electrode surface, they cross the adsorbed layer. 

Carotenoids are also fonnd in photosynthetic bacteria and in some fimgi [16]. Snch componnds often have qnite nniqne stmctnral featnres reflecting their biosynthetic origin. Carotenoids fonnd in insects and animals are the resnlt of their retention from materials making np the diet of the organism, althongh the componnds may have snffered minor modifications to allow of their ntilization within the organism [17]. It shonld be noted that carotenoids in marine animals are almost always fonnd as protein complexes, and it is not possible to separate these by thin-layer methods withont prior treatment to remove or denatnre the protein. 

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