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Tissue Culture Plates (tissue + culture_plate)
Selected AbstractsMass Fabrication of Small Cell Spheroids by Using Micro-patterned Tissue Culture Plate,ADVANCED ENGINEERING MATERIALS, Issue 10 2009Akinari Iwasaki A newly designed micro-patterned chamber was utilized to fabricate cell spheroids with a constant size (<200,,m) and cell number. By applying cytochalasin D as a chemical to control cell adhesion and aggregation, thousands of aggregated cells were formed in each patterned chamber. Importantly, the formed cell spheroids were collected by a simple pipetting process without using proteinase. [source] Hypoxia suppresses runx2 independent of modeled microgravityJOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2004Christopher Ontiveros Bone loss is a consequence of skeletal unloading as seen in bed rest and space flight. Unloading decreases oxygenation and osteoblast differentiation/function in bone. Previously we demonstrated that simulation of unloading in vitro, by culturing differentiating mouse osteoblasts in a horizontal rotating wall vessel (RWV), results in suppressed expression of runx2, a master transcriptional regulator of osteoblast differentiation. However, the RWV is able to reproduce in a controlled fashion at least two aspects of disuse that are directly linked, model microgravity and hypoxia. Hypoxia in the RWV is indicated by reduced medium oxygen tension and increased expression of GAPDH and VEGF. To uncouple the role of model microgravity from hypoxia in suppressed runx2 expression, we cultured osteoblasts under modeled microgravity (oxygenated, horizontal RWV rotation), hypoxia (vertical RWV rotation), or both conditions (horizontal RWV rotation). The expression, DNA binding activity and promoter activity of runx2, was suppressed under hypoxic but not normoxic modeled microgravity RWV conditions. Consistent with a role for hypoxia in suppression of runx2, direct exposure to hypoxia alone is sufficient to suppress runx2 expression in osteoblasts grown in standard tissue culture plates. Taken together, our findings indicate that hypoxia associated with skeletal unloading could be major suppressor of runx2 expression leading to suppressed osteoblast differentiation and bone formation. © 2004 Wiley-Liss, Inc. [source] A NEW LARVAL FISH BIOASSAY FOR TESTING THE PATHOGENICITY OF PFIESTERIA SPP. (DINOPHYCEAE),JOURNAL OF PHYCOLOGY, Issue 3 2003Vincent J. Lovko Water quality, microbial contamination, prior fish health, and variable results have been major impediments to identifying the cause and mechanism of fish mortality in standard aquarium-format Pfiesteria bioassays. Therefore, we developed a sensitive 96-h larval fish bioassay for assessing Pfiesteria spp. pathogenicity using six-well tissue culture plates and 7-day-old larval cyprinodontid fish. We used the assay to test pathogenicity of several clonal lines of Pfiesteria piscicida Steidinger and Burkholder and P. shumwayae Glasgow and Burkholder that had been cultured with algal prey for 2 to 36 months. The P. shumwayae cultures exhibited 80%,100% cumulative mortality in less than 96 h at initial zoospore densities of approximately 1000 cells·mL,1. No fish mortalities occurred with P. piscicida at identical densities or in controls. In a dose-response assay, we demonstrated a strong positive correlation between dinospore density and fish mortality in a highly pathogenic culture of P. shumwayae, generating a 96-h LD50 of 108 zoospores·mL,1. Additionally, we applied the assay to evaluate a 38-L P. shumwayae bioassay that was actively killing fish and compared results with those from exposures of juvenile tilapia (Oreochromis niloticus) in a 500-mL assay system. Water from the fish-killing 38-L assay was filtered and centrifuged to produce fractions dominated by dinoflagellates, bacteria, or presumed ichthyotoxin (cell-free fraction). After 96 h, the larval fish assay exhibited 50%,100% cumulative mortality only in fractions containing dinoflagellates, with no mortalities occurring in the other fractions. The 500-mL bioassay with tilapia produced inconsistent results and demonstrated no clear correlation between mortality and treatment. The new larval