WorldWideScience

Sample records for cell culture harvest

  1. Automated harvesting and 2-step purification of unclarified mammalian cell-culture broths containing antibodies.

    Science.gov (United States)

    Holenstein, Fabian; Eriksson, Christer; Erlandsson, Ioana; Norrman, Nils; Simon, Jill; Danielsson, Åke; Milicov, Adriana; Schindler, Patrick; Schlaeppi, Jean-Marc

    2015-10-30

    Therapeutic monoclonal antibodies represent one of the fastest growing segments in the pharmaceutical market. The growth of the segment has necessitated development of new efficient and cost saving platforms for the preparation and analysis of early candidates for faster and better antibody selection and characterization. We report on a new integrated platform for automated harvesting of whole unclarified cell-culture broths, followed by in-line tandem affinity-capture, pH neutralization and size-exclusion chromatography of recombinant antibodies expressed transiently in mammalian human embryonic kidney 293T-cells at the 1-L scale. The system consists of two bench-top chromatography instruments connected to a central unit with eight disposable filtration devices used for loading and filtering the cell cultures. The staggered parallel multi-step configuration of the system allows unattended processing of eight samples in less than 24h. The system was validated with a random panel of 45 whole-cell culture broths containing recombinant antibodies in the early profiling phase. The results showed that the overall performances of the preparative automated system were higher compared to the conventional downstream process including manual harvesting and purification. The mean recovery of purified material from the culture-broth was 66.7%, representing a 20% increase compared to that of the manual process. Moreover, the automated process reduced by 3-fold the amount of residual aggregates in the purified antibody fractions, indicating that the automated system allows the cost-efficient and timely preparation of antibodies in the 20-200mg range, and covers the requirements for early in vitro and in vivo profiling and formulation of these drug candidates. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  2. Improvement on light penetrability and microalgae biomass production by periodically pre-harvesting Chlorella vulgaris cells with culture medium recycling.

    Science.gov (United States)

    Huang, Yun; Sun, Yahui; Liao, Qiang; Fu, Qian; Xia, Ao; Zhu, Xun

    2016-09-01

    To improve light penetrability and biomass production in batch cultivation, a cultivation mode that periodically pre-harvesting partial microalgae cells from suspension with culture medium recycling was proposed. By daily pre-harvesting 30% microalgae cells from the suspension, the average light intensity in the photobioreactor (PBR) was enhanced by 27.05-122.06%, resulting in a 46.48% increase in total biomass production than that cultivated in batch cultivation without pre-harvesting under an incident light intensity of 160μmolm(-2)s(-1). Compared with the semi-continuous cultivation with 30% microalgae suspension daily replaced with equivalent volume of fresh medium, nutrients and water input was reduced by 60% in the proposed cultivation mode but with slightly decrease (12.82%) in biomass production. No additional nutrient was replenished when culture medium recycling. Furthermore, higher pre-harvesting ratios (40%, 60%) and lower pre-harvesting frequencies (every 2, 2.5days) were not advantageous for the pre-harvesting cultivation mode. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Harvesting Culture and Literacy

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    THROUGH efforts to wipe out illiteracy and spread cultural and scientific knowledge in Panjin, Liaoning Province, rural illiterate and semi-literate women were able to read and write by the end of 1991. Many of

  4. Capillary size exclusion chromatography with picogram sensitivity for analysis of monoclonal antibodies purified from harvested cell culture fluid.

    Science.gov (United States)

    Rea, Jennifer C; Moreno, G Tony; Vampola, Lisa; Lou, Yun; van Haan, Bjorn; Tremintin, Guillaume; Simmons, Laura; Nava, Adrian; Wang, Yajun Jennifer; Farnan, Dell

    2012-01-06

    Size exclusion chromatography (SEC) is widely used in the characterization and quality control of therapeutic proteins to detect aggregates. Aggregation is a carefully monitored quality attribute from the earliest stages of clinical development owing to the possibility of eliciting an immunogenic response in the patient. During early stage molecule assessment for cell culture production, small-scale screening experiments are performed to permit rapid turn-around of results so as to not delay timelines. We report the development of a capillary SEC methodology for preliminary molecule assessment to support the evaluation of therapeutic candidates at an early stage of development. By making several key modifications to a commercially available liquid chromatography system, we demonstrate a platform process to perform capillary SEC with excellent precision, picogram sensitivity and good ruggedness. The limit of quantitation was determined to be approximately 15 pg; picogram sensitivity for SEC analysis of monoclonal antibodies had not been achieved prior to this work. In addition, we have developed a method to capture low levels of antibody (1 μg/mL) from harvested cell culture fluid (HCCF) for capillary SEC analysis. Up to 40% recovery efficiency was achieved using this micro-recovery method on 3 mL HCCF samples. Using early stage cell culture transient transfection samples, which typically have much lower titers than stable cell line samples, we demonstrate a consistent method for analyzing aggregates in low protein concentration HCCF samples for molecule assessment and early stage candidate screening. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Harvest managements and cultural practices in sugarcane

    Directory of Open Access Journals (Sweden)

    Sérgio Gustavo Quassi de Castro

    2014-02-01

    Full Text Available The presence of trash from the mechanical harvest of green cane on sugarcane plantations promotes changes in the agricultural management, for example, in the mechanical cultural practices of ratoon cane in-between the rows and nitrogen (N fertilization. The goal of this study was to evaluate the performance of sugarcane in different harvest systems, associated to the mechanical cultural practices in interrows and N rates. The study was carried out on a sugarcane plantation in Sales Oliveira, São Paulo, Brazil, with the sugarcane variety SP81-3250, on soil classified as Acrudox, in a randomized block design with split-split plots and four replications. The main treatments consisted of harvest systems (harvesting green cane or burnt cane, the secondary treatment consisted of the mechanical cultural practices in the interrows and the tertiary treatments were N rates (0, 30, 60, 90, 120 and 160 kg ha-1, using ammonium nitrate (33 % N as N source. The harvest systems did not differ in sugarcane yield (tons of cane per hectare - TCH, but in burnt cane, the pol percent and total sugar recovery (TSR were higher. This could be explained by the higher quantity of plant impurities in the harvested raw material in the system without burning, which reduces the processing quality. Mechanical cultural practices in the interrows after harvest had no effect on cane yield and sugar quality, indicating that this operation can be omitted in areas with mechanical harvesting. The application of N fertilizer at rates of 88 and 144 kg ha-1 N, respectively, increased stalk height and TCH quadratically to the highest values for these variables. For the sugar yield per hectare (in pol %, N fertilization induced a linear increase.

  6. Treatment and electricity harvesting from sulfate/sulfide-containing wastewaters using microbial fuel cell with enriched sulfate-reducing mixed culture

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Duu-Jong, E-mail: cedean@mail.ntust.edu.tw [Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan (China); Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan (China); Lee, Chin-Yu [Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan (China); Chang, Jo-Shu [Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan (China); Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan, Taiwan (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer We started up microbial fuel cell (MFC) using enriched sulfate-reducing mixed culture. Black-Right-Pointing-Pointer Sulfate-reducing bacteria and anode-respiring bacteria were enriched in anodic biofilms. Black-Right-Pointing-Pointer The MFC effectively remove sulfate to elementary sulfur in the presence of lactate. Black-Right-Pointing-Pointer The present device can treat sulfate laden wastewaters with electricity harvesting. - Abstract: Anaerobic treatment of sulfate-laden wastewaters can produce excess sulfide, which is corrosive to pipelines and is toxic to incorporated microorganisms. This work started up microbial fuel cell (MFC) using enriched sulfate-reducing mixed culture as anodic biofilms and applied the so yielded MFC for treating sulfate or sulfide-laden wastewaters. The sulfate-reducing bacteria in anodic biofilm effectively reduced sulfate to sulfide, which was then used by neighboring anode respiring bacteria (ARB) as electron donor for electricity production. The presence of organic carbons enhanced MFC performance since the biofilm ARB were mixotrophs that need organic carbon to grow. The present device introduces a route for treating sulfate laden wastewaters with electricity harvesting.

  7. Microalgae harvesting via co-culture with filamentous fungus

    Science.gov (United States)

    Gultom, Sarman Oktovianus

    Microalgae harvesting is a labor- and energy-intensive process. For instance, classical harvesting technologies such as chemical addition and mechanical separation are economically prohibiting for biofuel production. Newer approaches to harvest microalgae have been developed in order to decrease costs. Among these new methods, fungal co-pelletization seems to be a promising technology. By co-culturing filamentous fungi with microalgae, it is possible to form pellets, which can easily be separated. In this study, different parameters for the cultivation of filamentous fungus (Aspergillus niger) and microalgae (Chlorella vulgaris) to efficiently form cell pellets were evaluated under heterotrophic and phototrophic conditions, including organic carbon source (glucose, glycerol and sodium acetate) concentration, pH, initial concentration of fungal spores, initial concentration of microalgal cells, concentration of ionic strength (Calcium and Magnesium) and concentration of salinity (NaCl). In addition, zeta-potential measurements were carried out in order to get a better understanding of the mechanism of attraction. It was found that 2 g/L of glucose, a fungus to microalgae ratio of 1:300, and uncontrolled pH (around 7) are the best culturing conditions for co-pelletization. Under these conditions, it was possible to achieve a high harvesting performance (>90%). In addition, it was observed that most pellets formed in the co-culture were spherical with an average diameter of 3.5 mm and in concentrations of about 5 pellets per mL of culture media. Under phototrophic conditions, co-pelletization required the addition of glucose as organic carbon source to sustain the growth of fungi and to allow the harvesting of microalgae. Zeta-potential measurements indicated that (i) both microalgae and fungi have low zeta-potential values regardless of the pH on the bulk (i.e. <-10 mV) (ii) fungi can have a positive electric charge at low pH (ie. pH=3). These values suggest that it

  8. Selected Harvesting Machines For Short Rotation Intensive Culture Biomass Plantations

    Science.gov (United States)

    Sammy Woodfin; Doug Frederick; Bryce Stokes

    1987-01-01

    Three different harvesting systems were observed and analyzed for productivity and costs in a short rotation.intensive culture plantation of 2 to 5 year old sycamore. Individual machines were compared to create an optimum system.

  9. Myocardial Cell Pattern on Piezoelectric Nanofiber Mats for Energy Harvesting

    Science.gov (United States)

    Liu, X.; Wang, X.; Zhao, H.; Du, Y.

    2014-11-01

    The paper presents in vitro contractile myocardial cell pattern on piezoelectric nanofiber mats with applications in energy harvesting. The cell-based energy harvester consists of myocardial cell sheet and a PDMS substrate with a PVDF nanofiber mat on. Experimentally, cultured on specifically distributed nanofiber mats, neonatal rat ventricular cardiomyocytes are characterized with the related morphology and contraction. Previously, we have come up with the concept of energy harvesting from heart beating using piezoelectric material. A bio-hybrid energy harvester combined living cardiomyocytes, PDMS polymer substrate and piezoelectric PVDF film with the electrical output of peak current 87.5nA and peak voltage 92.3mV. However, the thickness of the cardiomyocyte cultured on a two-dimensional substrate is much less than that of the piezoelectric film. The Micro Contact Printing (μCP) method used in cell pattern on the PDMS thin film has tough requirement for the film surface. As such, in this paper we fabricated nanofiber-constructed PDMS thin film to realize cell pattern due to PVDF nanofibers with better piezoelectricity and microstructures of nanofiber mats guiding cell distribution. Living cardiomyocytes patterned on those distributed piezoelectric nanofibers with the result of the same distribution as the nanofiber pattern.

  10. Microalgal Mass Culture Room Harvest Records

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The microalgal mass culture room, housed at the NOAA Fisheries' Milford CT laboratory, provides research grade microalgae (phytoplankton) to in-house and...

  11. SandTraps are efficient, scalable, and mild systems for harvesting, washing and concentrating cells.

    Science.gov (United States)

    Frauenstein, Danny; Seidel, Katja; Adrian, Lorenz

    2017-01-01

    Microbial cells vary widely in size, specific density, shearing resistance, oxygen sensitivity and abundance so that differential harvesting and washing procedures are needed to efficiently recover cells from dilute suspensions. We here describe a mild, simple, variable and cost-efficient method to harvest cells on columns packed with silica beads. The method collects and concentrates 40-98% of the cells preserving enzymatic activity and cell viability. The method can be applied for strictly anaerobic microorganisms, is scalable to different culture volumes and can be multiplexed in standardized systems. We see major application potential in harvesting small cells leaking through 0.2μm filters, for harvesting strictly anaerobic cells and for differential harvesting of cells according to cell size using a gradient system.

  12. Microalgae Harvest through Fungal Pelletization—Co-Culture of Chlorella vulgaris and Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Sarman Oktovianus Gultom

    2014-07-01

    Full Text Available Microalgae harvesting is a labor- and energy-intensive process and new approaches to harvesting microalgae need to be developed in order to decrease the costs. In this study; co-cultivatation of filamentous fungus (Aspergillus niger and microalgae (Chlorella vulgaris to form cell pellets was evaluated under different conditions, including organic carbon source (glucose; glycerol; and sodium acetate concentration; initial concentration of fungal spores and microalgal cells and light. Results showed that 2 g/L of glucose with a 1:300 ratio of fungi to microalgae provided the best culturing conditions for the process to reach >90% of cell harvest efficiency. The results also showed that an organic carbon source was required to sustain the growth of fungi and form the cell pellets. The microalgae/fungi co-cultures at mixotrophic conditions obtained much higher total biomass than pure cultures of each individual strains; indicating the symbiotic relationship between two strains. This can benefit the microbial biofuel production in terms of cell harvest and biomass production.

