Salt leaching

The PGS obtained by Wang and coworkers was a kind of thermoset elastomer with the Young s modulus of 0.282 0.025 MPa, a tensile strain of at least 267 zE 59.4%, and a tensUe strength was at least 0.5 MPa. The mechanical properties of PGS were well consisted with that of some common soft tissues. Although PGS is a thermoset polymer, its prepolymer can be processed into various shapes by solving it in common organic solvents such as 1,3-dioxolane, tetrahydrofuran, isopropanol, ethanol, and iV,M-dimethylformamide. Porous scaffolds can be fabricated by salt leaching. 

The cylindrical porous scaffolds based on TMC-DLLA copolymers were prepared by salt-leaching method. Two-ply porous nerve guides were prepared by a combination of dip-coating (inner layer) and fiber-winding (outer layer) techniques. 

Stock et al. used P4HB scaffolds and tissue engineered the patch with a porosity of 95% and pore sizes in the range of 180-240 p,m by salt-leaching and solvent evaporation. The sheep autologous cells (endothelial, smooth muscle, and fibroblast cells) were seeded on the scaffold before implantation. Results confirmed that the cell-seeded implants induced progressive tissue regeneration with no thrombus formation, stenosis, or dilatation. 

In order to obtain information about the exchange processes between the basalt and the salt, leaching experiments were performed with 1.5 m HC1 on basalt powder samples that had previously been washed in bi-distilled water in order to remove salt minerals. The H20-washed whole rock samples, as well as the resulting leachate and residue fractions have been analysed for major elements, REE, and for Sr isotopes. 

Potassium does not occur in nature in tlie free state because of its great chemical reactivity. The major basic potash chemical used as a source of potassium is potassium chloride, KC1. The potassium content of all potash sources generally is given in terms of the oxide K2O. The majority of potash produced comes from mineral deposits that were formed by llie evaporation of prehistoric lakes and seas which had become enriched in potassium salts leached from the soil, In addition ro natural deposits of potassium salts, large concentrations of potassium also are found in some bodies of water, including the Great Salt Lake and the Salduro Marsh in Utah, the Dead Sea between Israel and Jordan, and Searles Lake in California. All of these brines are used for the commercial production of potash. 

A farmer wants to reclaim a soil contaminated with 200 mmol L 1 NaCl. He/she needs advice on how to do it. List the type of tests you would recommend and the reasons for each of the tests and outline the salt-leaching procedure,... 

On the other hand, there was not a detectable salt leaching during the reaction, neither tungsten nor aluminium or copper were detected in the final solution by atomic absorption spectrometry. Also, an additional test was performed. Alter refluxing in anisole the AITPApva-peg catalyst, it was filtered. Tungsten, aluminum or copper were not detected in the solution, and any conversion was observed after acetic anhydride addition at reaction temperature. 

Scaffolds can be fabricated by using different types of methodologies such as fiber bonding, salt leaching, gas-induced foaming, phase separation, electrospinning, solid freeform fabrication, and molecular self assembly [15, 17]. Some of the fabrication techniques are discussed below. 

Tessmar JKV, Holland TA, Mikos AG (2006) Salt leaching for polymer scaffolds laboratory-scale manufacture of cell carriers. In Ma PX, Elisseeff J (eds) Scaffolding in tissue engineering. CRC, Boca Raton... 

The most widespread methods to manufacture the PHB scaffolds for tissue engineering by means of improvement of cell adhesion and growth on polymer surface are change of PHB surface properties and microstructure by salt-leaching methods and enzymatic/chemical/physical treatment of polymer surface [40, 89, 98, 113]. Adhesion to polymer substrates is one of the key issues in tissue engineering because adhesive interactions control cell physiology. One of the most effective techniques to improve adhesion and growth of cells on PHB films is the treatment of polymer surface with enzymes, alkali, or low-pressure plasma [40, 113]. Lipase treatment increases the viable cell number on the PHB film from 100 to 200 times compared to the untreated PHB film. NaOH treatment on PHB... 

Yoon, J. J., Song, S. H., Lee, D. S., Park, T. G. Immohilization of cell adhesive RGD peptide onto the surface of highly porous biodegradable polymer scaffolds fabricated by a gas foaming/salt leaching method. Biomaterials. 2004, 25, 5613-5620. 

Faezah and co-workers [22] reported an enzymatic degradation study comparing solvent-cast film and salt-leached film. The PhaZ enzyme in this study was obtained from Acidovorax sp. It was reported that the enzymatic degradability of the salt-leached film was higher than... 

Heparin-conjugated PLGA scaffolds have been fabricated though techniques such as gas-foaming/salt-leaching and have been used to sustain drug delivery of growth factors like BMP-2 to enhance bone formation [92,93]. 

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