fish bioassay was demonstrated as a highly effective method to verify and evaluate dinoflagellate pathogenicity. [source] Polypyrrole Thin Films Formed by Admicellar Polymerization Support the Osteogenic Differentiation of Mesenchymal Stem CellsMACROMOLECULAR BIOSCIENCE, Issue 8 2004Harold Castano Abstract Summary: The objective of this study was to evaluate the attachment, proliferation, and differentiation of rat mesenchymal stem cells (MSC) toward the osteoblastic phenotype seeded on polypyrrole (PPy) thin films made by admicellar polymerization. Three different concentrations of pyrrole (Py) monomer (20, 35, and 50,×,10,3M) were used with the PPy films deposited on tissue culture polystyrene dishes (TCP). Regular TCP dishes and PPy polymerized on TCP by chemical polymerization without surfactant using 5,×,10,3M Py, were used as controls. Rat MSC were seeded on these surfaces and cultured for up to 20 d in osteogenic media. Surface topography was characterized by atomic force microscopy, X-ray photoelectron spectroscopy, and static contact angle. Cell attachment, proliferation, alkaline phosphatase (ALP) activity, and calcium content were measured to evaluate the ability of MSC to adhere and differentiate on PPy-coated TCP. Increased monomer concentrations resulted in PPy films of increased thickness and surface roughness. PPy films generated by different monomer concentrations induced drastically different cellular events. A wide spectrum of cell attachment characteristics (from excellent cell attachment to the complete inability to adhere) were obtained by varying the monomer concentration from 20 m to 50,×,10,3M. In particular the 20,×,10,3M PPy thin films demonstrated superior induction of MSC osteogenicity, which was comparable to standard TCP dishes, unlike PPy films of similar thickness prepared by chemical polymerization without surfactant. Adhesion of mesenchymal stem cells on tissue culture plates (TCP) coated with polypyrrole thin films made by admicellar polymerization. [source] Collagen barrier membranes decrease osteoclastogenesis in murine bone marrow culturesCLINICAL ORAL IMPLANTS RESEARCH, Issue 6 2010Hermann Agis Abstract Objective: Collagen barrier membranes (CBM) are used for guided bone regeneration to support the process of graft consolidation. It remains, unknown however, whether CBM can affect the consolidation of bone grafts by controlling the differentiation of progenitor cells into bone-resorbing osteoclasts and bone-forming osteoblasts. Material and Methods: To gain an insight into the underlying mechanisms, we performed in vitro bone marrow cultures on CBM (Bio-Gide®) under conditions that favor osteoclastogenesis and osteoblastogenesis, respectively. Measures of osteoclastogenesis were based on the number of tartrate-resistant acid-phosphatase-positive (TRAP+) multinucleated cells. Resorption assays revealed the activity of mature osteoclasts. Osteoblastogenesis was determined by alkaline-phosphatase activity. Viability was investigated utilizing the MTT assay. Results: Cultivation of murine bone marrow on CBM reduced the number of TRAP+ multinucleated cells compared with cultures on tissue culture plates. Inhibition of osteoclastogenesis was observed on the porous and the dense CBM surfaces. The majority of TRAP+ cells were mononucleated and the decreased osteoclastogenesis was not due to changes in cell viability. Furthermore, CBM are inert regarding the resorptive activity of mature osteoclasts. Moreover, osteoblastogenesis was not reduced when bone marrow cells were grown on the surface of CBM. Conclusions: These in vitro findings demonstrate that CBM can reduce the formation but not the activity of multinucleated osteoclasts. Our data further reveal that the formation of osteogenic cells from their progenitors is not reduced by the CBM. Overall, our results suggest that the beneficial effects of CBM during graft consolidation may involve their direct impact on osteoclastogenesis. To cite this article: Agis H, Magdalenko M, Stögerer K, Watzek G, Gruber R. Collagen barrier membranes decrease osteoclastogenesis in murine bone marrow cultures. Clin. Oral Impl. Res. 21, 2010; 656,661. doi: 10.1111/j.1600-0501.2009.01888.x [source] | |||||||||||||