Coatings hydrophilic

Adsorbents for biomacromolecules such as proteins have special properties. First, they need to have large pore sizes. A ratio of pore radius to molecule radius larger than 5 is desirable to prevent excessive diffusional hindrance (see Intraparticle Mass Transfer in this section). Thus, for typical proteins, pore radii need to be in excess of 10-15 nm. Second, functional groups for interactions with the protein are usually attached to the adsorbent backbone via a spacer arm to provide accessibility. Third, adsorbents based on hydrophilic structures are preferred to limit nonspecific interactions with the adsorbent backbone and prevent global unfolding or denaturation of the protein. Thus, if hydrophobic supports are used, their surfaces are usually rendered hydrophilic by incorporating hydrophilic coatings such as dextran or polyvinyl alcohol. Finally, materials stable in sodium hydroxide solutions (used for clean-in-place) are... 

Once the durability testing of the fuel cells is finalized, the internal components are then characterized. For diffusion layers, some of these characterization techniques include SEM to visualize surface changes, porosimetry measurements to analyze any changes in porosity within the DL and MPL, IGC (inverse gas chromatography) to identify relative humidity effects on the hydrophobic properties of the DLs, contact angle measurements to observe any changes in the hydrophobic/hydrophilic coatings of the DL, etc. [254,255]. 

The choice of protein stabilizer stemmed from the necessity of burying the hybrid formulate in a water pool structured by a strongly hydrophilic coating shell. This appears to be an extremely efficient option allowing for... 

Fig. 16.14. Configuration of the M2 helices of the acetylcholine receptor in the closed and open states. The schematic representation is based on a comparison of the electron density map of the acetylcholine receptor in closed and open states. Only three of the five M2 helices are shown, a) Closed state the M2 helices are bent at the middle. The leucine residues point into the interior of the pore and prevent passage of ions, b) Open state the M2 helices are turned outwards at a tangent and the bulky leucine residues are removed from the center of the pore. Reorientation of the M2 helices causes a reorientation of polar amino adds that coat the interior of the pore. The polar amino acids (Ser and Thr residues) are oriented closer to the center of the pore and create a hydrophilic coating of the pore inner wall, which facilitates ion passage. According to Unwin,...

After an extensive review of possible new materials, the team found a material that had a surface-to-volume ratio closer to 1000 M /M and a void volume up to 98%. A hydrophilic coating could be grafted to its surface to provide a reservoir capacity to release nutrients in a controlled manner. Lastly, the hydrophilic coating could be copolymerized with certain bioactive polymers and ligands that improve cell adhesion dramatically. 

The matrices used in SEC are either polymeric or silica-based particles with a hydrophilic coating. The disadvantage of silica particles is that they tend to retain solutes by adsorption and may catalyze the degradation of solute molecules. To reduce adsorption, the surfaces of these particles are often modified by reaction with organic substituents. 

Sterically stabilized ( stealth ) liposomes, which carry hydrophilic coatings, are used to obtain prolonged circulation times. 

In common with other applications of photocatalysis (degradation of gas and solution phase pollutants, super hydrophilic coatings, metal recovery etc.), the material that has received the most attention in studies of heterogeneous pho-... 

Other Vinyl Derivatives. PVP is a nonionic surfactant used in 3% to 5% concentrations to increase viscosity of solutions. Although it exhibits surface-active properties similar to the cellulose ethers, PVP appears to have less abiUty to lower the interfacial tension at a water-oil interface. Nevertheless, in contrast to the cellulose ethers, PVP appears capable of forming hydrophilic coatings in the form of adsorbed layers. Because conjunctival mucin is believed to interact with the ocular surfece to form an adsorbing surface for aqueous tears, the formation by artificial means of a hydrophilic layer that would mimic conjimctival mucin (mucomimetic) appears to be clinically desirable. Both mucin- and aqueous-deficient dry eyes would benefit, because the wetting ability of the corneal surfece would be enhanced. 

Klein E, Eichhloz E, and Yeager DH. Affinity membranes prepared from hydrophilic coatings on microporous polysuffone hoUow fibers. J. Membr. Sci. 1994 90 68-80. 

Erythromycin, tylosin, L-lysin DEHPA Hydrophilic coating, hydrophilic support [15,181]... 

Epoxy coating is a hydrophilic coating due to the high content of ether and hydroxyl groups. It is expected that this hydrophilic surface will reduce protein adsorption and, thus, is suited for protein separations. 

BMP-2 is a recombinant protein which has the potential to develop into a biotech drug. Previous experiments with an uncoated capillary and a commercially available hydrophilic-coated column (Celect P150) failed to separate the BMP-2 components with repro-... 

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