Diffusion of solutes in agarose and alginate gels: 1H and 23Na PFGSE and 23Na TQF NMR studies

Lundberg, Peter; Kuchel, Philip W.

doi:10.1002/mrm.1910370108

Cited by 49 publications

(25 citation statements)

References 47 publications

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“…In previous computational studies, concentration profiles within constructs have been computed on the basis of values in the surrounding medium (10,(21)(22)(23)(24). Except in the study by Malda (22), computed solute concentration profiles have not been confirmed by direct experimental measurement.…”

Section: Discussionmentioning

confidence: 99%

“…Also the fluid flow in combination with oxygen mass transfer to and within TE constructs has been modeled in a concentric cylinder bioreactor (12). At the construct level nutrient diffusion, oxygen uptake, matrix biosynthesis, and cell growth within TE cartilage constructs have been modeled (10,(21)(22)(23)(24). The largest source of uncertainty in modeling studies, however, is associated with the cell behavior, both qualitatively and quantitatively.…”

Section: Introductionmentioning

confidence: 99%

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Computational Study of Culture Conditions and Nutrient Supply in Cartilage Tissue Engineering

Sengers

Donkelaar

Oomens

et al. 2008

Biotechnol Progress

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Different culture conditions for cartilage tissue engineering were evaluated with respect to the supply of oxygen and glucose and the accumulation of lactate. A computational approach was adopted in which the culture configurations were modeled as a batch process and transport was considered within constructs seeded at high cell concentrations and of clinically relevant dimensions. To assess the extent to which mass transfer can be influenced theoretically, extreme cases were distinguished in which the culture medium surrounding the construct was assumed either completely static or well mixed and fully oxygenated. It can be concluded that severe oxygen depletion and lactate accumulation can occur within constructs for cartilage tissue engineering. However, the results also indicate that transport restrictions are not insurmountable, providing that the medium is well homogenized and oxygenated and the construct's surfaces are sufficiently exposed to the medium. The large variation in uptake rates of chondrocytes indicates that for any specific application the quantification of cellular utilization rates, depending on the cell source and culture conditions, is an essential starting point for optimizing culture protocols.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Computational Study of Culture Conditions and Nutrient Supply in Cartilage Tissue Engineering

Sengers

Donkelaar

Oomens

et al. 2008

Biotechnol Progress

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“…Diffusion-based techniques can separate the sodium signal from the intra-cellular and extra-cellular compartments based on the differences between the motional properties of the ions in these two compartments [78–80]. The fast relaxation rates and the low gyromagnetic ratio of sodium require the use of very large magnetic field gradients and fast switching, which is challenging but not impossible in clinical MRI scanners.…”

Section: Pulse Sequences For Compartment and Fluid Suppressionmentioning

confidence: 99%

Sodium MRI: Methods and applications

Madelin

Lee

Regatte

et al. 2014

Progress in Nuclear Magnetic Resonance Spectroscopy

187

209

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Sodium NMR spectroscopy and MRI have become popular in recent years through the increased availability of high-field MRI scanners, advanced scanner hardware and improved methodology. Sodium MRI is being evaluated for stroke and tumor detection, for breast cancer studies, and for the assessment of osteoarthritis and muscle and kidney functions, to name just a few. In this article, we aim to present an up-to-date review of the theoretical background, the methodology, the challenges and limitations, and current and potential new applications of sodium MRI.

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“…This biexponential relaxation behavior allows the creation and detection of multiple quantum coherences (9,10). MQF NMR spectroscopy of quadrupolar I ϭ 3 2 alkali metal nuclei has been studied extensively in macromolecular model systems (11)(12)(13)(14)(15) and in perfused organs, such as rat salivary glands (16), rat and guinea-pig hearts (17)(18)(19)(20)(21)(22), and rat liver (23). It was also applied to in vivo organs, such as rat liver (24), human brain, and skeletal muscle (25).…”

Section: Introductionmentioning

confidence: 99%

Competition between Na+ and Li+ for Unsealed and Cytoskeleton-Depleted Human Red Blood Cell Membrane: A 23Na Multiple Quantum Filtered and 7Li NMR Relaxation Study

Srinivasan

Minadeo

Toon

et al. 1999

Journal of Magnetic Resonance

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Evidence for competition between Li(+) and Na(+) for binding sites of human unsealed and cytoskeleton-depleted human red blood cell (csdRBC) membranes was obtained from the effect of added Li(+) upon the (23)Na double quantum filtered (DQF) and triple quantum filtered (TQF) NMR signals of Na(+)-containing red blood cell (RBC) membrane suspensions. We found that, at low ionic strength, the observed quenching effect of Li(+) on the (23)Na TQF and DQF signal intensity probed Li(+)/Na(+) competition for isotropic binding sites only. Membrane cytoskeleton depletion significantly decreased the isotropic signal intensity, strongly affecting the binding of Na(+) to isotropic membrane sites, but had no effect on Li(+)/Na(+) competition for those sites. Through the observed (23)Na DQF NMR spectra, which allow probing of both isotropic and anisotropic Na(+) motion, we found anisotropic membrane binding sites for Na(+) when the total ionic strength was higher than 40 mM. This is a consequence of ionic strength effects on the conformation of the cytoskeleton, in particular on the dimer-tetramer equilibrium of spectrin. The determinant involvement of the cytoskeleton in the anisotropy of Na(+) motion at the membrane surface was demonstrated by the isotropy of the DQF spectra of csdRBC membranes even at high ionic strength. Li(+) addition initially quenched the isotropic signal the most, indicating preferential Li(+)/Na(+) competition for the isotropic membrane sites. High ionic strength also increased the intensity of the anisotropic signal, due to its effect on the restructuring of the membrane cytoskeleton. Further Li(+) addition competed with Na(+) for those sites, quenching the anisotropic signal. (7)Li T(1) relaxation data for Li(+)-containing suspensions of unsealed and csdRBC membranes, in the absence and presence of Na(+) at low ionic strength, showed that cytoskeleton depletion does not affect the affinity of Na(+) for the RBC membrane, but increases the affinity of Li(+) by 50%. This clearly indicates that cytoskeleton depletion favors Li(+) relative to Na(+) binding, and thus Li(+)/Na(+) competition for its isotropic sites. Thus, this relaxation technique proves to be very sensitive to alkali metal binding to the membrane, detecting a more pronounced steric hindrance effect of the cytoskeleton network to binding of the larger hydrated Li(+) ion to the membrane phosphate groups.

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Diffusion of solutes in agarose and alginate gels: ¹H and ²³Na PFGSE and ²³Na TQF NMR studies

Cited by 49 publications

References 47 publications

Computational Study of Culture Conditions and Nutrient Supply in Cartilage Tissue Engineering

Computational Study of Culture Conditions and Nutrient Supply in Cartilage Tissue Engineering

Sodium MRI: Methods and applications

Competition between Na+ and Li+ for Unsealed and Cytoskeleton-Depleted Human Red Blood Cell Membrane: A 23Na Multiple Quantum Filtered and 7Li NMR Relaxation Study

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