  13. In situ digestion, in vitro harvest and culture of jugular vein endothelial cells in rabbits%兔颈静脉内皮细胞的原位消化、体外获取及培养

    Institute of Scientific and Technical Information of China (English)

    孙彦隽; 刘锦纷; 马宁

    2012-01-01

    目的 建立兔颈静脉内皮细胞原位消化、体外获取及培养的方法.方法 仅解剖游离单侧兔颈静脉,并保留在原位,对侧颈静脉不进行解剖游离.阻断该静脉段的两端并插管,向该静脉段内灌注Ⅰ型胶原酶进行原位消化.切取该颈静脉段,离体状态下获取兔颈静脉内皮细胞,使用EGM-2培养基培养并传代.倒置显微镜、透射电镜观察获取的兔颈静脉内皮细胞,免疫组化法检测Ⅷ因子.结果 获取的兔颈静脉内皮细胞原代培养7~10d左右可达到80%融合.光镜下细胞为短梭形或多角形,呈“鹅卵石”样排列.透射电镜可见内皮细胞特征性的Weibel-Palade小体.兔Ⅷ因子相关抗原免疫组化检测阳性.获取的兔颈静脉内皮细胞进行冻存、复苏和传代后均可以正常生长.结论 成功建立了兔颈静脉内皮细胞原位消化、体外获取及培养的方法.%Objective To establish the methodology for in situ digestion,in vitro harvest and culture of jugular vein endothelial cells in rabbits.Methods The jugular vein was dissected and kept in situ unilaterally,with the contralateral jugular vein intact.Both terminals of the dissected vein were occluded for cannulation and were subjected to type Ⅰ collagenase injection for in situ digestion.The operated jugular vein was resectcd for collecting endothelial cells in vitro,followed by culture and passage using EGM-2 culture medium.The jugular vein endothelial cells were observed under inverted light microscopy and transmission electron microscopy for morphological examination.In addition,factor Ⅷ was measured by immunohistochemistry assay.Results Of all jugular vein endothelial cells harvested,80% underwent fusion after a 7-to-10-day primary passage.These cells appeared in short spindle-like,polygonal or cobblestone-like arrangement under microscope.The characteristic Weible- Palade bodies of endothelial cells were found under transmission electron microscope

  14. Harvesting microalgae cultures with superabsorbent polymers: desulfurization of Chlamydomonas reinhardtii for hydrogen production.

    Science.gov (United States)

    Martín del Campo, Julia S; Patiño, Rodrigo

    2013-12-01

    It is presented in this work a new methodology to harvest fresh water microalgae cultures by extracting the culture medium with superabsorbent polymers (SAPs). The microalgae Chlamydomonas reinhardtii were grown in the Sueoka culture medium, harvested with polyacrylic SAPs and re-suspended in the culture medium tris-acetate-potassium without sulfur (TAP-S) to generate hydrogen (H2 ) under anoxic conditions. The H2 production as an alternative fuel is relevant since this gas has high-energy recovery without involving carbon. Before microalgae harvesting, a number of range diameters (1-7 mm) for SAPs spherical particles were tested, and the initial rate (V0 ) and the maximal capacity (Qmax ) were determined for the Sueoka medium absorption. The SAP particles with the diameter range 2.0-2.5 mm performed the best and these were employed for the rest of the experiments. The Sueoka medium has a high salt content and the effect of the ionic strength was also studied for different medium concentrations (0-400%). The SAPs were reused in consecutive absorption/desorption cycles, maintaining their absorption capacity. Although the Sueoka medium reduces the SAPs absorption capacity to 40% compared with deionized water, the use of SAPs was very significant for the desulfurization process of C. reihardtii. The presence of C. reinhardtii at different concentrations does not affect the absorption capacity of the Sueoka culture medium by the SAPs. In order to reduce the time of the process, an increase of the SAPs concentration was tested, being 20 g of SAP per liter of medium, a condition to harvest the microalgae culture in 4 h. There were no evident cell ruptures during the harvesting process and the cells remained alive. Finally, the harvested biomass was re-suspended in TAP-S medium and kept under anaerobic conditions and illumination to produce H2 that was monitored by a PEM fuel cell. The use of SAPs for microalgae harvesting is a feasible non-invasive procedure to obtain

  15. Harvesting

    Science.gov (United States)

    Since the introduction of the first successful mechanical harvester, mechanized cotton harvest has continued to decrease the cost and man hours required to produce a bale of cotton. Cotton harvesting in the US is completely mechanized and is accomplished by two primary machines, the spindle picker a...

  16. Harvesting of Dunaliella tertiolecta cells by magnetic filtration

    Science.gov (United States)

    Manousakis, Emmanouil; Manariotis, Ioannis D.

    2015-04-01

    The rising cost and reduced reserves of fossil fuels have enhanced the interest for finding alterative energy sources. Microalgae are considered to be the only sustainable option in biodiesel production for two key points. The energy yield from microalgae is much higher than that of oil producing crops, and the cultivation of algae it is not antagonistic with food supply chain. Because of the small size of microalgae and the dilute nature of algal cultures, the harvesting cost of microalgae is so far a limiting step for the scale up of microalgal biofuel production. It is estimated that the algal harvesting cost is at least 20-30% of the total biomass production cost. Traditional methods, which have been employed for the recovery of microalgal biomass, include centrifugation, gravity separation, filtration, flocculation, and flotation. Alternative approaches, other than conventional methods, capable of processing large cultures volume at a low cost, and reducing effluent toxicity are essential for microalgal biomass production. Magnetic separation is a promising technology and has been applied for algal removal in the mid of 1970s. The aim of this study was to investigate the harvesting of microalgae cells using magnetic microparticles (MPs). Dunaliella tertiolecta was selected as a representative for marine microalgae. The cultivation of microalgae was conducted under continuous artificial light, in 20 L flasks. Iron oxide microparticles were prepared by microwave irradiation of FeSO4 7H2O in an alkaline solution. Samples were taken at different operation intervals to conduct harvesting studies. Batch and flow-through experiments were conducted in order to investigate the effect of the magnetic material on microalgae removal. Algal removal in flow through experiments ranged from 70 to 85% depending on the initial MPs concentration even at very short hydraulic retention times (i.e. 2 min). In batch tests, algal removal was up to 97% at MPs concentration of 490 mg/L.

  17. Insect Cell Culture

    NARCIS (Netherlands)

    Oers, van M.M.; Lynn, D.E.

    2010-01-01

    Insect cell cultures are widely used in studies on insect cell physiology, developmental biology and microbial pathology. In particular, insect cell culture is an indispensable tool for the study of insect viruses. The first continuously growing insect cell cultures were established from lepidoptera

  18. Insect Cell Culture

    NARCIS (Netherlands)

    Oers, van M.M.; Lynn, D.E.

    2010-01-01

    Insect cell cultures are widely used in studies on insect cell physiology, developmental biology and microbial pathology. In particular, insect cell culture is an indispensable tool for the study of insect viruses. The first continuously growing insect cell cultures were established from lepidoptera

  19. Periodic harvesting of embryonic stem cells from a hollow-fiber membrane based four-compartment bioreactor.

    Science.gov (United States)

    Knöspel, Fanny; Freyer, Nora; Stecklum, Maria; Gerlach, Jörg C; Zeilinger, Katrin

    2016-01-01

    Different types of stem cells have been investigated for applications in drug screening and toxicity testing. In order to provide sufficient numbers of cells for such in vitro applications a scale-up of stem cell culture is necessary. Bioreactors for dynamic three-dimensional (3D) culture of growing cells offer the option for culturing large amounts of stem cells at high densities in a closed system. We describe a method for periodic harvesting of pluripotent stem cells (PSC) during expansion in a perfused 3D hollow-fiber membrane bioreactor, using mouse embryonic stem cells (mESC) as a model cell line. A number of 100 × 10(6) mESC were seeded in bioreactors in the presence of mouse embryonic fibroblasts (MEF) as feeder cells. Over a cultivation interval of nine days cells were harvested by trypsin perfusion and mechanical agitation every second to third culture day. A mean of 380 × 10(6) mESC could be removed with every harvest. Subsequent to harvesting, cells continued growing in the bioreactor, as determined by increasing glucose consumption and lactate production. Immunocytochemical staining and mRNA expression analysis of markers for pluripotency and the three germ layers showed a similar expression of most markers in the harvested cells and in mESC control cultures. In conclusion, successful expansion and harvesting of viable mESC from bioreactor cultures with preservation of sterility was shown. The present study is the first one showing the feasibility of periodic harvesting of adherent cells from a continuously perfused four-compartment bioreactor including further cultivation of remaining cells. © 2015 American Institute of Chemical Engineers.

  20. Thermo-responsive poly(N-isopropylacrylamide)-grafted hollow fiber membranes for osteoblasts culture and non-invasive harvest.

    Science.gov (United States)

    Zhuang, Meiling; Liu, Tianqing; Song, Kedong; Ge, Dan; Li, Xiangqin

    2015-10-01

    Hollow fiber membrane (HFM) culture system is one of the most important bioreactors for the large-scale culture and expansion of therapeutic cells. However, enzymatic and mechanical treatments are traditionally applied to harvest the expanded cells from HFMs, which inevitably causes harm to the cells. In this study, thermo-responsive cellulose acetate HFMs for cell culture and non-invasive harvest were prepared for the first time via free radical polymerization in the presence of cerium (IV). ATR-FTIR and elemental analysis results indicated that the poly(N-isopropylacrylamide) (PNIPAAm) was covalently grafted on HFMs successfully. Dynamic contact angle measurements at different temperatures revealed that the magnitude of volume phase transition was decreased with increasing grafted amount of PNIPAAm. And the amount of serum protein adsorbed on HFMs surface also displayed the same pattern. Meanwhile osteoblasts adhered and spread well on the surface of PNIPAAm-grafted HFMs at 37 °C. And Calcein-AM/PI staining, AB assay, ALP activity and OCN protein expression level all showed that PNIPAAm-grafted HFMs had good cell compatibility. After incubation at 20 °C for 120 min, the adhering cells on PNIPAAm-grafted HFMs turned to be round and detached after being gently pipetted. These results suggest that thermo-responsive HFMs are attractive cell culture substrates which enable cell culture, expansion and the recovery without proteolytic enzyme treatment for the application in tissue engineering and regenerative medicine.

  1. Temporal and Spatial Development of Red Deer Harvesting in Europe: Biological and Cultural Factors

    National Research Council Canada - National Science Library

    Jos M. Milner; Christophe Bonenfant; Atle Mysterud; Jean-Michel Gaillard; Sándor Csányi; Nils Chr. Stenseth

    2006-01-01

    1. Deer numbers have increased dramatically throughout Europe and North America over the last century, but empirical analyses of variation in harvesting and the influence of biological and cultural factors are lacking. 2...

  2. Noninvasive photodetachment of stem cells on tunable conductive polymer nano thin films: selective harvesting and preserved differentiation capacity.

    Science.gov (United States)

    You, Jungmok; Heo, June Seok; Kim, Jeonghun; Park, Teahoon; Kim, Byeonggwan; Kim, Han-Soo; Choi, Youjeong; Kim, Hyun Ok; Kim, Eunkyoung

    2013-05-28

    Viable mesenchymal stem cells (MSCs) were efficiently and selectively harvested by near-infrared (NIR) light using the photothermal effect of a conductive polymer nano thin film. The poly(3,4-ethylenedioxy thiophene) (PEDOT)-coated cell culture surfaces were prepared via a simple and fast solution-casting polymerization (SCP) technique. The absorption of PEDOT thin films in the NIR region was effectively triggered cell harvesting upon exposure to an NIR source. By controlling the NIR absorption of the PEDOT film through electrochemical doping or growing PEDOT with different thin film thickness from 70 to 300 nm, the proliferation and harvesting of MSCs on the PEDOT surface were controlled quantitatively. This light-induced cell detachment method based on PEDOT films provides the temporal and spatial control of cell harvesting, as well as cell patterning. The harvested stem cells were found to be alive and well proliferated despite the use of temperature increase by NIR. More importantly, the harvested MSCs by this method preserved their intrinsic characteristics as well as multilineage differentiation capacities. This PEDOT surfaces could be used for repetitive culture and detachment of MSCs or for efficient selection or depletion of a specific subset from heterogeneous population during culture of various tissue-derived cells because there were no photodegradation and photobreakage in the PEDOT films by NIR exposure.

  3. Cell Culture Made Easy.

    Science.gov (United States)

    Dye, Frank J.

