Thermodynamic modeling of the dissociation conditions of hydrogen sulfide clathrate hydrate in the presence of aqueous solution of inhibitor (alcohol, salt or ethylene glycol)

2014 ◽  
Vol 92 (11) ◽  
pp. 2283-2293 ◽  
Author(s):  
Abolfazl Mohammadi ◽  
Mehrdad Manteghian ◽  
Amir H. Mohammadi ◽  
Arash Kamran-Pirzaman
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Sulfide ◽  
Ethylene Glycol ◽  
Thermodynamic Modeling ◽  
Clathrate Hydrate

Immuno-compatibility of desaminotyrosine and desaminotyrosyl tyrosine functionalized star-shaped oligo(ethylene glycol)s with different molecular weights

2015 ◽  
Vol 1718 ◽  
pp. 97-102 ◽  
Author(s):  
Toralf Roch ◽  
Konstanze K. Julich-Gruner ◽  
Axel T. Neffe ◽  
Nan Ma ◽  
Andreas Lendlein
Keyword(s):  
Aqueous Solution ◽  
Ethylene Glycol ◽  
Average Molecular Weight ◽  
Molecular Weights ◽  
Immunological Effects ◽  
Microbial Products ◽  
Low Levels ◽  
Chain Lengths ◽  
Immunological Evaluation

ABSTRACTPolymer-based therapeutic strategies require biomaterials with properties and functions tailored to the demands of specific applications leading to an increasing number of newly designed polymers. For the evaluation of those new materials, comprehensive biocompatibility studies including cyto-, tissue-, and immunocompatibility are essential. Recently, it could be demonstrated that star-shaped amino oligo(ethylene glycol)s (sOEG) with a number average molecular weight of 5 kDa and functionalized with the phenol-derived moieties desaminotyrosine (DAT) or desaminotyrosyl tyrosine (DATT) behave in aqueous solution like surfactants without inducing a substantial cytotoxicity, which may qualify them as solubilizer for hydrophobic drugs in aqueous solution. However, for biomedical applications the polymer solutions need to be free of immunogenic contaminations, which could result from inadequate laboratory environment or contaminated starting material. Furthermore, the materials should not induce uncontrolled or undesired immunological effects arising from material intrinsic properties. Therefore, a comprehensive immunological evaluation as perquisite for application of each biomaterial batch is required. This study investigated the immunological properties of sOEG-DAT(T) solutions, which were prepared using sOEG with number average molecular weights of 5 kDa, 10 kDa, and 20 kDa allowing analyzing the influence of the sOEG chain lengths on innate immune mechanisms. A macrophage-based assay was used to first demonstrate that all DAT(T)-sOEG solutions are free of endotoxins and other microbial contaminations such as fungal products. In the next step, the capacity of the different DAT(T)-functionalized sOEG solutions to induce cytokine secretion and generation of reactive oxygen species (ROS) was investigated using whole human blood. It was observed that low levels of the pro-inflammatory cytokines interleukin(IL)-1β and IL-6 were detected for all sOEG solutions but only when used at concentrations above 250 µg·mL-1. Furthermore, only the 20 kDa sOEG-DAT induced low amounts of ROS-producing monocytes. Conclusively, the data indicate that the materials were not contaminated with microbial products and do not induce substantial immunological adverse effectsin vitro,which is a prerequisite for future biological applications.

scholarly journals Adsorption of cesium from aqueous solution using agricultural residue – Walnut shell: Equilibrium, kinetic and thermodynamic modeling studies

2013 ◽  
Vol 47 (7) ◽  
pp. 2563-2571 ◽  
Author(s):  
Dahu Ding ◽  
Yingxin Zhao ◽  
Shengjiong Yang ◽  
Wansheng Shi ◽  
Zhenya Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Thermodynamic Modeling ◽  
Walnut Shell ◽  
Agricultural Residue ◽  
Modeling Studies
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