Nutrient transport limitation remains a fundamental issue for in vitro culture of engineered tissues. In this study, perfusion bioreactor configurations were investigated to provide uniform delivery of oxygen to media equivalents (MEs) being developed as the basis for tissue-engineered arteries. Bioreactor configurations were developed to evaluate oxygen delivery associated with complete transmural flow (through the wall of the ME), complete axial flow (through the lumen), and a combination of these flows. In addition, transport models of the different flow configurations were analyzed to determine the most uniform oxygen profile throughout the tissue, incorporating direct measurements of tissue hydraulic conductivity, cellular O(2) consumption kinetics, and cell density along with ME physical dimensions. Model results indicate that dissolved oxygen (DO) uniformity is improved when a combination of transmural and axial flow is implemented; however, detrimental effects could occur due to lumenal pressure exceeding the burst pressure or damaging interstitial shear stress imparted by excessive transmural flow rates or decreasing hydraulic conductivity due to ME compaction. The model was verified by comparing predicted with measured outlet DO concentrations. Based on these results, the combination of a controlled transmural flow coupled with axial flow presents an attractive means to increase the transport of nutrients to cells within the cultured tissue to improve growth (increased cell and extracellular matrix concentrations) as well as uniformity.
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http://dx.doi.org/10.1002/bit.22475 | DOI Listing |
J Korean Med Sci
January 2025
Division of Cardiology, Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
Background: The ionic mechanism underlying Brugada syndrome (BrS) arises from an imbalance in transient outward current flow between the epicardium and endocardium. Previous studies report that artemisinin, originally derived from a Chinese herb for antimalarial use, inhibits the Ito current in canines. In a prior study, we showed the antiarrhythmic effects of artemisinin in BrS wedge preparation models.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Civil and Environmental Engineering, University of Florence, Via di S. Marta, 3, Florence, 50139, Italy.
Mathematical and physical modeling of flows in collapsible pipes often relates the flow area to the difference between the internal and the external pressures (i.e. the transmural pressure).
View Article and Find Full Text PDFCirc Cardiovasc Interv
December 2024
Cardiovascular Translational Laboratory, Providence Research and Centre for Heart Lung Innovation, Vancouver, British Columbia, Canada (J.Y., H.G., J.J., A.L., J.G.W., J.S., D.M., S.L.S.).
Background: Transcatheter aortic valve replacement (TAVR) pushes aside the diseased native aortic valve and creates a native neo-sinus bordered by the aortic root wall and the displaced native valve. There are limited data on the progression of native valve disease post-TAVR and no previous analysis of the native neo-sinus.
Methods: Native aortic valves and native neo-sinus explants obtained post-TAVR were evaluated histologically (hematoxylin and eosin, Movat pentachrome, and Martius Scarlet Blue stains) and by immunohistochemistry (TGF-β1 [transforming growth factor-beta 1], FAP [fibroblast activation protein], and ALP [alkaline phosphatase]) to assess disease mechanisms.
J Cardiovasc Magn Reson
December 2024
Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China; Clinical Research Center for Medical Imaging in Hunan Province, Changsha, China. Electronic address:
Background: Cardiac involvement in light chain (AL) amyloidosis is the main determinant of prognosis. Amyloid can be deposited in the extracellular space and cause an increase in extracellular volume (ECV). At the same time, amyloid can also be deposited in the wall of small vessels and cause microvascular dysfunction.
View Article and Find Full Text PDFAm J Hypertens
November 2024
Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York, USA.
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