    1985-01-01

    Outlines steps to generate cell samples for observation and experimentation. The procedures (which use ordinary laboratory equipment) will establish a short-term primary culture of normal mammalian cells. Information on culture vessels and cell division and a list of questions to generate student interest and involvement in the topics are…

  4. Photoenergy Harvesting Organic PV Cells Using Modified Photosynthetic Light-Harvesting Complex for Energy Harvesting Materials

    Science.gov (United States)

    2008-07-03

    radical cation of the dye sensitizer (Chl  ) blocks the reverse electron transfer from TiO2  and stabilizes the resultant charge-separated state...different kinds of pigments on various electrodes such as TiO2 glass or plastic films (Scheme 3), collaborated with Prof. Minoru Taya, University of...Washinton in Seattle,US (see Time table 2). Scheme 3. Schemetic model of dye sensitized solar cell ( DSSC ) 10 One testable example

  5. Molluscan cells in culture: primary cell cultures and cell lines

    OpenAIRE

    2013-01-01

    In vitro cell culture systems from molluscs have significantly contributed to our basic understanding of complex physiological processes occurring within or between tissue-specific cells, yielding information unattainable using intact animal models. In vitro cultures of neuronal cells from gastropods show how simplified cell models can inform our understanding of complex networks in intact organisms. Primary cell cultures from marine and freshwater bivalve and gastropod species are used as bi...

  6. Thermo-responsive poly(N-isopropylacrylamide)-grafted hollow fiber membranes for osteoblasts culture and non-invasive harvest

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Meiling, E-mail: zhuangmeiling2006@126.com; Liu, Tianqing, E-mail: liutq@dlut.edu.cn; Song, Kedong, E-mail: kedongsong@dlut.edu.cn; Ge, Dan, E-mail: gedan@dlut.edu.cn; Li, Xiangqin, E-mail: xiangqinli@163.com

    2015-10-01

    Hollow fiber membrane (HFM) culture system is one of the most important bioreactors for the large-scale culture and expansion of therapeutic cells. However, enzymatic and mechanical treatments are traditionally applied to harvest the expanded cells from HFMs, which inevitably causes harm to the cells. In this study, thermo-responsive cellulose acetate HFMs for cell culture and non-invasive harvest were prepared for the first time via free radical polymerization in the presence of cerium (IV). ATR-FTIR and elemental analysis results indicated that the poly(N-isopropylacrylamide) (PNIPAAm) was covalently grafted on HFMs successfully. Dynamic contact angle measurements at different temperatures revealed that the magnitude of volume phase transition was decreased with increasing grafted amount of PNIPAAm. And the amount of serum protein adsorbed on HFMs surface also displayed the same pattern. Meanwhile osteoblasts adhered and spread well on the surface of PNIPAAm-grafted HFMs at 37 °C. And Calcein-AM/PI staining, AB assay, ALP activity and OCN protein expression level all showed that PNIPAAm-grafted HFMs had good cell compatibility. After incubation at 20 °C for 120 min, the adhering cells on PNIPAAm-grafted HFMs turned to be round and detached after being gently pipetted. These results suggest that thermo-responsive HFMs are attractive cell culture substrates which enable cell culture, expansion and the recovery without proteolytic enzyme treatment for the application in tissue engineering and regenerative medicine. - Highlights: • PNIPAAm-grafted HFMs exhibited thermoresponsive characteristic. • The OB cells could adhere and spread well on the surface of PNIPAAm-grafted HFMs. • PNIPAAm-grafted HFMs do not significantly impact ALP activity and OCN protein expression level of OB cells. • Cell could be detached from PNIPAAm-grafted HFMs when temperature decreased from 37 °C to 20 °C.

  7. PDADMAC flocculation of Chinese hamster ovary cells: enabling a centrifuge-less harvest process for monoclonal antibodies.

    Science.gov (United States)

    McNerney, Thomas; Thomas, Anne; Senczuk, Anna; Petty, Krista; Zhao, Xiaoyang; Piper, Rob; Carvalho, Juliane; Hammond, Matthew; Sawant, Satin; Bussiere, Jeanine

    2015-01-01

    High titer (>10 g/L) monoclonal antibody (mAb) cell culture processes are typically achieved by maintaining high viable cell densities over longer culture durations. A corresponding increase in the solids and sub-micron cellular debris particle levels are also observed. This higher burden of solids (≥15%) and sub-micron particles typically exceeds the capabilities of a continuous centrifuge to effectively remove the solids without a substantial loss of product and/or the capacity of the harvest filtration train (depth filter followed by membrane filter) used to clarify the centrate. We discuss here the use of a novel and simple two-polymer flocculation method used to harvest mAb from high cell mass cell culture processes. The addition of the polycationic polymer, poly diallyldimethylammonium chloride (PDADMAC) to the cell culture broth flocculates negatively-charged cells and cellular debris via an ionic interaction mechanism. Incorporation of a non-ionic polymer such as polyethylene glycol (PEG) into the PDADMAC flocculation results in larger flocculated particles with faster settling rate compared to PDADMAC-only flocculation. PDADMAC also flocculates the negatively-charged sub-micron particles to produce a feed stream with a significantly higher harvest filter train throughput compared to a typical centrifuged harvest feed stream. Cell culture process variability such as lactate production, cellular debris and cellular densities were investigated to determine the effect on flocculation. Since PDADMAC is cytotoxic, purification process clearance and toxicity assessment were performed.

  8. Mammalian Cell Culture Simplified.

    Science.gov (United States)

    Moss, Robert; Solomon, Sondra

    1991-01-01

    A tissue culture experiment that does not require elaborate equipment and that can be used to teach sterile technique, the principles of animal cell line maintenance, and the concept of cell growth curves is described. The differences between cancerous and normal cells can be highlighted. The procedure is included. (KR)

  9. Fish stem cell cultures.

    Science.gov (United States)

    Hong, Ni; Li, Zhendong; Hong, Yunhan

    2011-04-13

    Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES) cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on "Fish Stem Cells and Nuclear Transfer", we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer.

  10. Fish Stem Cell Cultures

    Directory of Open Access Journals (Sweden)

    Ni Hong, Zhendong Li, Yunhan Hong

    2011-01-01

    Full Text Available Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on “Fish Stem Cells and Nuclear Transfer”, we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer.

  11. Practical energy harvesting for microbial fuel cells: a review.

    Science.gov (United States)

    Wang, Heming; Park, Jae-Do; Ren, Zhiyong Jason

    2015-03-17

    The microbial fuel cell (MFC) technology offers sustainable solutions for distributed power systems and energy positive wastewater treatment, but the generation of practically usable power from MFCs remains a major challenge for system scale up and application. Commonly used external resistors will not harvest any usable energy, so energy-harvesting circuits are needed for real world applications. This review summarizes, explains, and discusses the different energy harvesting methods, components, and systems that can extract and condition the MFC energy for direct utilization. This study aims to assist environmental scientists and engineers to gain fundamental understandings of these electronic systems and algorithms, and it also offers research directions and insights on how to overcome the barriers, so the technology can be further advanced and applied in larger scale.

  12. Intermittent energy harvesting improves the performance of microbial fuel cells.

    Science.gov (United States)

    Dewan, Alim; Beyenal, Haluk; Lewandowski, Zbigniew

    2009-06-15

    In this study, we compare the efficiencies of harvesting energy from microbial fuel cells (MFC) using two modes of operation: (1) continuous-passing the current through an electrical load-and (2) intermittent-first accumulating the energy in a capacitor and then discharging it through the load. Each of these two modes of operation has advantages and disadvantages: the first mode of operation allows the continuous powering of low-power-consuming devices, and the second mode of operation allows the intermittent powering of high-power-consuming devices. We used a two-compartment MFC: in the anodic compartment, Shewanella oneidensis MR-1 was grown using lactate as an electron donor, whereas in the cathodic compartment we used an electrode made of manganese-based catalyzed carbon bonded to a current-collecting screen made of platinum mesh and oxygen as the electron acceptor. The maximum power generated by harvesting energy intermittently was 152 microW, which is 111% higher than the 72 microW generated by harvesting the energy continuously. We conclude that in the operation of MFCs it is beneficial to harvest the energy intermittently. This not only allows the powering of external devices of high power consumption but also allows generating power with greater energy efficiency than does harvesting the energy continuously.

  13. An Investigation of Equine Mesenchymal Stem Cell Characteristics from Different Harvest Sites: More Similar Than Not

    Directory of Open Access Journals (Sweden)

    Karla eLombana

    2015-12-01

    Full Text Available Diseases of the musculoskeletal system are a major cause of loss of use and retirement in sport horses. The use of bone marrow derived mesenchymal stem cells (BMDMSCs for healing of traumatized tissue has gained substantial favor in clinical settings and can assist healing and tissue regeneration in orthopaedic injuries. There are two common sites of harvest of BMDMSCs, the sternum and ilium. Our objective was to determine if any differences exist in BMDMSCs acquired from the sternum and the ilium. We compared the two harvest sites in their propensity to undergo multilineage differentiation, differences in cell surface markers or gene transduction efficiencies.BMDMSCs were isolated and culture-expanded from five mL aspirates of bone marrow from sternum and ilium. The cells were then plated and cultured with appropriate differentiation medium to result in multi-lineage differentiation and cell characteristics were compared between sternal and ilial samples. Cell surface antibody expression of CD11a/18, CD34, CD44 and CD90 were evaluated using flow cytometry and gene transduction efficiencies were evaluated using GFP scAAV. There were no statistically significant differences in cell characteristics between MSCs cultured from sternum and ilium under any circumstances.

  14. Perfusion based cell culture chips

    DEFF Research Database (Denmark)

    Heiskanen, Arto; Emnéus, Jenny; Dufva, Martin

    2010-01-01

    Performing cell culture in miniaturized perfusion chambers gives possibilities to experiment with cells under near in vivo like conditions. In contrast to traditional batch cultures, miniaturized perfusion systems provide precise control of medium composition, long term unattended cultures and ti...

  15. Molluscan cells in culture: primary cell cultures and cell lines.

    Science.gov (United States)

    Yoshino, T P; Bickham, U; Bayne, C J

    2013-06-01

    In vitro cell culture systems from molluscs have significantly contributed to our basic understanding of complex physiological processes occurring within or between tissue-specific cells, yielding information unattainable using intact animal models. In vitro cultures of neuronal cells from gastropods show how simplified cell models can inform our understanding of complex networks in intact organisms. Primary cell cultures from marine and freshwater bivalve and gastropod species are used as biomonitors for environmental contaminants, as models for gene transfer technologies, and for studies of innate immunity and neoplastic disease. Despite efforts to isolate proliferative cell lines from molluscs, the snail Biomphalaria glabrata Say, 1818 embryonic (Bge) cell line is the only existing cell line originating from any molluscan species. Taking an organ systems approach, this review summarizes efforts to establish molluscan cell cultures and describes the varied applications of primary cell cultures in research. Because of the unique status of the Bge cell line, an account is presented of the establishment of this cell line, and of how these cells have contributed to our understanding of snail host-parasite interactions. Finally, we detail the difficulties commonly encountered in efforts to establish cell lines from molluscs and discuss how these difficulties might be overcome.

  16. Semiconductor Nanocrystals as Light Harvesters in Solar Cells

    Directory of Open Access Journals (Sweden)

    Lioz Etgar

    2013-02-01

    Full Text Available Photovoltaic cells use semiconductors to convert sunlight into electrical current and are regarded as a key technology for a sustainable energy supply. Quantum dot-based solar cells have shown great potential as next generation, high performance, low-cost photovoltaics due to the outstanding optoelectronic properties of quantum dots and their multiple exciton generation (MEG capability. This review focuses on QDs as light harvesters in solar cells, including different structures of QD-based solar cells, such as QD heterojunction solar cells, QD-Schottky solar cells, QD-sensitized solar cells and the recent development in organic-inorganic perovskite heterojunction solar cells. Mechanisms, procedures, advantages, disadvantages and the latest results obtained in the field are described. To summarize, a future perspective is offered.

  17. Semiconductor Nanocrystals as Light Harvesters in Solar Cells

    Science.gov (United States)

    Etgar, Lioz

    2013-01-01

    Photovoltaic cells use semiconductors to convert sunlight into electrical current and are regarded as a key technology for a sustainable energy supply. Quantum dot-based solar cells have shown great potential as next generation, high performance, low-cost photovoltaics due to the outstanding optoelectronic properties of quantum dots and their multiple exciton generation (MEG) capability. This review focuses on QDs as light harvesters in solar cells, including different structures of QD-based solar cells, such as QD heterojunction solar cells, QD-Schottky solar cells, QD-sensitized solar cells and the recent development in organic-inorganic perovskite heterojunction solar cells. Mechanisms, procedures, advantages, disadvantages and the latest results obtained in the field are described. To summarize, a future perspective is offered. PMID:28809318

  18. Semiconductor Nanocrystals as Light Harvesters in Solar Cells.

    Science.gov (United States)

    Etgar, Lioz

    2013-02-04

    Photovoltaic cells use semiconductors to convert sunlight into electrical current and are regarded as a key technology for a sustainable energy supply. Quantum dot-based solar cells have shown great potential as next generation, high performance, low-cost photovoltaics due to the outstanding optoelectronic properties of quantum dots and their multiple exciton generation (MEG) capability. This review focuses on QDs as light harvesters in solar cells, including different structures of QD-based solar cells, such as QD heterojunction solar cells, QD-Schottky solar cells, QD-sensitized solar cells and the recent development in organic-inorganic perovskite heterojunction solar cells. Mechanisms, procedures, advantages, disadvantages and the latest results obtained in the field are described. To summarize, a future perspective is offered.

