Effect of Initial Seeding Density on Cell Behavior-Driven Epigenetic Memory and Preferential Lineage Differentiation of Human iPSCs

2021 ◽  
Author(s):  
Mee-Hae Kim ◽  
Naruchit Thanuthanakhun ◽  
Shun Fujimoto ◽  
Masahiro Kino-oka
Keyword(s):  
Seeding Density ◽  
Cell Behavior ◽  
Epigenetic Memory ◽  
Lineage Differentiation ◽  
Human Ipscs ◽  
Initial Seeding ◽  
Initial Seeding Density

scholarly journals Effect of initial seeding density on cell behavior-driven epigenetic memory and preferential lineage differentiation of human iPSCs

2021 ◽  
Vol 56 ◽  
pp. 102534
Author(s):  
Mee-Hae Kim ◽  
Naruchit Thanuthanakhun ◽  
Shun Fujimoto ◽  
Masahiro Kino-oka
Keyword(s):  
Seeding Density ◽  
Cell Behavior ◽  
Epigenetic Memory ◽  
Lineage Differentiation ◽  
Human Ipscs ◽  
Initial Seeding ◽  
Initial Seeding Density

scholarly journals Denitrifying bacteria respond to and shape microscale gradients within particulate matrices

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Steven Smriga ◽  
Davide Ciccarese ◽  
Andrew R. Babbin
Keyword(s):  
Spatial Arrangement ◽  
Bulk Water ◽  
Seeding Density ◽  
Anaerobic Processes ◽  
Direct Association ◽  
Denitrification Activity ◽  
Nitrate And Nitrite ◽  
Aerobic And Anaerobic ◽  
Initial Seeding ◽  
Initial Seeding Density

AbstractHeterotrophic denitrification enables facultative anaerobes to continue growing even when limited by oxygen (O2) availability. Particles in particular provide physical matrices characterized by reduced O2 permeability even in well-oxygenated bulk conditions, creating microenvironments where microbial denitrifiers may proliferate. Whereas numerical particle models generally describe denitrification as a function of radius, here we provide evidence for heterogeneity of intraparticle denitrification activity due to local interactions within and among microcolonies. Pseudomonas aeruginosa cells and microcolonies act to metabolically shade each other, fostering anaerobic processes just microns from O2-saturated bulk water. Even within well-oxygenated fluid, suboxia and denitrification reproducibly developed and migrated along sharp 10 to 100 µm gradients, driven by the balance of oxidant diffusion and local respiration. Moreover, metabolic differentiation among densely packed cells is dictated by the diffusional supply of O2, leading to distinct bimodality in the distribution of nitrate and nitrite reductase expression. The initial seeding density controls the speed at which anoxia develops, and even particles seeded with few bacteria remain capable of becoming anoxic. Our empirical results capture the dynamics of denitrifier gene expression in direct association with O2 concentrations over microscale physical matrices, providing observations of the co-occurrence and spatial arrangement of aerobic and anaerobic processes.

scholarly journals Effects of Initial Seeding Density and Fluid Perfusion Rate on Formation of Tissue-Engineered Bone

2008 ◽  
Vol 14 (11) ◽  
pp. 1809-1820 ◽  
Author(s):  
Warren L. Grayson ◽  
Sarindr Bhumiratana ◽  
Christopher Cannizzaro ◽  
P.-H. Grace Chao ◽  
Donald P. Lennon ◽  
...  
Keyword(s):  
Seeding Density ◽  
Perfusion Rate ◽  
Initial Seeding ◽  
Initial Seeding Density

scholarly journals Effect of Initial Seeding Density on Human Umbilical Cord Mesenchymal Stromal Cells for Fibrocartilage Tissue Engineering

2009 ◽  
Vol 15 (5) ◽  
pp. 1009-1017 ◽  
Author(s):  
Limin Wang ◽  
Kiran Seshareddy ◽  
Mark L. Weiss ◽  
Michael S. Detamore
Keyword(s):  
Tissue Engineering ◽  
Umbilical Cord ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Seeding Density ◽  
Human Umbilical Cord ◽  
Initial Seeding ◽  
Initial Seeding Density

scholarly journals Effect ofEx VivoCulture Conditions on Immunosuppression by Human Mesenchymal Stem Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Myoung Woo Lee ◽  
Dae Seong Kim ◽  
Somi Ryu ◽  
In Keun Jang ◽  
Hye Jin Kim ◽  
...  
Keyword(s):  
Gene Expression ◽  
Ex Vivo ◽  
Expression Profiles ◽  
Human Mesenchymal Stem Cells ◽  
Gene Expression Profiles ◽  
Culture Conditions ◽  
Seeding Density ◽  
Initial Seeding ◽  
Density Treatment

