Enzyme-free release of adhered cells from standard culture dishes using intermittent ultrasonic traveling waves.

Cell detachment is essential in culturing adherent cells. Trypsinization is the most popular detachment technique, even though it reduces viability due to the damage to the membrane and extracellular matrix. Avoiding such damage would improve cell culture efficiency. Here we propose an enzyme-free cell detachment method that employs the acoustic pressure, sloshing in serum-free medium from intermittent traveling wave. This method detaches 96.2% of the cells, and increases its transfer yield to 130% of conventional methods for 48 h, compared to the number of cells detached by trypsinization. We show the elimination of trypsinization reduces cell damage, improving the survival of the detached cells. Acoustic pressure applied to the cells and media sloshing from the intermittent traveling wave were identified as the most important factors leading to cell detachment. This proposed method will improve biopharmaceutical production by expediting the amplification of tissue-cultured cells through a more efficient transfer process

Il libro di Daniele e l'apocalittica ebraica antica

1. Un genere letterario e una visione del mondo. 2. La letteratura apocalittica ebraica. 3. Le radici dell'apocalittica ebraica. 4. Apocalittica, enochismo, qumranesimo. 5. Il libro di Daniele. 6. Le principali apocalissi non canoniche

Application of Microfluidics in Stem Cell Culture

In this chapter, we review the recent developments, including our studies on the microfabricated devices applicable to stem cell culture. We will focus on the application of pluripotent stem cells including embryonic stem cells and induced pluripotent stem cells. In the first section, we provide a background on microfluidic devices, including their fabrication technology, characteristics, and the advantages of their application in stem cell culture. The second section outlines the use of micropatterning technology in stem cell culture. The use of microwell array technology in stem cell culture is explored in the third section. In the fourth section, we discuss the use of the microfluidic perfusion culture system for stem cell culture, and the last section is a summary of the current state of the art and perspectives of microfluidic technologies in stem cell culture

Antibacterial Properties Of Laser Surface-Textured TiO2/ZnO Ceramic Coatings

Bacterial attachment on surfaces cause fouling, which reduces the hygiene status and effectiveness of equipment. Preventing bacterial attachment on surfaces through surface modification is a potential solution to fouling and has thus become a key research area. In this study, the effect of different ZnO contents (wt%) and picosecond laser surface texturing on the antibacterial properties of TiO2/ZnO ceramic coatings were investigated. The attachment and viability of Escherichia coli (E. coli) bacteria on laser surface-textured and non-textured TiO2/ZnO ceramic coatings were explored. Bacterial growth in an immersion suspension was evaluated using the optical density method. The number of colony-forming units on laser surface textured TiO2/ZnO coatings was found to be lower than that on non-textured coatings, which indicates that laser surface-textured coatings demonstrate strong antibacterial properties. Furthermore, the number of viable E. coli bacteria on laser surfacetextured TiO2/ZnO coatings was observed to be lower than that on non-textured coatings. This finding also demonstrates that laser surface texturing enhances the antibacterial properties of TiO2/ZnO coatings. Overall, laser surface texturing increased the surface areas of the coatings and improved the effectiveness of ZnO as an antibacterial agent. These results prove that laser surface texturing is a successful method for fabricating antibacterial surface

Reduction of N-Glycolylneuraminic Acid in Human Induced Pluripotent Stem Cells Generated or Cultured under Feeder- and Serum-Free Defined Conditions

BACKGROUND: The successful establishment of human induced pluripotent stem cells (hiPSCs) has increased the possible applications of stem cell research in biology and medicine. In particular, hiPSCs are a promising source of cells for regenerative medicine and pharmacology. However, one of the major obstacles to such uses for hiPSCs is the risk of contamination from undefined pathogens in conventional culture conditions that use serum replacement and mouse embryonic fibroblasts as feeder cells. METHODOLOGY/PRINCIPAL FINDINGS: Here we report a simple method for generating or culturing hiPSCs under feeder- and serum-free defined culture conditions that we developed previously for human embryonic stem cells. The defined culture condition comprises a basal medium with a minimal number of defined components including five highly purified proteins and fibronectin as a substrate. First, hiPSCs, which were generated using Yamanaka's four factors and conventional undefined culture conditions, adapted to the defined culture conditions. These adapted cells retained the property of self renewal as evaluated morphologically, the expression of self-renewal marker proteins, standard growth rates, and pluripotency as evaluated by differentiation into derivatives of all three primary germ layers in vitro and in vivo (teratoma formation in immunodeficient mice). Moreover, levels of nonhuman N-glycolylneuraminic acid (Neu5Gc), which is a xenoantigenic indicator of pathogen contamination in human iPS cell cultures, were markedly decreased in hiPSCs cultured under the defined conditions. Second, we successfully generated hiPSCs using adult dermal fibroblast under the defined culture conditions from the reprogramming step. For a long therm culture, the generated cells also had the property of self renewal and pluripotency, they carried a normal karyotype, and they were Neu5Gc negative. CONCLUSION/SIGNIFICANCE: This study suggested that generation or adaption culturing under defined culture conditions can eliminate the risk posed by undefined pathogens. This success in generating hiPSCs using adult fibroblast would be beneficial for clinical application

BMP4 induction of trophoblast from mouse embryonic stem cells in defined culture conditions on laminin

Because mouse embryonic stem cells (mESCs) do not contribute to the formation of extraembryonic placenta when they are injected into blastocysts, it is believed that mESCs do not differentiate into trophoblast whereas human embryonic stem cells (hESCs) can express trophoblast markers when exposed to bone morphogenetic protein 4 (BMP4) in vitro. To test whether mESCs have the potential to differentiate into trophoblast, we assessed the effect of BMP4 on mESCs in a defined monolayer culture condition. The expression of trophoblast-specific transcription factors such as Cdx2, Dlx3, Esx1, Gata3, Hand1, Mash2, and Plx1 was specifically upregulated in the BMP4-treated differentiated cells, and these cells expressed trophoblast markers. These results suggest that BMP4 treatment in defined culture conditions enabled mESCs to differentiate into trophoblast. This differentiation was inhibited by serum or leukemia inhibitory factor, which are generally used for mESC culture. In addition, we studied the mechanism underlying BMP4-directed mESC differentiation into trophoblast. Our results showed that BMP4 activates the Smad pathway in mESCs inducing Cdx2 expression, which plays a crucial role in trophoblast differentiation, through the binding of Smad protein to the Cdx2 genomic enhancer sequence. Our findings imply that there is a common molecular mechanism underlying hESC and mESC differentiation into trophoblast

Maruyama_Migration_human_mesoderm_endoderm_IVAN2024

The migration pattern of cells during the mesoderm and endoderm differentiation from human pluripotent stem cellsRunning head: Migration of human mesoderm and endodermKenshiro Maruyama1, Shota Miyazaki2, Ryo Kobayashi2, Haru Hikita3, Tadashi Tsubone3, Kiyoshi Ohnuma1, 2,*1Department of Science of Technology Innovation, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan2Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan3Department of Electrical, Electronics and Information Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan* Correspondence should be addressed to Kiyoshi OhnumaE-mail: [email protected]; Tel & Fax: +81-258-47-9454 </p