  19. Membrane fouling in microfiltration used for cell harvesting

    Science.gov (United States)

    Kaghazchi, Tahereh; Zokaee, Farzin; Zare, Abbas

    2001-03-01

    In the present study the membrane fouling in microfiltration used for cell harvesting in a deadend system has been investigated. Experimental results were analysed in terms of existing membrane filtration models and membrane resistances. The cake filtration model (CFM) and standard blocking model (SBM) have been considered in this study. Various membrane resistances were determined at different processing time, feed concentration and stirring speed. Resistances to permeation in this system include filter medium, pore blocking, adsorption, cake layer and concentration polarization.

  20. Membrane Fouling in Microfiltration used for Cell Harvesting

    Institute of Scientific and Technical Information of China (English)

    Tahereh Kaghazchi; Farzin Zokaee; Abbas Zare

    2001-01-01

    In the present study the membrane fouling in microfiltration used for cell harvesting in a deadend system has been investigated. Experimental results were analysed in terms of existing membrane filtration models and membrane resistances. The cake filtration model (CFM) and standard blocking model (SBM) have been considered in this study.Various membrane resistances were determined at different processing time, feed concentration and stirring speed. Resistances to permeation in this system include filter medium, pore blocking, adsorption, cake layer and concentration polarization.

  1. An integrated process for microalgae harvesting and cell disruption by the use of ferric ions.

    Science.gov (United States)

    Kim, Dong-Yeon; Oh, You-Kwan; Park, Ji-Yeon; Kim, Bohwa; Choi, Sun-A; Han, Jong-In

    2015-09-01

    In this study, a simultaneous process of harvesting biomass and extracting crude bio-oil was attempted from wet microalgae biomass using FeCl3 and Fe2(SO4)3 as both coagulant and cell-disrupting agent. A culture solution of Chlorella sp. KR-1 was firstly concentrated to 20 g/L and then proceeded for cell disruption with the addition of H2O2. Optimal dosage were 560 and 1060 mg/L for FeCl3 and Fe2(SO4)3, showing harvesting efficiencies of more than 99%. Optimal extraction conditions were identified via the response surface method (RSM), and the extraction yield was almost the same at 120 °C for both iron salts but FAME compositions after transesterification was found to be quite different. Given iron salts were a reference coagulant in water treatment in general and microalgae harvesting in particular, the present approach of using it for harvesting and oil-extraction in a simultaneous manner can serve as a practical route for the microalgae-derived biodiesel production. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Cell Culturing of Cytoskeleton

    Science.gov (United States)

    2004-01-01

    Biomedical research offers hope for a variety of medical problems, from diabetes to the replacement of damaged bone and tissues. Bioreactors, which are used to grow cells and tissue cultures, play a major role in such research and production efforts. Cell culturing, such as this bone cell culture, is an important part of biomedical research. The BioDyn payload includes a tissue engineering investigation. The commercial affiliate, Millenium Biologix, Inc., has been conducting bone implant experiments to better understand how synthetic bone can be used to treat bone-related illnesses and bone damaged in accidents. On STS-95, the BioDyn payload will include a bone cell culture aimed to help develop this commercial synthetic bone product. Millenium Biologix, Inc., is exploring the potential for making human bone implantable materials by seeding its proprietary artificial scaffold material with human bone cells. The product of this tissue engineering experiment using the Bioprocessing Modules (BPMs) on STS-95 is space-grown bone implants, which could have potential for dental implants, long bone grafts, and coating for orthopedic implants such as hip replacements.

  3. Oscillating Cell Culture Bioreactor

    Science.gov (United States)

    Freed, Lisa E.; Cheng, Mingyu; Moretti, Matteo G.

    2010-01-01

    To better exploit the principles of gas transport and mass transport during the processes of cell seeding of 3D scaffolds and in vitro culture of 3D tissue engineered constructs, the oscillatory cell culture bioreactor provides a flow of cell suspensions and culture media directly through a porous 3D scaffold (during cell seeding) and a 3D construct (during subsequent cultivation) within a highly gas-permeable closed-loop tube. This design is simple, modular, and flexible, and its component parts are easy to assemble and operate, and are inexpensive. Chamber volume can be very low, but can be easily scaled up. This innovation is well suited to work with different biological specimens, particularly with cells having high oxygen requirements and/or shear sensitivity, and different scaffold structures and dimensions. The closed-loop changer is highly gas permeable to allow efficient gas exchange during the cell seeding/culturing process. A porous scaffold, which may be seeded with cells, is fixed by means of a scaffold holder to the chamber wall with scaffold/construct orientation with respect to the chamber determined by the geometry of the scaffold holder. A fluid, with/without biological specimens, is added to the chamber such that all, or most, of the air is displaced (i.e., with or without an enclosed air bubble). Motion is applied to the chamber within a controlled environment (e.g., oscillatory motion within a humidified 37 C incubator). Movement of the chamber induces relative motion of the scaffold/construct with respect to the fluid. In case the fluid is a cell suspension, cells will come into contact with the scaffold and eventually adhere to it. Alternatively, cells can be seeded on scaffolds by gel entrapment prior to bioreactor cultivation. Subsequently, the oscillatory cell culture bioreactor will provide efficient gas exchange (i.e., of oxygen and carbon dioxide, as required for viability of metabolically active cells) and controlled levels of fluid

  4. Porcine mitral valve interstitial cells in culture.

    Science.gov (United States)

    Lester, W; Rosenthal, A; Granton, B; Gotlieb, A I

    1988-11-01

    There are connective tissue cells present within the interstitium of the heart valves. This study was designed to isolate and characterize mitral valve interstitial cells from the anterior leaflet of the mitral valve. Explants obtained from the distal part of the leaflet, having been scraped free of surface endocardial cells, were incubated in medium 199 supplemented with 10% fetal bovine serum. Cells grew out of the explant after 3 to 5 days and by 3 weeks these cells were harvested and passaged. Passages 1 to 22 were characterized in several explant sets. The cells showed a growth pattern reminiscent of fibroblasts. Growth was dependent on serum concentration. Cytoskeletal localization of actin and myosin showed prominent stress fibers. Ultrastructural studies showed many elongated cells with prominent stress fibers and some gap junctions and few adherens junctions. There were as well cells with fewer stress fibers containing prominent Golgi complex and dilated endoplasmic reticulum. In the multilayered superconfluent cultures, the former cells tended to be on the substratum of the dish or surface of the multilayered culture, whereas the latter was generally located within the layer of cells. Extracellular matrix was prominent in superconfluent cultures, often within the layers as well. Labeling of the cells with antibody HHF 35 (Tsukada T, Tippens D, Gordon D, Ross R, Gown AM: Am J Pathol 126:51, 1987), which recognizes smooth muscle cell actin, showed prominent staining of the elongated stress fiber-containing cells and much less in the secretory type cells. These studies show that interstitial mitral valve cells can be grown in culture and that either two different cell types or one cell type with two phenotypic expressions is present in culture.

  5. Perfusion Based Cell Culture Chips

    Science.gov (United States)

    Heiskanen, A.; Emnéus, J.; Dufva, M.

    Performing cell culture in miniaturized perfusion chambers gives possibilities to experiment with cells under near in vivo like conditions. In contrast to traditional batch cultures, miniaturized perfusion systems provide precise control of medium composition, long term unattended cultures and tissue like structuring of the cultures. However, as this chapter illustrates, many issues remain to be identified regarding perfusion cell culture such as design, material choice and how to use these systems before they will be widespread amongst biomedical researchers.

  6. Perfusion based cell culture chips

    DEFF Research Database (Denmark)

    Heiskanen, Arto; Emnéus, Jenny; Dufva, Martin

    2010-01-01

    and tissue like structuring of the cultures. However, as this chapter illustrates, many issues remain to be identified regarding perfusion cell culture such as design, material choice and how to use these systems before they will be widespread amongst biomedical researchers.......Performing cell culture in miniaturized perfusion chambers gives possibilities to experiment with cells under near in vivo like conditions. In contrast to traditional batch cultures, miniaturized perfusion systems provide precise control of medium composition, long term unattended cultures...

  7. Harvesting, processing and inventory management of peripheral blood stem cells

    Directory of Open Access Journals (Sweden)

    Mijovic Aleksandar

    2007-01-01

    Full Text Available By 2003, 97% autologous transplants and 65% of allogeneic transplants in Europe used mobilised peripheral blood stem cells (PBSC. Soon after their introduction in the early 1990′s, PBSC were associated with faster haemopoietic recovery, fewer transfusions and antibiotic usage, and a shorter hospital stay. Furthermore, ease and convenience of PBSC collection made them more appealing than BM harvests. Improved survival has hitherto been demonstrated in patients with high risk AML and CML. However, the advantages of PBSC come at a price of a higher incidence of extensive chronic GVHD. In order to be present in the blood, stem cells undergo the process of "mobilisation" from their bone marrow habitat. Mobilisation, and its reciprocal process - homing - are regulated by a complex network of molecules on the surface of stem cells and stromal cells, and enzymes and cytokines released from granulocytes and osteoclasts. Knowledge of these mechanisms is beginning to be exploited for clinical purposes. In current practice, stem cell are mobilised by use of chemotherapy in conjunction with haemopoietic growth factors (HGF, or with HGF alone. Granulocyte colony stimulating factor has emerged as the single most important mobilising agent, due to its efficacy and a relative paucity of serious side effects. Over a decade of use in healthy donors has resulted in vast experience of optimal dosing and administration, and safety matters. PBSC harvesting can be performed on a variety of cell separators. Apheresis procedures are nowadays routine, but it is important to be well versed in the possible complications in order to avoid harm to the patient or donor. To ensure efficient collection, harvesting must begin when sufficient stem cells have been mobilised. A rapid, reliable, standardized blood test is essential to decide when to begin harvesting; currently, blood CD34+ cell counting by flow cytometry fulfils these criteria. Blood CD34+ cell counts strongly

  8. Microfluidic Cell Culture Device

    Science.gov (United States)

    Takayama, Shuichi (Inventor); Cabrera, Lourdes Marcella (Inventor); Heo, Yun Seok (Inventor); Smith, Gary Daniel (Inventor)

    2014-01-01

    Microfluidic devices for cell culturing and methods for using the same are disclosed. One device includes a substrate and membrane. The substrate includes a reservoir in fluid communication with a passage. A bio-compatible fluid may be added to the reservoir and passage. The reservoir is configured to receive and retain at least a portion of a cell mass. The membrane acts as a barrier to evaporation of the bio-compatible fluid from the passage. A cover fluid may be added to cover the bio-compatible fluid to prevent evaporation of the bio-compatible fluid.

  9. Green grasses as light harvesters in dye sensitized solar cells

    Science.gov (United States)

    Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A.; Anandan, Sambandam; Murugan, Ramaswamy

    2015-01-01

    Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a).

  10. Improvement of Pyroelectric Cells for Thermal Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Jing-Chih Ciou

    2012-01-01

    Full Text Available This study proposes trenching piezoelectric (PZT material in a thicker PZT pyroelectric cell to improve the temperature variation rate to enhance the efficiency of thermal energy-harvesting conversion by pyroelectricity. A thicker pyroelectric cell is beneficial in generating electricity pyroelectrically, but it hinders rapid temperature variations. Therefore, the PZT sheet was fabricated to produce deeper trenches to cause lateral temperature gradients induced by the trenched electrode, enhancing the temperature variation rate under homogeneous heat irradiation. When the trenched electrode type with an electrode width of 200 μm and a cutting depth of 150 μm was used to fabricate a PZT pyroelectric cell with a 200 μm thick PZT sheet, the temperature variation rate was improved by about 55%. Therefore, the trenched electrode design did indeed enhance the temperature variation rate and the efficiency of pyroelectric energy converters.

  11. High efficiency nanostructured thin film solar cells for energy harvesting

    Science.gov (United States)

    Welser, Roger E.; Sood, Ashok K.; Lewis, Jay S.; Dhar, Nibir K.; Wijewarnasuriya, Priyalal S.

    2016-05-01

    Thin-film III-V materials are an attractive candidate material for solar energy harvesting devices capable of supplying portable and mobile power in both terrestrial and space environments. Nanostructured quantum well and quantum dot solar cells are being widely investigated as a means of extending infrared absorption and enhancing photovoltaic device performance. In this paper, we will review recent progress on realizing high-voltage InGaAs/GaAs quantum well solar cells that operate at or near the radiative limit of performance. These high-voltage nanostructured device designs provide a pathway to enhance the performance of existing device technologies, and can also be leveraged for next-generation solar cells.

  12. Cell culture's spider silk road.

    Science.gov (United States)

    Perkel, Jeffrey

    2014-06-01

    A number of synthetic and natural materials have been tried in cell culture and tissue engineering applications in recent years. Now Jeffrey Perkel takes a look at one new culture component that might surprise you-spider silk.

