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Dynamic Culture (dynamic + culture)
Selected AbstractsDynamic culture of droplet-confined cell arraysBIOTECHNOLOGY PROGRESS, Issue 1 2010Elisa Cimetta Abstract Responding to the need of creating an accurate and controlled microenvironment surrounding the cell while meeting the requirements for biological processes or pharmacological screening tests, we aimed at designing and developing a microscaled culture system suitable for analyzing the synergic effects of extracellular matrix proteins and soluble environments on cell phenotype in a high-throughput fashion. We produced cell arrays deposing micrometer-scale protein islands on hydrogels using a robotic DNA microarrayer, constrained the culture media in a droplet-like volume and developed a suitable perfusion system. The droplet-confined cell arrays were used either with conventional culture methods (batch operating system) or with automated stable and constant perfusion (steady-state operating system). Mathematical modeling assisted the experimental design and assessed efficient mass transport and proper fluidodynamic regimes. Cells cultured on arrayed islands (500 ,m diameter) maintained the correct phenotype both after static and perfused conditions, confirmed by immunostaining and gene expression analyses through total RNA extraction. The mathematical model, validated using a particle tracking experiment, predicted the constant value of velocities over the cell arrays (less than 10% variation) ensuring the same mass transport regime. BrdU analysis on an average of 96 cell spots for each experimental condition showed uniform expression inside each cell island and low variability in the data (average of 13%). Perfused arrays showed longer doubling times when compared with static cultures. In addition, perfused cultures showed a reduced variability in the collected data, allowing to detect statistically significant differences in cell behavior depending on the spotted ECM protein. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Rotating three-dimensional dynamic culture of adult human bone marrow-derived cells for tissue engineering of hyaline cartilageJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2009Shinsuke Sakai Abstract The method of constructing cartilage tissue from bone marrow-derived cells in vitro is considered a valuable technique for hyaline cartilage regenerative medicine. Using a rotating wall vessel (RWV) bioreactor developed in a NASA space experiment, we attempted to efficiently construct hyaline cartilage tissue from human bone marrow-derived cells without using a scaffold. Bone marrow aspirates were obtained from the iliac crest of nine patients during orthopedic operation. After their proliferation in monolayer culture, the adherent cells were cultured in the RWV bioreactor with chondrogenic medium for 2 weeks. Cells from the same source were cultured in pellet culture as controls. Histological and immunohistological evaluations (collagen type I and II) and quantification of glycosaminoglycan were performed on formed tissues and compared. The engineered constructs obtained using the RWV bioreactor showed strong features of hyaline cartilage in terms of their morphology as determined by histological and immunohistological evaluations. The glycosaminoglycan contents per µg DNA of the tissues were 10.01,±,3.49 µg/µg DNA in the case of the RWV bioreactor and 6.27,±,3.41 µg/µg DNA in the case of the pellet culture, and their difference was significant. The RWV bioreactor could provide an excellent environment for three-dimensional cartilage tissue architecture that can promote the chondrogenic differentiation of adult human bone marrow-derived cells. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 517,521, 2009 [source] Establishment of Three-Dimensional Tissue-engineered Bone Constructs Under Microgravity-simulated ConditionsARTIFICIAL ORGANS, Issue 2 2010Fang Jin Abstract Bone constructs have been grown in vitro with use of isolated cells, biodegradable polymer scaffolds, and bioreactors. In our work, the relationships between the composition and mechanical properties of engineered bone constructs were studied by culturing bone marrow mesenchymal stem cells (BMSCs) on ceramic bovine bone scaffolds in different environments: static flasks and dynamic culture system in rotating vessels,which was a National Aeronautics and Space Administration-recommended, ground-based, microgravity-simulating system. After 15 days of cultivation, osteogenicity was determined according to DNA and alkaline phosphatase (ALP) analysis. DNA content and ALP were higher for cells grown on dynamic culture. Subsequently, the two kinds of engineered bone constructs were selected for transplantation into Sprague-Dawley rat cranial bone defects. After 24 weeks of in vivo implantation, the engineered bone constructs under dynamic culture were found to repair the defects better, with the engineered constructs showing histologically better bone connection. Thus, this dynamic system provides a useful in vitro model to construct the functional role and effects of osteogenesis in the proliferation, differentiation, and maturation of BMSCs. These findings suggest that the hydrodynamic microgravity conditions in tissue-culture bioreactors can modulate the composition, morphology, and function of the engineered bone. [source] In vitro liver model using microfabricated scaffolds in a modular bioreactorBIOTECHNOLOGY JOURNAL, Issue 2 2010Bruna Vinci Abstract Hepatocyte function on 3-D microfabricated polymer scaffolds realised with the pressure-activated microsyringe was tested under static and dynamic conditions. The dynamic cell culture was obtained using the multicompartment modular bioreactor system. Hepatocyte cell density, glucose consumption, and albumin secretion rate were measured daily over a week. Cells seeded on scaffolds showed an increase in cell density compared with monolayer controls. Moreover, in dynamic culture, cell metabolic function increased three times in comparison with static monolayer cultures. These results suggest that cell density and cell-cell interactions are mediated by the architecture of the substrate, while the endogenous biochemical functions are regulated by a sustainable supply of nutrients and interstitial-like flow. Thus, a combination of 3-D scaffolds and dynamic flow conditions are both important for the development of a hepatic tissue model for applications in drug testing and regenerative medicine. [source] | ||||||||||