A microarray analysis was performed to investigate whetherex vivoculture conditions affect the characteristics of MSCs. Gene expression profiles were mainly influenced by the level of cell confluence rather than initial seeding density. The analysis showed that 276 genes were upregulated and 230 genes downregulated in MSCs harvested at~90% versus~50% confluence (P<0.05,FC>2). The genes that were highly expressed in MSCs largely corresponded to chemotaxis, inflammation, and immune responses, indicating direct or indirect involvement in immunomodulatory functions. Specifically, PTGES and ULBP1 were up-regulated in MSCs harvested at high density. Treatment of MSCs withPTGESorULBP1siRNA reversed their inhibition of T-cell proliferationin vitro. The culture conditions such as cell confluence at harvest seem to be important for gene expression profile of MSCs; therefore, the results of this study may provide useful guidelines for the harvest of MSCs that can appropriately suppress the immune response.

The Effect of Cell Behavior on Apatites with Different Fluorine Contents

2005 ◽  
Vol 284-286 ◽  
pp. 577-580
Author(s):  
Hai Bo Qu ◽  
Rachel J. Waugh O'Neill ◽  
Mei Wei
Keyword(s):  
Cell Attachment ◽  
Early Stage ◽  
Environmental Scanning Electron Microscopy ◽  
Fluorine Content ◽  
Seeding Density ◽  
Cell Behavior ◽  
Environmental Scanning ◽  
Osteosarcoma Cells ◽  
Tissue Culture Polystyrene ◽  
Scanning Electron

Fluoridated hydroxyapatite (FHA) discs with various fluorine contents have been used to study the effect of fluorine content on early-stage cell behavior. FHA powders with fluorine content in the range 0-0.577 (mol F /mol apatite) were pressed into discs and sintered at 1200°C for 1 hour. SAOs-2 rat osteosarcoma cells were cultured on each FHA disc and tissue culture polystyrene (control) with the same seeding density for 4 hours. The cell count was conducted using Alamarblue, and the morphology of cell attachment was observed using environmental scanning electron microscopy. It was apparent that the fluorine content in FHA had significant impact on the early cell behavior.

Interactions of Microcarriers in Simulated Microgravity

1999 ◽  
Author(s):  
David F. Meaney ◽  
Eric D. Johnston ◽  
Mitchell Litt ◽  
Solomon R. Pollack
Keyword(s):  
Simulated Microgravity ◽  
Particle Distribution ◽  
Particle Density ◽  
Particle Collision ◽  
Microgravity Environment ◽  
Seeding Density ◽  
Particle Interactions ◽  
Multiple Particles ◽  
Surrounding Fluid ◽  
Initial Seeding

Abstract In this study, we developed a numerical model that simulated the simultaneous motion of several microcarriers in the simulated microgravity environment of the NASA HARV bioreactor. Simulations were used to predict the interaction and collision of these multiple particles under different initial seeding densities. In addition, the quasi-steady particle distribution for beads which are lighter than the surrounding fluid is presented. Results show that the frequency of particle collision increases significantly only when the initial seeding density is close to the maximum density. In addition, a stable particle density, with a relatively constant number of particle interactions, is achieved with all seeding densities using beads that are lighter than the surrounding fluid. These results are similar to those measured experimentally for light beads — beads co-locate within a sub-region of the HARV bioreactor, and achieve a consistent final bead density that is independent of the starting seeding density.

Extracellular matrix: the gatekeeper of tumor angiogenesis

2019 ◽  
Vol 47 (5) ◽  
pp. 1543-1555 ◽  
Author(s):  
Maurizio Mongiat ◽  
Simone Buraschi ◽  
Eva Andreuzzi ◽  
Thomas Neill ◽  
Renato V. Iozzo
Keyword(s):  
Extracellular Matrix ◽  
Tumor Angiogenesis ◽  
Signaling Cascades ◽  
Cancer Growth ◽  
Cell Behavior ◽  
Metastatic Progression ◽  
Surface Receptors ◽  
The Matrix ◽  
Multiple Signaling

Abstract The extracellular matrix is a network of secreted macromolecules that provides a harmonious meshwork for the growth and homeostatic development of organisms. It conveys multiple signaling cascades affecting specific surface receptors that impact cell behavior. During cancer growth, this bioactive meshwork is remodeled and enriched in newly formed blood vessels, which provide nutrients and oxygen to the growing tumor cells. Remodeling of the tumor microenvironment leads to the formation of bioactive fragments that may have a distinct function from their parent molecules, and the balance among these factors directly influence cell viability and metastatic progression. Indeed, the matrix acts as a gatekeeper by regulating the access of cancer cells to nutrients. Here, we will critically evaluate the role of selected matrix constituents in regulating tumor angiogenesis and provide up-to-date information concerning their primary mechanisms of action.

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