  13. Maximizing photosynthetic efficiency and culture productivity in cyanobacteria upon minimizing the phycobilisome light-harvesting antenna size.

    Science.gov (United States)

    Kirst, Henning; Formighieri, Cinzia; Melis, Anastasios

    2014-10-01

    A phycocyanin-deletion mutant of Synechocystis (cyanobacteria) was generated upon replacement of the CPC-operon with a kanamycin resistance cassette. The Δcpc transformant strains (Δcpc) exhibited a green phenotype, compared to the blue-green of the wild type (WT), lacked the distinct phycocyanin absorbance at 625nm, and had a lower Chl per cell content and a lower PSI/PSII reaction center ratio compared to the WT. Molecular and genetic analyses showed replacement of all WT copies of the Synechocystis DNA with the transgenic version, thereby achieving genomic DNA homoplasmy. Biochemical analyses showed the absence of the phycocyanin α- and β-subunits, and the overexpression of the kanamycin resistance NPTI protein in the Δcpc. Physiological analyses revealed a higher, by a factor of about 2, intensity for the saturation of photosynthesis in the Δcpc compared to the WT. Under limiting intensities of illumination, growth of the Δcpc was slower than that of the WT. This difference in the rate of cell duplication diminished gradually as growth irradiance increased. Identical rates of cell duplication of about 13h for both WT and Δcpc were observed at about 800μmolphotonsm(-2)s(-1) or greater. Culture productivity analyses under simulated bright sunlight and high cell-density conditions showed that biomass accumulation by the Δcpc was 1.57-times greater than that achieved by the WT. Thus, the work provides first-time direct evidence of the applicability of the Truncated Light-harvesting Antenna (TLA)-concept in cyanobacteria, entailing substantial improvements in the photosynthetic efficiency and productivity of mass cultures upon minimizing the phycobilisome light-harvesting antenna size.

  14. Cell culture density affects the stemness gene expression of adipose tissue-derived mesenchymal stem cells.

    Science.gov (United States)

    Kim, Dae Seong; Lee, Myoung Woo; Lee, Tae-Hee; Sung, Ki Woong; Koo, Hong Hoe; Yoo, Keon Hee

    2017-03-01

    The results of clinical trials using mesenchymal stem cells (MSCs) are controversial due to the heterogeneity of human MSCs and differences in culture conditions. In this regard, it is important to identify gene expression patterns according to culture conditions, and to determine how the cells are expanded and when they should be clinically used. In the current study, stemness gene expression was investigated in adipose tissue-derived MSCs (AT-MSCs) harvested following culture at different densities. AT-MSCs were plated at a density of 200 or 5,000 cells/cm(2). After 7 days of culture, stemness gene expression was examined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis. The proliferation rate of AT-MSCs harvested at a low density (~50% confluent) was higher than that of AT-MSCs harvested at a high density (~90% confluent). Although there were differences in the expression levels of stemness gene, such as octamer-binding transcription factor 4, nanog homeobox (Nanog), SRY-box 2, Kruppel like factor 4, v-myc avian myelocytomatosis viral oncogene homolog (c-Myc), and lin-28 homolog A, in the AT-MSCs obtained from different donors, RT-qPCR analysis demonstrated differential gene expression patterns according to the cell culture density. Expression levels of stemness genes, particularly Nanog and c-Myc, were upregulated in AT-MSCs harvested at a low density (~50% confluent) in comparison to AT-MSCs from the same donor harvested at a high density (~90% confluent). These results imply that culture conditions, such as the cell density at harvesting, modulate the stemness gene expression and proliferation of MSCs.

  15. Interpretation of cell culture phenomena.

    Science.gov (United States)

    Vierck, J L; Dodson, M V

    2000-03-01

    This paper discusses the dilemma of interpreting unusual or abnormal phenomena seen in cell cultures and is not intended to address the statistical design of experiments. Problems that can be encountered when growing cells in experimental situations include low or decreasing cell numbers, abnormal cell morphology, microbial contamination, and detachment of the cell monolayer. If any of these situations occur, it is not realistic to proceed with data analysis until the problem is corrected. The best policy is to attempt to standardize all types of cultures used for analysis and to avoid using any cultures that display atypical characteristics.

  16. GreenDelivery: Proactive Content Caching and Push with Energy-Harvesting-based Small Cells

    OpenAIRE

    Zhou, Sheng; Gong, Jie; ZHOU, Zhenyu; Chen, Wei; Niu, Zhisheng

    2015-01-01

    The explosive growth of mobile multimedia traffic calls for scalable wireless access with high quality of service and low energy cost. Motivated by the emerging energy harvesting communications, and the trend of caching multimedia contents at the access edge and user terminals, we propose a paradigm-shift framework, namely GreenDelivery, enabling efficient content delivery with energy harvesting based small cells. To resolve the two-dimensional randomness of energy harvesting and content requ...

  17. Flexible hybrid energy cell for simultaneously harvesting thermal, mechanical, and solar energies.

    Science.gov (United States)

    Yang, Ya; Zhang, Hulin; Zhu, Guang; Lee, Sangmin; Lin, Zong-Hong; Wang, Zhong Lin

    2013-01-22

    We report the first flexible hybrid energy cell that is capable of simultaneously or individually harvesting thermal, mechanical, and solar energies to power some electronic devices. For having both the pyroelectric and piezoelectric properties, a polarized poly(vinylidene fluoride) (PVDF) film-based nanogenerator (NG) was used to harvest thermal and mechanical energies. Using aligned ZnO nanowire arrays grown on the flexible polyester (PET) substrate, a ZnO-poly(3-hexylthiophene) (P3HT) heterojunction solar cell was designed for harvesting solar energy. By integrating the NGs and the solar cells, a hybrid energy cell was fabricated to simultaneously harvest three different types of energies. With the use of a Li-ion battery as the energy storage, the harvested energy can drive four red light-emitting diodes (LEDs).

  18. Optimization of Chlorella vulgaris and bioflocculant-producing bacteria co-culture: enhancing microalgae harvesting and lipid content.

    Science.gov (United States)

    Wang, Y; Yang, Y; Ma, F; Xuan, L; Xu, Y; Huo, H; Zhou, D; Dong, S

    2015-05-01

    Microalgae are a sustainable bioresource, and the biofuel they produce is widely considered to be an alternative to limited natural fuel resources. However, microalgae harvesting is a bottleneck in the development of technology. Axenic Chlorella vulgaris microalgae exhibit poor harvesting, as expressed by a flocculation efficiency of 0·2%. This work optimized the co-culture conditions of C. vulgaris and bioflocculant-producing bacteria in synthetic wastewater using response surface methodology (RSM), thus aiming to enhance C. vulgaris harvesting and lipid content. Three significant process variables- inoculation ratio of bacteria and microalgae, initial glucose concentration, and co-culture time- were proposed in the RSM model. F-values (3·98/8·46) and R(2) values (0·7817/0·8711) both indicated a reasonable prediction by the RSM model. The results showed that C. vulgaris harvesting efficiency reached 45·0-50·0%, and the lipid content was over 21·0% when co-cultured with bioflocculant-producing bacteria under the optimized culture conditions of inoculation ratio of bacteria and microalgae of 0·20-0·25, initial glucose concentration of microalgae harvesting and cost-effective microalgal bioproducts, and confirmed the promising prospect of introducing bioflocculant-producing bacteria into microalgae bioenergy production. This work optimized the co-culture conditions of microalgae (C. vulgaris) and bioflocculant-producing bacteria (F2, Rhizobium radiobacter) in synthetic wastewater using response surface methodology, aiming to enhance C. vulgaris harvesting and lipid produced content. Bioflocculant-producing microbes are environmentally friendly functional materials. They avoid the negative effects of traditional chemical flocculants. This work provided new insights into microalgae harvesting and cost-effective production of microalgal bioproducts, and confirmed the promising prospect of introducing bioflocculant-producing bacteria into microalgae

  19. Characterization of a novel miniature cell culture device

    Science.gov (United States)

    Moore, Sandra K.; Kleis, Stanley J.

    2008-05-01

    Recent advancements in the field of microfluidics have generated much interest in the advent of a miniaturized cell culture device. In this study, we developed a novel miniature culture system (cells, either prokaryotic or eukaryotic in type, for both 1 g and microgravity applications. The miniature culture system may advance the development of microanalytical remote monitoring tools such as biological sentinels, biosensors, and lab-on-a-chip. Integrating the autonomous miniature culture system with a microanalytical device makes a powerful biological tool. Cells can be cultured long-term, harvested, and released directly into an analytical tool without the need for human interaction through fluid dynamic manipulations. This work characterizes the miniature bioreactor system through numerical and experimental proof of concept studies.

  20. Light harvesting via energy transfer in the dye solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Siegers, Conrad

    2007-11-09

    The PhD-thesis ''Light Harvesting via Energy Transfer in the Dye Solar Cell'' (University of Freiburg, July 2007) describes the conceptual design, synthesis and testing of energy donor acceptor sensitizers for the dye solar cell (DSC). Under monochromatic illumination solar cells sensitized with the novel donor acceptor systems revealed a higher power conversion efficiency than cells containing exclusively the acceptor component. The following approach led to this conclusion: (i) the choice of suitable chromophores as energy donor and acceptor moieties according to the Foerster-theory, (ii) the synthesis of different donor acceptor systems, (iii) the development of a methodology allowing the quantification of energy transfer within dye solar cells, and (iv) the evaluation of characteristics of DSCs that were sensitized with the different donor acceptor systems. The acceptor chromophores used in this work were derived from [Ru(dcbpy)2acac]Cl (dcbpy = 4,4'-dicarboxy-2,2'-bipyridin, acac = acetylacetonato). This complex offered the opportunity to introduce substituents at the acac-ligand's terminal CH3 groups without significantly affecting its excellent photoelectrochemical properties. Alkylated 4-amino-1,8-naphthalimides (termed Fluorols in the following) were used as energy donor chromophores. This class of compounds fulfils the requirements for efficient energy transfer to [Ru(dcbpy)2acac]Cl. Covalently linking donor and acceptor chromophores to one another was achieved by two different concepts. A dyad comprising one donor and one acceptor chromophore was synthesized by subsequent hydrosilylation steps of an olefin-bearing donor and an acceptor precursor to the dihydrosilane HSiMe2-CH2CH2-SiMe2H. A series of polymers comprising multiple donor and acceptor units was made by the addition of alkyne-bearing chromophores to hyperbranched polyglycerol azide (''Click-chemistry''). In this series the donor acceptor

  1. Light harvesting via energy transfer in the dye solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Siegers, Conrad

    2007-11-09

    The PhD-thesis ''Light Harvesting via Energy Transfer in the Dye Solar Cell'' (University of Freiburg, July 2007) describes the conceptual design, synthesis and testing of energy donor acceptor sensitizers for the dye solar cell (DSC). Under monochromatic illumination solar cells sensitized with the novel donor acceptor systems revealed a higher power conversion efficiency than cells containing exclusively the acceptor component. The following approach led to this conclusion: (i) the choice of suitable chromophores as energy donor and acceptor moieties according to the Foerster-theory, (ii) the synthesis of different donor acceptor systems, (iii) the development of a methodology allowing the quantification of energy transfer within dye solar cells, and (iv) the evaluation of characteristics of DSCs that were sensitized with the different donor acceptor systems. The acceptor chromophores used in this work were derived from [Ru(dcbpy)2acac]Cl (dcbpy = 4,4'-dicarboxy-2,2'-bipyridin, acac = acetylacetonato). This complex offered the opportunity to introduce substituents at the acac-ligand's terminal CH3 groups without significantly affecting its excellent photoelectrochemical properties. Alkylated 4-amino-1,8-naphthalimides (termed Fluorols in the following) were used as energy donor chromophores. This class of compounds fulfils the requirements for efficient energy transfer to [Ru(dcbpy)2acac]Cl. Covalently linking donor and acceptor chromophores to one another was achieved by two different concepts. A dyad comprising one donor and one acceptor chromophore was synthesized by subsequent hydrosilylation steps of an olefin-bearing donor and an acceptor precursor to the dihydrosilane HSiMe2-CH2CH2-SiMe2H. A series of polymers comprising multiple donor and acceptor units was made by the addition of alkyne-bearing chromophores to hyperbranched polyglycerol azide (''Click-chemistry''). In this series the donor acceptor

  2. Evaluation of predictive tools for cell culture clarification performance.

    Science.gov (United States)

    Senczuk, Anna; Petty, Krista; Thomas, Anne; McNerney, Thomas; Moscariello, John; Yigzaw, Yinges

    2016-03-01

    Recent advances in the productivity of industrial mammalian cell culture processes have resulted in part in increased cell density. This increase and the associated increase in cellular debris are known to challenge harvest operations, however this understanding is limited and largely qualitative. Part of the issue arises from the heterogeneous size and composition of cellular debris, which makes harvest feed stream extremely difficult to characterize. Improved characterization methods would facilitate the development of clarification approaches that are consistent and scalable. This work describes how both particle size and cholesterol analysis can be used to characterize the feed stream. Particle size analysis by focused beam reflectance and dynamic light scattering are shown to be predictive of centrate filterability under certain harvest conditions. Because of the particle size range limitations of each detector, their applicability is limited to a particular stage or method of clarification. The measurement of cholesterol present in the cell culture supernatant or centrate was successfully used in providing relative amount of lysed cellular debris and enabled us to predict clarification performance of acid precipitated harvest regardless of particle size distribution profile. © 2015 Wiley Periodicals, Inc.

