Tissue Engineering
Shahryar Ramezani Bajgiran; Maryam Saadatmand
Volume 11, Issue 3 , September 2017, , Pages 211-218
Abstract
Despite the advancements made in the tissue engineering, one of the obstacles in producing thick tissues is the means of oxygen transport to the deep layered cells of the engineered tissue and creating the network of veins inside the tissue. One way to overcome this problem is to create a microfluidic ...
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Despite the advancements made in the tissue engineering, one of the obstacles in producing thick tissues is the means of oxygen transport to the deep layered cells of the engineered tissue and creating the network of veins inside the tissue. One way to overcome this problem is to create a microfluidic network of channels inside the porous scaffold. These channels can both enhance the oxygenation and produce a mold for the natural vessels created by the angiogenesis cells. In this paper the dissolved oxygen distribution inside a 2D scaffold, which contains bifurcation based microfluidic channels, has been simulated by the means of computational fluid dynamics. To achieve this, the liquid flow and oxygen transport equations have been solved with considerations to the boundary conditions and suitable parameters. The oxygen transport has been found for the static scaffold, and the scaffolds made from the 0 order to third order of bifurcation with a bifurcation angle of 45 degrees. The results have shown that the scaffold with the second order of bifurcation has a better oxygen distribution and also more free area for the cell proliferation, which is consistent with the references. Next, the bifurcation angle was reduced to 35 degrees for the second order scaffold which resulted in an increase in the non-hypoxic area. Generally, by designing optimized angle of bifurcation based channels, a significant area can be oxygenated, while there will be sufficient surface available for cell proliferations.
Tissue Engineering
Fateme Shamsi; Mohsen Janmaleki; Nasser Fatouraee
Volume 3, Issue 4 , June 2009, , Pages 265-274
Abstract
In this study a mechanism was modeled to control the jet path of nanofibers produced by electrospinning through inducing a magnetic field over the jet path. Firstly, a model was developed for the jet path in which the fibers composed of a series of viscoelastic segments. Considering the mass and momentum ...
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In this study a mechanism was modeled to control the jet path of nanofibers produced by electrospinning through inducing a magnetic field over the jet path. Firstly, a model was developed for the jet path in which the fibers composed of a series of viscoelastic segments. Considering the mass and momentum conservation and maxwellian model of stretching viscoelastic segments using three equations governing the jet dynamics of the jet model in electrospinning, a program was developed in MATLAB with Runge–Kutta method. After ensuring the accuracy of the model, its behavior was evaluated in the presence of a magnetic field. The field induced a uniform force distribution over the jet. As the intensity of the magnetic field increased; the instability and bending radius of the jet reduced. The results of the research showed that utilizing a suitable mechanism for applying magnetic field can provide help in controlling the jet path and alignment of the nanofibers.
Tissue Engineering
Mohsen Rabbani; Mohammad Tafazzoli Shadpour; Zahra Goli Malekabadi; Mohsen Janmaleki; Mohammad Taghi Khorasani; Mohammad Ali Shokrgozar
Volume 3, Issue 4 , June 2009, , Pages 307-314
Abstract
Vital function of the cell is correlated with the mechanical loads that the cell experiences. The cell shape and morphology are also related to its mechanical environments. Different methods have been proposed to obtain cell groups with the same morphology and alignment which considered desirable features ...
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Vital function of the cell is correlated with the mechanical loads that the cell experiences. The cell shape and morphology are also related to its mechanical environments. Different methods have been proposed to obtain cell groups with the same morphology and alignment which considered desirable features in tissue engineering applications. For instance, applying cyclic loading makes cells elongated and aligned as bundles in a specific direction to the tension axis. Applying static stretches also affect the cells morphology, extra-cellular matrix, enzymes secretion and genes expression. The effect of applying in vivo static stretch on cellular alignment was evaluated in this study. Human mesenchymal stem cells (hMSCs) were cultured on the elastic membrane, and then subjected to static stretch. The results demonstrated that applying a 10% static stretch for 24 hours aligns intra-structure actin filaments and applying a 20% static stretch had a significant effect on the arrangement of the oriented fibers.
