scholarly journals Open-Porous Hydroxyapatite Scaffolds for Three-Dimensional Culture of Human Adult Liver Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Anthony Finoli ◽  
Eva Schmelzer ◽  
Patrick Over ◽  
Ian Nettleship ◽  
Joerg C. Gerlach
Keyword(s):  
Gene Expression ◽  
Extracellular Matrix ◽  
Liver Cell ◽  
Matrix Protein ◽  
Three Dimensional ◽  
Liver Cells ◽  
Cytokeratin 19 ◽  
Porous Hydroxyapatite ◽  
Extracorporeal Liver Support ◽  
Three Dimensional Culture

Liver cell culture within three-dimensional structures provides an improved culture system for various applications in basic research, pharmacological screening, and implantable or extracorporeal liver support. Biodegradable calcium-based scaffolds in such systems could enhance liver cell functionality by providing endothelial and hepatic cell support through locally elevated calcium levels, increased surface area for cell attachment, and allowing three-dimensional tissue restructuring. Open-porous hydroxyapatite scaffolds were fabricated and seeded with primary adult human liver cells, which were embedded within or without gels of extracellular matrix protein collagen-1 or hyaluronan. Metabolic functions were assessed after 5, 15, and 28 days. Longer-term cultures exhibited highest cell numbers and liver specific gene expression when cultured on hydroxyapatite scaffolds in collagen-1. Endothelial gene expression was induced in cells cultured on scaffolds without extracellular matrix proteins. Hydroxyapatite induced gene expression for cytokeratin-19 when cells were cultured in collagen-1 gel while culture in hyaluronan increased cytokeratin-19 gene expression independent of the use of scaffold in long-term culture. The implementation of hydroxyapatite composites with extracellular matrices affected liver cell cultures and cell differentiation depending on the type of matrix protein and the presence of a scaffold. The hydroxyapatite scaffolds enable scale-up of hepatic three-dimensional culture models for regenerative medicine applications.

scholarly journals Effect of chondroitin sulfate and hyaluronic acid on gene expression in a three-dimensional culture of chondrocytes

2005 ◽  
Vol 100 (1) ◽  
pp. 123-126 ◽  
Author(s):  
Shohei Nishimoto ◽  
Mutsumi Takagi ◽  
Shigeyuki Wakitani ◽  
Takuya Nihira ◽  
Toshiomi Yoshida
Keyword(s):  
Gene Expression ◽  
Hyaluronic Acid ◽  
Chondroitin Sulfate ◽  
Three Dimensional ◽  
Three Dimensional Culture

scholarly journals Spheroidal aggregate culture of rat liver cells: histotypic reorganization, biomatrix deposition, and maintenance of functional activities.

1985 ◽  
Vol 101 (3) ◽  
pp. 914-923 ◽  
Author(s):  
J Landry ◽  
D Bernier ◽  
C Ouellet ◽  
R Goyette ◽  
N Marceau
Keyword(s):  
Extracellular Matrix ◽  
Rat Liver ◽  
Single Cells ◽  
Three Dimensional ◽  
Cell Types ◽  
Tyrosine Aminotransferase ◽  
Liver Cells ◽  
Specific Pattern ◽  
Extracellular Matrix Components ◽  
Matrix Components

Liver cells isolated from newborn rats and seeded on a non-adherent plastic substratum were found to spontaneously re-aggregate and to form, within a few days, spheroidal aggregates that eventually reached a plateaued diameter of 150-175 micron. Analyses on frozen sections from these spheroids by immunofluorescence microscopy using antibodies to various cytoskeletal elements and extracellular matrix components revealed a sorting out and a histotypic reorganization of three major cell types. A first type consisted of cells that segregated out on the aggregate surface forming a monolayer cell lining; a second type was identified as hepatocytes that regrouped in small islands often defining a central lumen; and a third group of cells reorganized into bile duct-like structures. This intercellular organization in the aggregates was paralleled by the accumulation of extracellular matrix components (laminin, fibronectin, and collagen) and their deposition following a specific pattern around each cell population structure. Determinations of albumin secretion and tyrosine aminotransferase induction by dexamethasone and glucagon at various times after the initiation of the cultures revealed a maintenance of the hepatocyte-differentiated functions for at least up to 2 mo at the levels measured at 3-5 d. It is concluded that cells dispersed as single cells from newborn rat liver conserve in part the necessary information to reconstruct a proper three-dimensional cyto-architecture and that the microenvironment so generated most likely represents a basic requirement for the optimal functioning of these differentiated cells.

scholarly journals Spatial organization of different sigma factor activities and c-di-GMP signalling within the three-dimensional landscape of a bacterial biofilm

Open Biology ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 180066 ◽  
Author(s):  
Gisela Klauck ◽  
Diego O. Serra ◽  
Alexandra Possling ◽  
Regine Hengge
Keyword(s):  
Gene Expression ◽  
Extracellular Matrix ◽  
Stationary Phase ◽  
Sigma Factor ◽  
Spatial Organization ◽  
Expression Patterns ◽  
Three Dimensional ◽  
Biomechanical Properties ◽  
Ribosomal Gene ◽  
Bacterial Biofilm

Bacterial biofilms are large aggregates of cells embedded in an extracellular matrix of self-produced polymers. In macrocolony biofilms of Escherichia coli , this matrix is generated in the upper biofilm layer only and shows a surprisingly complex supracellular architecture. Stratified matrix production follows the vertical nutrient gradient and requires the stationary phase σ S (RpoS) subunit of RNA polymerase and the second messenger c-di-GMP. By visualizing global gene expression patterns with a newly designed fingerprint set of Gfp reporter fusions, our study reveals the spatial order of differential sigma factor activities, stringent control of ribosomal gene expression and c-di-GMP signalling in vertically cryosectioned macrocolony biofilms. Long-range physiological stratification shows a duplication of the growth-to-stationary phase pattern that integrates nutrient and oxygen gradients. In addition, distinct short-range heterogeneity occurs within specific biofilm strata and correlates with visually different zones of the refined matrix architecture. These results introduce a new conceptual framework for the control of biofilm formation and demonstrate that the intriguing extracellular matrix architecture, which determines the emergent physiological and biomechanical properties of biofilms, results from the spatial interplay of global gene regulation and microenvironmental conditions. Overall, mature bacterial macrocolony biofilms thus resemble the highly organized tissues of multicellular organisms.

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