  3. Cell culture purity issues and DFAT cells

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Shengjuan [College of Animal Science and Technology, Northwest A and F University, Yangling, Shaanxi Province 712100 (China); Department of Animal Sciences, Washington State University, Pullman, WA 99164 (United States); Bergen, Werner G. [Program in Cellular and Molecular Biosciences/Department of Animal Sciences, Auburn University, Auburn, AL 36849 (United States); Hausman, Gary J. [Animal Science Department, University of Georgia, Athens, GA 30602-2771 (United States); Zan, Linsen, E-mail: zanls@yahoo.com.cn [College of Animal Science and Technology, Northwest A and F University, Yangling, Shaanxi Province 712100 (China); Dodson, Michael V., E-mail: dodson@wsu.edu [Department of Animal Sciences, Washington State University, Pullman, WA 99164 (United States)

    2013-04-12

    Highlights: •DFAT cells are progeny cells derived from dedifferentiated mature adipocytes. •Common problems in this research is potential cell contamination of initial cultures. •The initial cell culture purity is crucial in DFAT cell research field. -- Abstract: Dedifferentiation of mature adipocytes, in vitro, has been pursued/documented for over forty years. The subsequent progeny cells are named dedifferentiated adipocyte-derived progeny cells (DFAT cells). DFAT cells are proliferative and likely to possess mutilineage potential. As a consequence, DFAT cells and their progeny/daughter cells may be useful as a potential tool for various aspects of tissue engineering and as potential vectors for the alleviation of several disease states. Publications in this area have been increasing annually, but the purity of the initial culture of mature adipocytes has seldom been documented. Consequently, it is not always clear whether DFAT cells are derived from dedifferentiated mature (lipid filled) adipocytes or from contaminating cells that reside in an impure culture.

  4. Cell culture purity issues and DFAT cells.

    Science.gov (United States)

    Wei, Shengjuan; Bergen, Werner G; Hausman, Gary J; Zan, Linsen; Dodson, Michael V

    2013-04-12

    Dedifferentiation of mature adipocytes, in vitro, has been pursued/documented for over forty years. The subsequent progeny cells are named dedifferentiated adipocyte-derived progeny cells (DFAT cells). DFAT cells are proliferative and likely to possess mutilineage potential. As a consequence, DFAT cells and their progeny/daughter cells may be useful as a potential tool for various aspects of tissue engineering and as potential vectors for the alleviation of several disease states. Publications in this area have been increasing annually, but the purity of the initial culture of mature adipocytes has seldom been documented. Consequently, it is not always clear whether DFAT cells are derived from dedifferentiated mature (lipid filled) adipocytes or from contaminating cells that reside in an impure culture.

  5. Fine needle aspiration biopsy to reestablish cell culture in an animal model of uveal melanoma.

    Science.gov (United States)

    Correa, Zelia Maria da Silva; Marshall, Jean-Claude; Souza Filho, João Pessoa; Odashiro, Alexandre Nakao; Burnier Jr, Miguel Noel

    2009-01-01

    To access the reliability of fine-needle aspiration biopsy in harvesting a sufficient amount of viable melanoma cells to establish a cell culture and maintain a melanoma cell line from an animal model of uveal melanoma. For this study, fifteen male New Zealand albino rabbits had their right eye surgically inoculated with uveal melanoma cell line 92.1. The animals were immunosupressed with cyclosporine A using a dose schedule previously published. The animals were followed for 12 weeks. Intraocular tumor growth was monitored weekly by indirect ophthalmoscopy. After the fourth week, one animal was sacrificed per week preceded by fine-needle aspiration biopsy using a sharp 25-gauge, 1-inch long needle. Two separate aspirates were made from different areas of the tumor. Each aspirate was flushed to a separate cell culture media and sent for cell culture. The cells were frozen after two weeks when there were at least 1 million cells, which is enough to maintain a cell line. Cells were defrosted for HMB-45 immuno-stains to confirm the melanoma origin. Cell growth was observed from the samples harvested from 11 out of the 15 animals inoculated with uveal melanoma. All cell cultures, after defrost, immunoassayed positive for HMB-45. Fine needle aspiration biopsy seems to be a reliable method to harvest cells from solid intraocular melanomas in an animal model, to establish cell culture and to maintain a melanoma cell line.

  6. Harvesting of Chlorella sorokiniana by co-culture with the filamentous fungus Isaria fumosorosea: A potential sustainable feedstock for hydrothermal gasification.

    Science.gov (United States)

    Mackay, Stephen; Gomes, Eduardo; Holliger, Christof; Bauer, Rolene; Schwitzguébel, Jean-Paul

    2015-06-01

    Despite recent advances in down-stream processing, production of microalgae remains substantially limited because of economical reasons. Harvesting and dewatering are the most energy-intensive processing steps in their production and contribute 20-30% of total operational cost. Bio-flocculation of microalgae by co-cultivation with filamentous fungi relies on the development of large structures that facilitate cost effective harvesting. A yet unknown filamentous fungus was isolated as a contaminant from a microalgal culture and identified as Isaria fumosorosea. Blastospores production was optimized in minimal medium and the development of pellets, possibly lichens, was followed when co-cultured with Chlorella sorokiniana under strict autotrophic conditions. Stable pellets (1-2mm) formed rapidly at pH 7-8, clearing the medium of free algal cells. Biomass was harvested with large inexpensive filters, generating wet slurry suitable for hydrothermal gasification. Nutrient rich brine from the aqueous phase of hydrothermal gasification supported growth of the fungus and may increase the process sustainability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Fabrication of a Novel Cell Culture System Using DNA-Grafted Substrates and DNase.

    Science.gov (United States)

    Mitomo, Hideyuki; Eguchi, Asumi; Suzuki, Yasunobu; Matsuo, Yasutaka; Niikura, Kenichi; Nakazawa, Kohji; Ijiro, Kuniharu

    2016-02-01

    In conventional cell culture systems, trypsin is generally used for cell harvesting. However, trypsin damages the cells due to the nonselective degradation of proteins on the cell surface. This is a critical issue for cell culture systems. Therefore, an alternative cell culture system with the lowest possible impact on cells is desired. In this paper, we have focused on DNA as a sacrificial layer and DNase as an alternate enzyme instead of trypsin. DNase ought not to result in damage to or stress on cells as it only hydrolyzes DNAs while the plasma membrane and extracellular matrices are basically composed of lipids, proteins, and glycosides. Therefore, we fabricated DNA-grafted substrates as cell culture dishes and evaluated this novel cell culture system. As a result, we were able to culture several types of mammalian cells on the DNA-grafted substrates, with the cells harvested using DNase with only little damage to the cells. This cell culture system could provide a breakthrough in cell culturing technology.

  8. Harvesting multipotent progenitor cells from a small sample of tonsillar biopsy for clinical applications.

    Science.gov (United States)

    Khatri, Raju; Arad, Michal; Ortlip, Timothy; Portney, Benjamin A; Meltzer, W Alex; Diaconu, Silviu; Silipino, Lorna E; Wang, Ying; Kaetzel, David M; Taylor, Rodney J; Zalzman, Michal

    2017-07-27

    Human adult stem cells hold the potential for the cure of numerous conditions and degenerative diseases. They possess major advantages over pluripotent stem cells as they can be derived from donors at any age, and therefore pose no ethical concerns or risk of teratoma tumor formation in vivo. Furthermore, they have a natural ability to differentiate and secrete factors that promote tissue healing without genetic manipulation. However, at present, clinical applications of adult stem cells are limited by a shortage of a reliable, standardized, and easily accessible tissue source which does not rely on specimens discarded from unrelated surgical procedures. Human tonsil-derived mesenchymal progenitor cells (MPCs) were isolated from a small sample of tonsillar tissue (average 0.88 cm(3)). Our novel procedure poses a minimal mechanical and enzymatic insult to the tissue, and therefore leads to high cell viability and yield. We characterized these MPCs and demonstrated robust multipotency in vitro. We further show that these cells can be propagated and maintained in xeno-free conditions. We have generated tonsillar biopsy-derived MPC (T-MPC) lines from multiple donors across a spectrum of age, sex, and race, and successfully expanded them in culture. We characterized them by cell surface markers, as well as in vitro expansion and differentiation potential. Our procedure provides a robust yield of tonsillar biopsy-derived T-MPCs. Millions of MPCs can be harvested from a sample smaller than 1 g, which can be collected from a fully awake donor in an outpatient setting without the need for general anesthesia or hospitalization. Our study identifies tonsillar biopsy as an abundant source of adult MPCs for regenerative medicine.

  9. Cell culture compositions

    Science.gov (United States)

    Dunn-Coleman, Nigel; Goedegebuur, Frits; Ward, Michael; Yiao, Jian

    2014-03-18

    The present invention provides a novel endoglucanase nucleic acid sequence, designated egl6 (SEQ ID NO:1 encodes the full length endoglucanase; SEQ ID NO:4 encodes the mature form), and the corresponding endoglucanase VI amino acid sequence ("EGVI"; SEQ ID NO:3 is the signal sequence; SEQ ID NO:2 is the mature sequence). The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding EGVI, recombinant EGVI proteins and methods for producing the same.

  10. Compact hybrid cell based on a convoluted nanowire structure for harvesting solar and mechanical energy

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Chen; Wang, Zhong Lin [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2011-02-15

    A fully integrated, solid-state, compact hybrid cell (CHC) that comprises ''convoluted'' ZnO nanowire structures for concurrent harvesting of both solar and mechanical energy is demonstrated. The compact hybrid cell is based on a conjunction design of an organic solid-state dye-sensitized solar cell (DSSC) and piezoelectric nanogenerator in one compact structure. The CHC shows a significant increase in output power, clearly demonstrating its potential for simultaneously harvesting multiple types of energy for powering small electronic devices for independent, sustainable, and mobile operation. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Efficient Light Harvester Layer Prepared by Solid/Mist Interface Reaction for Perovskite Solar Cells.

    Science.gov (United States)

    Xia, Xiang; Li, Hongcui; Wu, Wenyi; Li, Yanhua; Fei, Dehou; Gao, Chunxiao; Liu, Xizhe

    2015-08-12

    A solid/mist reaction method is developed to produce well-crystallized light harvester layers without pinhole defects for perovskite solar cells. The reaction based on mist precursor can be facilely operated with low process temperature. And it can effectively control the volume of CH3NH3I solution and the reaction temperature, which affect the quality of perovskite harvester layers and the performance of perovskite solar cells remarkably. Under optimized condition, the efficiencies of devices reach 16.2% with the average efficiency of 14.9%. The solid/mist reaction is also used to fabricate planar junction solar cells and a PCE of 14.9% is obtained.

  12. Insect Cell Culture and Biotechnology

    Institute of Scientific and Technical Information of China (English)

    Robert R.Granados; Guoxun Li; G.W.Blissard

    2007-01-01

    The continued development of new cell culture technology is essential for the future growth and application of insect cell and baculovirus biotechnology. The use of cell lines for academic research and for commercial applications is currently dominated by two cell lines; the Spodoptera frugiperda line, SF21 (and its clonal isolate, SF9), and the Trichoplusia ni line, BTI 5B1-4, commercially known as High Five cells. The long perceived prediction that the immense potential application of the baculovirus-insect cell system, as a tool in cell and molecular biology, agriculture, and animal health, has been achieved. The versatility and recent applications of this popular expression system has been demonstrated by both academia and industry and it is clear that this cell-based system has been widely accepted for biotechnological applications. Numerous small to midsize startup biotechnology companies in North America and the Europe are currently using the baculovirus-insect cell technology to produce custom recombinant proteins for research and commercial applications. The recent breakthroughs using the baculovirus-insect cell-based system for the development of several commercial products that will impact animal and human health will further enhance interest in this technology by pharma. Clearly, future progress in novel cell and engineering advances will lead to fundamental scientific discoveries and serve to enhance the utility and applications of this baculovirus-insect cell system.

  13. Biological control of post-harvest diseases on apple by using plant essential oils and Trichoderma culture filtrates

    OpenAIRE

    2013-01-01

    Pure essential oils have been purified and chemically characterized from cinnamon, clove and black pepper. All these oils have antifungal properties and when applied to apple fruits in post harvest can efficiently control Botrytis cinerea, Alternaria alternata or Penicillium expansum. In addition, application of these compounds or Trichoderma culture filtrate can induce systemic resistance mechanisms in apple fruit. This has been confirmed through phytoalexins and proteomic analysis. The accu...

