| 1. |
- Améen, Caroline, 1975, et al.
(author)
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Human embryonic stem cells: current technologies and emerging industrial applications.
- 2008
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In: Critical reviews in oncology/hematology. - : Elsevier BV. - 1040-8428. ; 65:1, s. 54-80
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Research review (peer-reviewed)abstract
- The efficiency and accuracy of the drug development process is severely restricted by the lack of functional human cell systems. However, the successful derivation of pluripotent human embryonic stem (hES) cell lines in the late 1990s is expected to revolutionize biomedical research in many areas. Due to their growth capacity and unique developmental potential to differentiate into almost any cell type of the human body, hES cells have opened novel avenues both in basic and applied research as well as for therapeutic applications. In this review we describe, from an industrial perspective, the basic science that underlies the hES cell technology and discuss the current and future prospects for hES cells in novel and improved stem cell based applications for drug discovery, toxicity testing as well as regenerative medicine.
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| 2. |
- Bigdeli, Narmin, 1974, et al.
(author)
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Adaptation of human embryonic stem cells to feeder-free and matrix-free culture conditions directly on plastic surfaces.
- 2008
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In: Journal of biotechnology. - : Elsevier BV. - 0168-1656. ; 133:1, s. 146-53
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Journal article (peer-reviewed)abstract
- Previous studies have shown that cultivation of undifferentiated human embryonic stem (hES) cells requires human fibroblasts (hF) or mouse embryonic fibroblast (mEF) feeders or a coating matrix such as laminin, fibronectin or Matrigeltrade mark in combination with mEF or hF conditioned medium. We here demonstrate a successful feeder-free and matrix-free culture system in which undifferentiated hES cells can be cultured directly on plastic surfaces without any supportive coating, in a hF conditioned medium. The hES cells cultured directly on plastic surfaces grow as colonies with morphology very similar to cells cultured on Matrigel(TM). Two hES cell lines SA167 and AS034.1 were adapted to matrix-free growth (MFG) and have so far been cultured up to 43 passages and cryopreserved successfully. The lines maintained a normal karyotype and expressed the expected marker profile of undifferentiated hES cells for Oct-4, SSEA-3, SSEA-4, TRA-1-60, TRA-1-81 and SSEA-1. The hES cells formed teratomas in SCID mice and differentiated in vitro into derivates of all three germ layers. Thus, the MFG-adapted hES cells appear to retain pluripotency and to remain undifferentiated. The present culture system has a clear potential to be scaleable up to a manufacturing level and become the preferred culture system for various applications such as cell therapy and toxicity testing.
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| 3. |
- Bigdeli, Narmin, 1974, et al.
(author)
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Coculture of human embryonic stem cells and human articular chondrocytes results in significantly altered phenotype and improved chondrogenic differentiation.
- 2009
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In: Stem cells (Dayton, Ohio). - : Oxford University Press (OUP). - 1549-4918 .- 1066-5099. ; 27:8, s. 1812-21
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Journal article (peer-reviewed)abstract
- Human embryonic stem (hES) cells have been suggested as a cell source for the repair of cartilage lesions. Here we studied how coculture with human articular chondrocytes affects the expansion potential, morphology, expression of surface markers, and differentiation abilities of hES cells, with special regard to chondrogenic differentiation. Undifferentiated hES cells were cocultured with irradiated neonatal or adult articular chondrocytes in high-density pellet mass cultures for 14 days. Cocultured hES cells were then expanded on plastic and their differentiation potential toward the adipogenic, osteogenic, and chondrogenic lineages was compared with that of undifferentiated hES cells. The expression of different surface markers was investigated using flow cytometry and teratoma formation was studied using injection of the cells under the kidney capsule. Our results demonstrate that although hES cells have to be grown on Matrigel, the cocultured hES cells could be massively expanded on plastic with a morphology and expression of surface markers similar to mesenchymal stem cells. Coculture further resulted in a more homogenous pellet and significantly increased cartilage matrix production, both in high-density pellet mass cultures and hyaluronan-based scaffolds. Moreover, cocultured cells formed colonies in agarose suspension culture, also demonstrating differentiation toward chondroprogenitor cells, whereas no colonies were detected in the hES cell cultures. Coculture further resulted in a significantly decreased osteogenic potential. No teratoma formation was detected. Our results confirm the potential of the culture microenvironment to influence hES cell morphology, expansion potential, and differentiation abilities over several population doublings.
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| 4. |
- Strehl, Raimund, et al.
(author)
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Long-term maintenance of human articular cartilage in culture for biomaterial testing.
- 2005
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In: Biomaterials. - : Elsevier BV. - 0142-9612. ; 26:22, s. 4540-9
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Journal article (peer-reviewed)abstract
- Cartilage is a tissue that derives its unique mechanical and biological properties from the combination of relatively few cells and a large amount of a complex extracellular matrix. Furthermore, cartilage tissue is comparatively slow to respond to changes or harmful influences. To date, the optimal generation and long-term maintenance of cultured human articular cartilage for in vitro testing of biomaterials, poses an experimental difficulty. Experiments using cultured isolated chondrocytes in combination with scaffolds often fail to yield results comparable to the in-vivo situation. Consequently, our aim was to develop a culture method that allows in vitro maintenance of human hyaline cartilage explants in an optimal quality over an extended period of time. Such a culture could, for example, be used to determine the long-term effect of a new scaffold on intact cartilage, as an in vitro model for repair processes and to investigate biomaterial integration. In this study we compared conventional static cultures with and without serum supplementation to a serum-free perfusion culture for the ability to maintain human articular cartilage explants in a morphologically intact and differentiated state over an extended period of time of up to 56 days. Results were evaluated and compared by morphological, histochemical and immunohistochemical methods. The experiments showed that short-term maintenance of cartilage in a differentiated state for up to 14 days is possible under all culture conditions tested. However, best long-term culture results for up to 56 days were obtained with perfusion culture under serum-free conditions. Such a perfusion culture system can be used to perform biocompatabilty tests in vitro by long-term coculture of biomaterial and intact human articular cartilage.
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