Multilayer fluorescein

FIG. 9 Confocal laser scanning micrograph of a hollow polymer capsule. The polymer capsule was obtained from polymer multilayer-templated FDA microcrystals after removal of the colloidal core. The FDA microcrystals were coated with SDS and 11 polyelectrolyte layers [(PAH/PSS)3/PAH/ (PSS/PAH-FITC)2]. (PAH-FITC = PAH labeled with fluorescein isothiocyanate.) The microcrystal core was removed by exposure of the coated microcrystals to ethanol, causing solubilization of FDA. 

Fig. 14 Microfluidic array for a logarithmical perfusion device, (a) Photo of the four-channel device fllled with fluorescein. The chip has four loading outputs (gray arrows) and two input tubes (one for loading cells and one for perfusion black arrows), (b) Photo of multilayer 4x4 device fllled with fluorescein, (c) Gene expression during dynamic fluid flow versus no-flow fold-change values at 30 min (filled bars) and 1 h (open bars) post-flow [21]...

To describe the concentration profiles and release kinetics of fluorescein from single NP-shelled capsules, Munoz Tavera et al. solved a mathematical model that describes unsteady-state transport from multilayered spheres using the Sturm-Liouville approach [92], Several aspects of dye release, such as the asymptotic plateau effect of diffusive release and the effects of capsule diameter and shell thickness distribution on dye release, were captured by the model and confirmed by experimental data. 

FIGURE 56.12 Schematic (top row) and CLSM images illustrating permeation and encapsulation of urease-fluorescein isothiocyanate (FITC) into polyion multilayer capsules. Left, in water middle, in water/ethanol mixture 1 1 right, the capsule with encapsulated urease again in the water. (Reprinted with permission from Nano Lett., 1(3), Lvov, Y., Antipov, A., Mamedov, A., Mohwald, H., and Sukhorukov, G.B., Urease encapsulation in nanoorganized microshells, 125. Copyright 2001 American Chemical Society.)... 

Figure 15.4 The confocal images show the sequential formation of multilayered laminar flow in the micromixer. Bright layers (streams) are fluorescein solution.

The influence of water on the thickness of the multilayers is also well documented [112,321], Diffusion of radiolabeled salt ions has also been measured [126,315], Voltamperometry showed that PAH/PAA films had little effect on the diffusion of Fe(CN)6 , but that PAH/PSS films could hinder its transport [117], 6-carboxy-fluorescein [97], acridine orange [82], daunomycin [254], 2 -3 cyclic adenosine monophosphate [255], bisulfite [316], and different diazonium salts [148,316] have been shown to permeate deeply in multilayers built by ESA, Immunoglobulin G (IgG) could permeate or not in a superlattice made of anti-IgG layers and PAH/PSS spacer layers, depending on the thickness of the spacer layer. The diffusion constants of rhodamine and of 2,2,6,6,-tetramethyl-4-piperidinol-l-oxide (TEMPOL) in PAH/PSS multilayers have been quantified [114,115],... 

FIG. 4 Permeation and encapsulation of fluorescein isothiocyanate (FITC)-dextran (molecular weight 75,000) in polyelectrolyte multilayer capsules. (Left) pH 10, (center) pH 3, (right) pH increased to 10 after the capsules were loaded with FlTC-dextran at pH 3. The bulk FlTC-dextran was removed by washings at pH 10. (Top) scheme (bottom) confocal images of the capsules. 

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