  14. Peripheral blood stem cell harvest in patients with limited stage small-cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Katakami, Nobuyuki; Takakura, Shunji; Fujii, Hiroshi; Nishimura, Takashi; Umeda, Bunichi [Kobe City General Hospital (Japan)

    2000-06-01

    Chemotherapy plus granulocyte colony-stimulating factor (G-CSF) induced mobilization of peripheral blood stem cells (PBSC) was performed in patients with limited stage small-cell lung cancer. Chemotherapy consisted of cisplatin/etoposide or cisplatin/adriamycin/etoposide. The amounts of CD34 positive cells and granulocyte-macrophage colony forming units (CFU-GM) collected during 2-3 courses of apheresis were 3.1{+-}2.9 x 10{sup 6}/kg (n=10) and 3.1{+-}1.5 x 10{sup 5}/kg (n=8) , respectively. Adequate amounts of PBSC were also harvested even in patients treated with concurrent chemoradiotherapy. Eight patients were successfully treated with high-dose chemotherapy consisting of ifosfamide, carboplatin and etoposide with PBSC transfusion. The patients'-bone marrow reconstruction was rapid and no treatment-related death was observed. (author)

  15. 9 CFR 101.6 - Cell cultures.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cell cultures. 101.6 Section 101.6..., SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS DEFINITIONS § 101.6 Cell cultures. When used in conjunction with or in reference to cell cultures, which may be referred to as tissue...

  16. Self-assembled photosynthesis-inspired light harvesting material and solar cells containing the same

    Science.gov (United States)

    Lindsey, Jonathan S.; Chinnasamy, Muthiah; Fan, Dazhong

    2009-12-15

    A solar cell is described that comprises: (a) a semiconductor charge separation material; (b) at least one electrode connected to the charge separation material; and (c) a light-harvesting film on the charge separation material, the light-harvesting film comprising non-covalently coupled, self-assembled units of porphyrinic macrocycles. The porphyrinic macrocycles preferably comprise: (i) an intramolecularly coordinated metal; (ii) a first coordinating substituent; and (iii) a second coordinating substituent opposite the first coordinating substituent. The porphyrinic macrocycles can be assembled by repeating intermolecular coordination complexes of the metal, the first coordinating substituent and the second coordinating substituent.

  17. Enhanced Light Harvesting in Dye-Sensitized Solar Cell Using External Lightguide

    Directory of Open Access Journals (Sweden)

    Chi-Hui Chien

    2011-01-01

    Full Text Available An external lightguide (EL for enhancing the light-harvesting efficiency of dye-sensitized solar cells (DSSCs was designed and developed. The EL attached to the exterior of a DSSC photoelectrode directed light on a dye-covered nanoporous TiO2 film (D-NTF of the photoelectrode. Experimental tests confirmed that the EL increased the light-harvesting efficiency of a DSSC with an active area of 0.25 cm2 by 30.69%. Photocurrent density and the power conversion efficiency were also increased by 38.12% and 25.09%, respectively.

  18. Influvac: a safe Madin Darby Canine Kidney (MDCK) cell culture-based influenza vaccine.

    Science.gov (United States)

    Brands, R; Visser, J; Medema, J; Palache, A M; van Scharrenburg, G J

    1999-01-01

    Influenza vaccine production technology based on large scale cell culture technology has been developed. From the characterization of the continuous cell line MDCK as well as drug safety studies we conclude that this cell line and the cell culture system are suitable for biological production. The Down Stream Process (DSP) of the virus-containing harvest fluids guarantees sufficient inactivation of influenza viruses and adequate removal or inactivation of putative adventitious or endogenous viruses, mycoplasma or bacteria. Our data indicate that the tissue culture-based production technology is feasible.

  19. Fine needle aspiration biopsy to reestablish cell culture in an animal model of uveal melanoma

    OpenAIRE

    Correa, Zelia Maria da Silva; Marshall,Jean-Claude; Souza Filho,João Pessoa de; Odashiro, Alexandre Nakao; Burnier, Jr.,Miguel Noel

    2009-01-01

    PURPOSE: To access the reliability of fine-needle aspiration biopsy in harvesting a sufficient amount of viable melanoma cells to establish a cell culture and maintain a melanoma cell line from an animal model of uveal melanoma. METHODS: For this study, fifteen male New Zealand albino rabbits had their right eye surgically inoculated with uveal melanoma cell line 92.1. The animals were immunosupressed with cyclosporine A using a dose schedule previously published. The animals were followed fo...

  20. Defining viability in mammalian cell cultures

    OpenAIRE

    Browne, Susan M.; Al-Rubeai, Mohamed

    2011-01-01

    Abstract A large number of assays are available to monitor viability in mammalian cell cultures with most defining loss of viability as a loss of plasma membrane integrity, a characteristic of necrotic cell death. However, the majority of cultured cells die by apoptosis and early apoptotic cells, although non-viable, maintain an intact plasma membrane and are thus ignored. Here we measure the viability of cultures of a number of common mammalian cell lines by assays that measure me...

  1. Dynamized Preparations in Cell Culture

    Directory of Open Access Journals (Sweden)

    Ellanzhiyil Surendran Sunila

    2009-01-01

    Full Text Available Although reports on the efficacy of homeopathic medicines in animal models are limited, there are even fewer reports on the in vitro action of these dynamized preparations. We have evaluated the cytotoxic activity of 30C and 200C potencies of ten dynamized medicines against Dalton's Lymphoma Ascites, Ehrlich's Ascites Carcinoma, lung fibroblast (L929 and Chinese Hamster Ovary (CHO cell lines and compared activity with their mother tinctures during short-term and long-term cell culture. The effect of dynamized medicines to induce apoptosis was also evaluated and we studied how dynamized medicines affected genes expressed during apoptosis. Mother tinctures as well as some dynamized medicines showed significant cytotoxicity to cells during short and long-term incubation. Potentiated alcohol control did not produce any cytotoxicity at concentrations studied. The dynamized medicines were found to inhibit CHO cell colony formation and thymidine uptake in L929 cells and those of Thuja, Hydrastis and Carcinosinum were found to induce apoptosis in DLA cells. Moreover, dynamized Carcinosinum was found to induce the expression of p53 while dynamized Thuja produced characteristic laddering pattern in agarose gel electrophoresis of DNA. These results indicate that dynamized medicines possess cytotoxic as well as apoptosis-inducing properties.

  2. Photothermally Activated Pyroelectric Polymer Films for Harvesting of Solar Heat with a Hybrid Energy Cell Structure.

    Science.gov (United States)

    Park, Teahoon; Na, Jongbeom; Kim, Byeonggwan; Kim, Younghoon; Shin, Haijin; Kim, Eunkyoung

    2015-12-22

    Photothermal effects in poly(3,4-ethylenedioxythiophene)s (PEDOTs) were explored for pyroelectric conversion. A poled ferroelectric film was coated on both sides with PEDOT via solution casting polymerization of EDOT, to give highly conductive and effective photothermal thin films of PEDOT. The PEDOT films not only provided heat source upon light exposure but worked as electrodes for the output energy from the pyroelectric layer in an energy harvester hybridized with a thermoelectric layer. Compared to a bare thermoelectric system under NIR irradiation, the photothermal-pyro-thermoelectric device showed more than 6 times higher thermoelectric output with the additional pyroelectric output. The photothermally driven pyroelectric harvesting film provided a very fast electric output with a high voltage output (Vout) of 15 V. The pyroelectric effect was significant due to the transparent and high photothermal PEDOT film, which could also work as an electrode. A hybrid energy harvester was assembled to enhance photoconversion efficiency (PCE) of a solar cell with a thermoelectric device operated by the photothermally generated heat. The PCE was increased more than 20% under sunlight irradiation (AM 1.5G) utilizing the transmitted light through the photovoltaic cell as a heat source that was converted into pyroelectric and thermoelectric output simultaneously from the high photothermal PEDOT electrodes. Overall, this work provides a dynamic and static hybrid energy cell to harvest solar energy in full spectral range and thermal energy, to allow solar powered switching of an electrochromic display.

  3. Hybrid energy harvester based on nanopillar solar cells and PVDF nanogenerator.

    Science.gov (United States)

    Lee, Dae-Yeong; Kim, Hyunjin; Li, Hua-Min; Jang, A-Rang; Lim, Yeong-Dae; Cha, Seung Nam; Park, Young Jun; Kang, Dae Joon; Yoo, Won Jong

    2013-05-03

    A tandem device which integrates a PVDF nanogenerator and silicon (Si) nanopillar solar cell is fabricated. The Si nanopillar solar cell was fabricated using a mask-free plasma etching technique and annealing process. The PVDF nanogenerator was stacked on top of the Si nanopillar solar cell using a spinning method. The optical properties and the device performance of nanowire solar cells have been characterized, and the dependence of device performance versus annealing time or method has been investigated. Furthermore, the PVDF nanogenerator was operated with a 100 dB sound wave and a 0.8 V peak to peak output voltage was generated. This tandem device can successfully harvest energy from both sound vibration and solar light, demonstrating its strong potential as a future ubiquitous energy harvester.

  4. Implementation of microbial fuel cell in harvesting energy using wastewater

    Science.gov (United States)

    Ramli, N. L.; Wahab, M. S. Abdul; Sharif, S. A. Md; Ramly, N. H.

    2016-02-01

    In this century, most of the companies use the electricity from the fossils fuels such as oil, gas and coal. This method will give negative impact to the environment and the fossils fuel will be run out. This project is to develop a microbial fuels cell that can produce electricity. There are several types of the microbial fuel cell, which are a single chamber, double chamber and continuous. In this paper, the double chamber microbial fuel cell was selected to investigate the effect of suspended sludge into the double chamber microbial fuels cell. The salt bridge will construct between both chambers of the double chamber microbial fuels cell. Carbon graphite rod is selected as an electrode at the cathode and anode to transfer the electron from the anode to the cathode. Electricity is generated from the anaerobic oxidation of organic matter by bacteria. At the end of this project, the microbial fuels cell was successful in generating electricity that can be used for a specific application.

  5. Dye-sensitized Solar Cells for Solar Energy Harvesting

    Science.gov (United States)

    Roy, M. S.; Deol, Y. S.; Kumar, Manish; Prasad, Narottam; Janu, Yojana

    2011-10-01

    Dye-sensitized solar cells (DSSCs) also known as Gratzel cells, have attracted the interests of researchers to a great extent because of its cost effective and easy manufacturing process without involving highly sophisticated lithographic technique and high cost raw materials as usually seen in conventional solar cell. Based on simple photo-electrochemical process, it has got immense potential in converting solar energy to electrical power in remote and desert area where the supply of conventional power is not possible. The overall peak power-production efficiency of dye-sensitized solar cells has been reported around 11 percent, so they are best suited to low-density applications and the price-to-performance ratio obtained through these solar cells is superior to others. DSSCs have ability to absorb even diffused sunlight and therefore work in cloudy whether as well without much impact over the efficiency. The present communication deals with a review of our work on DSSCs wherein we have used cost effective natural dyes/pigments as a sensitizer of nc-TiO2 and discussed about various key factors affecting the conversion efficiency of DSSC.

  6. Expanding intestinal stem cells in culture

    NARCIS (Netherlands)

    Heo, Inha; Clevers, Hans

    2015-01-01

    Culturing intestinal stem cells into 3D organoids results in heterogeneous cell populations, reflecting the in vivo cell type diversity. In a recent paper published in Nature, Wang et al. established a culture condition for a highly homogeneous population of intestinal stem cells.

  7. Expanding intestinal stem cells in culture

    NARCIS (Netherlands)

    Heo, Inha; Clevers, Hans

    Culturing intestinal stem cells into 3D organoids results in heterogeneous cell populations, reflecting the in vivo cell type diversity. In a recent paper published in Nature, Wang et al. established a culture condition for a highly homogeneous population of intestinal stem cells.

  8. Incomplete Exciton Harvesting from Fullerenes in Bulk Heterojunction Solar Cells

    KAUST Repository

    Burkhard, George F.

    2009-12-09

    We investigate the internal quantum efficiencies (IQEs) of high efficiency poly-3-hexylthiophene:[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) solar cells and find them to be lower at wavelengths where the PCBM absorbs. Because the exciton diffusion length in PCBM is too small, excitons generated in PCBM decay before reaching the donor-acceptor interface. This result has implications for most state of the art organic solar cells, since all of the most efficient devices use fullerenes as electron acceptors. © 2009 American Chemical Society.

  9. Cell culture media impact on drug product solution stability.

    Science.gov (United States)

    Purdie, Jennifer L; Kowle, Ronald L; Langland, Amie L; Patel, Chetan N; Ouyang, Anli; Olson, Donald J

    2016-07-08

    To enable subcutaneous administration of monoclonal antibodies, drug product solutions are often needed at high concentrations. A significant risk associated with high drug product concentrations is an increase in aggregate level over the shelf-life dating period. While much work has been done to understand the impact of drug product formulation on aggregation, there is limited understanding of the link between cell culture process conditions and soluble aggregate growth in drug product. During cell culture process development, soluble aggregates are often measured at harvest using cell-free material purified by Protein A chromatography. In the work reported here, cell culture media components were evaluated with respect to their impact on aggregate levels in high concentration solution drug product during accelerated stability studies. Two components, cysteine and ferric ammonium citrate, were found to impact aggregate growth rates in our current media (version 1) leading to the development of new chemically defined media and concentrated feed formulations. The new version of media and associated concentrated feeds (version 2) were evaluated across four cell lines producing recombinant IgG4 monoclonal antibodies and a bispecific antibody. In all four cell lines, the version 2 media reduced aggregate growth over the course of a 12 week accelerated stability study compared with the version 1 media, although the degree to which aggregate growth decreased was cell line dependent. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:998-1008, 2016.

