Self-Diffusion of End-Capped Oligo(ethylene glycol)s in Poly(vinyl alcohol) Aqueous Solutions and Gels

Masaro, L.; Zhu, X. X.

doi:10.1021/ma9902908

Cited by 17 publications

(25 citation statements)

References 48 publications

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“…Rayleigh interferometry has been suggested as a technique of superior accuracy, but requires macroscopic concentration gradients, which are not practical for many applications (Annunziata et al, 2005). Nuclear magnetic resonance microscopy (NMR) can measure diffusion of solutes in liquids or gels, but has limits related to spin-spin relaxation times, magnetic gradient strength and eddy currents, which could skew results (Massaro and Zhu, 1999). Further, NMR that allows studying solid samples also requires expensive and dedicated facilities not readily available to most investigators.…”

Section: Discussionmentioning

confidence: 99%

Predicting Drug Release From Degradable Hydrogels Using Fluorescence Correlation Spectroscopy and Mathematical Modeling

Sheth

Barnard

Hyatt

et al. 2019

Front. Bioeng. Biotechnol.

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Predicting release from degradable hydrogels is challenging but highly valuable in a multitude of applications such as drug delivery and tissue engineering. In this study, we developed a simple mathematical and computational model that accounts for time-varying diffusivity and geometry to predict solute release profiles from degradable hydrogels. Our approach was to use time snapshots of diffusivity and hydrogel geometry data measured experimentally as inputs to a computational model which predicts release profile. We used two model proteins of varying molecular weights: bovine serum albumin (BSA; 66 kDa) and immunoglobulin G (IgG; 150 kDa). We used fluorescence correlation spectroscopy (FCS) to determine protein diffusivity as a function of hydrogel degradation. We tracked changes in gel geometry over the same time period. Curve fits to the diffusivity and geometry data were used as inputs to the computational model to predict the protein release profiles from the degradable hydrogels. We validated the model using conventional bulk release experiments. Because we approached the hydrogel as a black box, the model is particularly valuable for hydrogel systems whose degradation mechanisms are not known or cannot be accurately modeled.

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Section: Discussionmentioning

confidence: 99%

Predicting Drug Release From Degradable Hydrogels Using Fluorescence Correlation Spectroscopy and Mathematical Modeling

Sheth

Barnard

Hyatt

et al. 2019

Front. Bioeng. Biotechnol.

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“…It is very important to bear in mind that the obstruction model principle presupposes that the protein network of the UF model cheese is "fixed." Moreover, this model does not take into account either solute-matrix interactions or the physicochemical properties of the solutes, which have been found to be significant in certain cases (Matsukawa and Ando, 1997;Masaro and Zhu, 1999b). We assumed there were no electrostatic interactions between the FITC-dextrans and the UF model cheese because these solutes are molecules with a neutral charge.…”

Section: Diffusion In the Model Cheesementioning

confidence: 99%

Transport phenomena in a model cheese: The influence of the charge and shape of solutes on diffusion

Silva

Peixoto

Lortal

et al. 2013

Journal of Dairy Science

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During cheese ripening, microorganisms grow as immobilized colonies, metabolizing substrates present in the matrix and generating products from enzymatic reactions. Local factors that limit the rates of diffusion, either within the general cheese matrix or near the colonies, may influence the metabolic activity of the bacteria during ripening, affecting the final quality of the cheese. The objective of this study was to determine the diffusion coefficients of solutes as a function of their different physicochemical characteristics (size, charge, and shape) in an ultrafiltrate (UF) model cheese (based on ultrafiltered milk) to enable better understanding of the ripening mechanisms. Diffusion coefficients of fluorescein isothiocyanate (FITC)-dextrans (4 kDa to 2 MDa) and FITC-labeled dairy proteins (α-lactalbumin, β-lactoglobulin, and BSA) were measured using the technique of fluorescence recovery after photobleaching (FRAP). This study showed that macromolecules up to 2 MDa and proteins could diffuse through the UF model cheese. The larger FITC-dextrans were not more hindered by the structure of the UF model cheese compared with the smaller ones. Any decrease in the diffusion coefficients of solutes was related only to their hydrodynamic radii. The FITC-dextran diffusion data were fitted to an obstruction model, resulting in a constant obstruction factor (k ~0.42). Diffusion in the model cheese was sensitive to the physicochemical characteristics of the solute. The FITC-dairy proteins studied (rigid and negatively charged molecules) were hindered to a greater degree than the FITC-dextrans (flexible and charge-neutral molecules) in the UF model cheese. The existence of steric and electrostatic interactions between the protein matrix of the UF model cheese and the FITC-dairy proteins could explain the decrease in diffusion compared with FITC-dextrans.

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“…Drug diffusion in porous hydrogels is significant for understanding the transport process in organisms [1][2][3] and the release from specific sustained-release dosage forms, such as hydrophilic matrix tablets 4,5 and sustained delivery implants. [6][7][8] Agarose, a polysaccharide consisting of 1,3-linked D-galactopyranose and 1,4-linked 3,6-anhydro-R-L-galactopyranose, 9 can form a physically crosslinked hydrogel by cooling a hot agarose aqueous solution.…”

Section: Introductionmentioning

confidence: 99%

Diffusion of levofloxacin mesylate in agarose hydrogels monitored by a refractive‐index method

Dai

Wang

et al. 2011

J of Applied Polymer Sci

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The diffusion of levofloxacin mesylate (MSALVFX) within agarose hydrogels was investigated by an improved refractive-index method. The diffusion coefficient of MSALVFX in infinite dilution (D 0 ) was obtained as 4.01 Â 10 À6 cm 2 /s (25 C) through extrapolation according to Kohlrausch's law. The diffusion behavior of MSALVFX under conditions of different solute concentrations, polymer volume fractions, and temperatures was studied in detail. In the considered range of agarose concentrations (0.5-2.5%, w/w), the ratio of D g to D 0 (where D g is the effective diffusion coefficient of MSALVFX in the agarose hydrogel) decreased from 0.938 to 0.835 because of the retardance effect of agarose fiber. Furthermore, the experimental data were analyzed with the Amsden, Clague and Philips, and Ogston models, and the data fit the Amsden model best.

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Self-Diffusion of End-Capped Oligo(ethylene glycol)s in Poly(vinyl alcohol) Aqueous Solutions and Gels

Cited by 17 publications

References 48 publications

Predicting Drug Release From Degradable Hydrogels Using Fluorescence Correlation Spectroscopy and Mathematical Modeling

Predicting Drug Release From Degradable Hydrogels Using Fluorescence Correlation Spectroscopy and Mathematical Modeling

Transport phenomena in a model cheese: The influence of the charge and shape of solutes on diffusion

Diffusion of levofloxacin mesylate in agarose hydrogels monitored by a refractive‐index method

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