Search for: biological-transport
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    Disc size markedly influences concentration profiles of intravenously administered solutes in the intervertebral disc: A computational study on glucosamine as a model solute

    , Article European Spine Journal ; Vol. 23, issue. 4 , April , 2014 , p. 715-723 Motaghinasab, S ; Shirazi-Adl, A ; Parnianpour, M ; Urban, J. P. G ; Sharif University of Technology
    Purpose: Tests on animals of different species with large differences in intervertebral disc size are commonly used to investigate the therapeutic efficacy of intravenously injected solutes in the disc. We hypothesize that disc size markedly affects outcome. Methods: Here, using a small non-metabolized molecule, glucosamine (GL) as a model solute, we calculate the influence of disc size on transport of GL into rat, rabbit, dog and human discs for 10 h post intravenous-injection. We used transient finite element models and considered an identical GL supply for all animals. Results: Huge effects of disc size on GL concentration profiles were found. Post-injection GL concentration in the rat... 

    Computational pharmacokinetics of solute penetration into human intervertebral discs-Effects of endplate permeability, solute molecular weight and disc size

    , Article Journal of Biomechanics ; Volume 45, Issue 13 , 2012 , Pages 2195-2202 ; 00219290 (ISSN) Motaghinasab, S ; Shirazi Adl, A ; Urban, J. P. G ; Parnianpour, M ; Sharif University of Technology
    A finite element model is developed to predict the penetration time-history of three different solutes into the human lumbar disc following intravenous injection. Antibiotics are routinely administered intravenously in spinal surgery to prevent disc infection. Successful prophylaxis requires antibiotics to reach adequate inhibitory levels. Here, the transient diffusion of cephazolin is investigated over 10. h post-injection in a human disc model subject to reported concentrations in the blood stream as the prescribed boundary sources. Post-injection variation of cephazolin concentrations in the disc adjacent to supply sources closely followed the decay curve in the blood stream and fell... 

    Theoretical modeling of actin-retrograde-flow passing clusters of confined T cell receptors

    , Article Mathematical Biosciences ; Volume 283 , 2017 , Pages 1-6 ; 00255564 (ISSN) Ghasemi V., A ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
    Elsevier Inc  2017
    Through the activation process of T cells, actin filaments move from the cell periphery toward the cell center. The moving filaments engage with T cell receptors and thus contribute to transportation of the signaling molecules. To study the connection between the moving actin filaments and T cell receptors, an experiment available in the literature has measured filaments flow velocity passing over a region of confined clusters of receptors. It shows that flow velocity decreases in the proximity of the receptors, and then regains its normal value after traversing the region, suggesting a dissipative friction-like connection. In this work, we develop a minimal theoretical model to re-examine... 

    Cell shape affects nanoparticle uptake and toxicity: An overlooked factor at the nanobio interfaces

    , Article Journal of Colloid and Interface Science ; Volume 531 , 2018 , Pages 245-252 ; 00219797 (ISSN) Farvadi, F ; Ghahremani, M. H ; Hashemi, F ; Hormozi Nezhad, M. R ; Raoufi, M ; Zanganeh, S ; Atyabi, F ; Dinarvand, R ; Mahmoudi, M ; Sharif University of Technology
    Academic Press Inc  2018
    Hypothesis: It is now being increasingly accepted that cells in their native tissue show different morphologies than those grown on a culture plate. Culturing cells on the conventional two-dimensional (2D) culture plates does not closely resemble the in vivo three-dimensional (3D) structure of cells which in turn seems to affect cellular function. This is one of the reasons, among many others, that nanoparticles uptake and toxicology data from 2D culture plates and in vivo environments are not correlated with one another. In this study, we offer a novel platform technology for producing more in vivo-like models of in vitro cell culture. Experiments: The normal fibroblast cells (HU02) were...