  10. Energy harvesting by implantable abiotically catalyzed glucose fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kerzenmacher, S.; von Stetten, F. [Laboratory for MEMS Applications, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 106, D-79110 Freiburg (Germany); Ducree, J. [HSG-IMIT, Wilhelm-Schickard-Str. 10, D-78052 Villingen-Schwenningen (Germany); Zengerle, R. [Laboratory for MEMS Applications, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 106, D-79110 Freiburg (Germany); HSG-IMIT, Wilhelm-Schickard-Str. 10, D-78052 Villingen-Schwenningen (Germany)

    2008-07-15

    Implantable glucose fuel cells are a promising approach to realize an autonomous energy supply for medical implants that solely relies on the electrochemical reaction of oxygen and glucose. Key advantage over conventional batteries is the abundant availability of both reactants in body fluids, rendering the need for regular replacement or external recharging mechanisms obsolete. Implantable glucose fuel cells, based on abiotic catalysts such as noble metals and activated carbon, have already been developed as power supply for cardiac pacemakers in the late-1960s. Whereas, in vitro and preliminary in vivo studies demonstrated their long-term stability, the performance of these fuel cells is limited to the {mu}W-range. Consequently, no further developments have been reported since high-capacity lithium iodine batteries for cardiac pacemakers became available in the mid-1970s. In recent years research has been focused on enzymatically catalyzed glucose fuel cells. They offer higher power densities than their abiotically catalyzed counterparts, but the limited enzyme stability impedes long-term application. In this context, the trend towards increasingly energy-efficient low power MEMS (micro-electro-mechanical systems) implants has revived the interest in abiotic catalysts as a long-term stable alternative. This review covers the state-of-the-art in implantable abiotically catalyzed glucose fuel cells and their development since the 1960s. Different embodiment concepts are presented and the historical achievements of academic and industrial research groups are critically reviewed. Special regard is given to the applicability of the concept as sustainable micro-power generator for implantable devices. (author)

  11. Best practices in cell culture: an overview.

    Science.gov (United States)

    Baust, John M; Buehring, Gertrude Case; Campbell, Lia; Elmore, Eugene; Harbell, John W; Nims, Raymond W; Price, Paul; Reid, Yvonne A; Simione, Frank

    2017-08-14

    This overview describes a series of articles to provide an unmet need for information on best practices in animal cell culture. The target audience primarily consists of entry-level scientists with minimal experience in cell culture. It also include scientists, journalists, and educators with some experience in cell culture, but in need of a refresher in best practices. The articles will be published in this journal over a six-month period and will emphasize best practices in: (1) media selection; (2) use and evaluation of animal serum as a component of cell culture medium; (3) receipt of new cells into the laboratory; (4) naming cell lines; (5) authenticating cell line identity; (6) detecting and mitigating risk of cell culture contamination; (7) cryopreservation and thawing of cells; and (8) storing and shipping viable cells.

  12. Energy Harvesting Small Cell Networks: Feasibility, Deployment and Operation

    OpenAIRE

    Mao, Yuyi; Luo, Yaming; Zhang, Jun; Letaief, Khaled B.

    2015-01-01

    Small cell networks (SCNs) have attracted great attention in recent years due to their potential to meet the exponential growth of mobile data traffic and the increasing demand for better quality of service and user experience in mobile applications. Nevertheless, a wide deployment of SCNs has not happened yet because of the complexity in the network planning and optimization, as well as the high expenditure involved in deployment and operation. In particular, it is difficult to provide grid ...

  13. Endovascular biopsy: Technical feasibility of novel endothelial cell harvesting devices assessed in a rabbit aneurysm model.

    Science.gov (United States)

    Cooke, Daniel L; Bauer, Diana; Sun, Zhengda; Stillson, Carol; Nelson, Jeffrey; Barry, David; Hetts, Steven W; Higashida, Randall T; Dowd, Christopher F; Halbach, Van V; Su, Hua; Saeed, Maythem M

    2015-02-01

    The lack of safe and reliable methods to sample vascular tissue in situ limits discovery of the underlying genetic and pathophysiological mechanisms of many vascular disorders, including aneurysms. We investigated the feasibility and comparable efficacy of in vivo vascular endothelial cell sampling using a spectrum of endovascular devices. Using the rabbit elastase carotid aneurysm model we evaluated the performance of existing aneurysmal coils, intracranial stents, and stent-like devices to collect vascular endothelial cells. Additionally, we modified a subset of devices to assess the effects of alterations to coil pitch, coil wire contour, and stent surface finishing. Device performance was evaluated by (1) the number of viable endothelial cells harvested, (2) the degree of vascular wall damage analyzed using digital subtraction angiography and histopathological analysis, and (3) the ease of device navigability and retrieval. Isolated cells underwent immunohistochemical analysis to confirm cell type and viability. Coil and stent specifications, technique, and endothelial cell counts were tabulated and statistical analysis performed. Using conventional detachable-type and modified aneurysm coils 11 of 14 (78.6%) harvested endothelial cells with a mean of 7.93 (±8.33) cells/coil, while 15 of 15 (100%) conventional stents, stent-like devices and modified stents harvested endothelial cells with a mean of 831.33 (±887.73) cells/device. Coil stiffness was significantly associated with endothelial cell count in univariate analysis (p = 0.044). For stents and stent-like devices univariate analysis demonstrated stent-to-aorta diameter ratios (p = 0.001), stent length (p = 0.049), and the use of a pulling retrieval technique (p = 0.019) significantly predictive of endothelial cell counts, though a multivariate model using these variables demonstrated only the stent-to-aorta diameter ratio (p = 0.029) predictive of endothelial cell counts. Modified

  14. Endovascular biopsy: Technical feasibility of novel endothelial cell harvesting devices assessed in a rabbit aneurysm model

    Science.gov (United States)

    Bauer, Diana; Sun, Zhengda; Stillson, Carol; Nelson, Jeffrey; Barry, David; Hetts, Steven W; Higashida, Randall T; Dowd, Christopher F; Halbach, Van V; Su, Hua; Saeed, Maythem M

    2015-01-01

    The lack of safe and reliable methods to sample vascular tissue in situ limits discovery of the underlying genetic and pathophysiological mechanisms of many vascular disorders, including aneurysms. We investigated the feasibility and comparable efficacy of in vivo vascular endothelial cell sampling using a spectrum of endovascular devices. Using the rabbit elastase carotid aneurysm model we evaluated the performance of existing aneurysmal coils, intracranial stents, and stent-like devices to collect vascular endothelial cells. Additionally, we modified a subset of devices to assess the effects of alterations to coil pitch, coil wire contour, and stent surface finishing. Device performance was evaluated by (1) the number of viable endothelial cells harvested, (2) the degree of vascular wall damage analyzed using digital subtraction angiography and histopathological analysis, and (3) the ease of device navigability and retrieval. Isolated cells underwent immunohistochemical analysis to confirm cell type and viability. Coil and stent specifications, technique, and endothelial cell counts were tabulated and statistical analysis performed. Using conventional detachable-type and modified aneurysm coils 11 of 14 (78.6%) harvested endothelial cells with a mean of 7.93 (±8.33) cells/coil, while 15 of 15 (100%) conventional stents, stent-like devices and modified stents harvested endothelial cells with a mean of 831.33 (±887.73) cells/device. Coil stiffness was significantly associated with endothelial cell count in univariate analysis (p = 0.044). For stents and stent-like devices univariate analysis demonstrated stent-to-aorta diameter ratios (p = 0.001), stent length (p = 0.049), and the use of a pulling retrieval technique (p = 0.019) significantly predictive of endothelial cell counts, though a multivariate model using these variables demonstrated only the stent-to-aorta diameter ratio (p = 0.029) predictive of endothelial cell counts. Modified

  15. Cell density monitoring and control of microencapsulated CHO cell cultures

    OpenAIRE

    Cole, Harriet Emma

    2015-01-01

    Though mammalian cells play a key role in the manufacturing of recombinant glycosylated proteins, cell cultures and productivity are limited by the lack of suitable systems to enable stable perfusion culture. Microencapsulation, or entrapping cells within a semi-permeable membrane, offers the potential to generate high cell density cultures and improve the productivity by mimicking the cells natural environment. However, the cells being secluded by the microcapsules membrane are difficult to ...

  16. Active energy harvesting from microbial fuel cells at the maximum power point without using resistors.

    Science.gov (United States)

    Wang, Heming; Park, Jae-Do; Ren, Zhiyong

    2012-05-01

    Microbial fuel cell (MFC) technology offers a sustainable approach to harvest electricity from biodegradable materials. Energy production from MFCs has been demonstrated using external resistors or charge pumps, but such methods can only dissipate energy through heat or receive electrons passively from the MFC without any controllability. This study developed a new approach and system that can actively extract energy from MFC reactors at any operating point without using any resistors, especially at the peak power point to maximize energy production. Results show that power harvesting from a recirculating-flow MFC can be well maintained by the maximum power point circuit (MPPC) at its peak power point, while a charge pump was not able to change operating point due to current limitation. Within 18-h test, the energy gained from the MPPC was 76.8 J, 76 times higher than the charge pump (1.0 J) that was commonly used in MFC studies. Both conditions resulted in similar organic removal, but the Coulombic efficiency obtained from the MPPC was 21 times higher than that of the charge pump. Different numbers of capacitors could be used in the MPPC for various energy storage requirements and power supply, and the energy conversion efficiency of the MPPC was further characterized to identify key factors for system improvement. This active energy harvesting approach provides a new perspective for energy harvesting that can maximize MFC energy generation and system controllability.

  17. Cell culture techniques in honey bee research

    Science.gov (United States)

    Cell culture techniques are indispensable in most if not all life science disciplines to date. Wherever cell culture models are lacking scientific development is hampered. Unfortunately this has been and still is the case in honey bee research because permanent honey bee cell lines have not yet been...

  18. Cell Culture as an Alternative in Education.

    Science.gov (United States)

    Nardone, Roland M.

    1990-01-01

    Programs that are intended to inform and provide "hands-on" experience for students and to facilitate the introduction of cell culture-based laboratory exercises into the high school and college laboratory are examined. The components of the CellServ Program and the Cell Culture Toxicology Training Programs are described. (KR)

  19. Realizing Efficient Energy Harvesting from Organic Photovoltaic Cells

    Science.gov (United States)

    Zou, Yunlong

    Organic photovoltaic cells (OPVs) are emerging field of research in renewable energy. The development of OPVs in recent years has made this technology viable for many niche applications. In order to realize widespread application however, the power conversion efficiency requires further improvement. The efficiency of an OPV depends on the short-circuit current density (JSC), open-circuit voltage (VOC) and fill factor (FF). For state-of-the-art devices, JSC is mostly optimized with the application of novel low-bandgap materials and a bulk heterojunction device architecture (internal quantum efficiency approaching 100%). The remaining limiting factors are the low VOC and FF. This work focuses on overcoming these bottlenecks for improved efficiency. Temperature dependent measurements of device performance are used to examine both charge transfer and exciton ionization process in OPVs. The results permit an improved understanding of the intrinsic limit for VOC in various device architectures and provide insight on device operation. Efforts have also been directed at engineering device architecture for optimized FF, realizing a very high efficiency of 8% for vapor deposited small molecule OPVs. With collaborators, new molecules with tailored desired energy levels are being designed for further improvements in efficiency. A new type of hybrid organic-inorganic perovskite material is also included in this study. By addressing processing issues and anomalous hysteresis effects, a very high efficiency of 19.1% is achieved. Moving forward, topics including engineering film crystallinity, exploring tandem architectures and understanding degradation mechanisms will further push OPVs toward broad commercialization.

  20. Cell wall chemical characteristics of whole‐crop cereal silages harvested at three maturity stages

    OpenAIRE

    Wallsten, Johanna; Hatfield, Ronald

    2016-01-01

    Abstract Background In cooler climates such as found in Scandinavian countries cereals are important feedstuffs for ruminants often ensiled as whole‐crop cereal silages (WCCS) to preserve nutrients. Animal performance varies with the type of cereal forage and stage of cereal development being ensiled. Cell wall isolation and analysis was undertaken to determine differences among cereal silages harvested at different stages of maturity. Results A set of 27 WCCS samples of barley, wheat and oat...

  1. Primary Culture of Porcine Pancreatic Acinar Cells

    OpenAIRE

    2001-01-01

    OBJECTIVE: To develop a method for the primary culture of porcine pancreatic acinar cells. INTERVENTIONS: Dispersed pancreatic acinar cells available utilizing RPMI-1640 medium containing collagenase III. After purification, the isolated acinar cells were cultured in RPMI-1640 medium with the addition of 2.5% fetal bovine serum. MAIN OUTCOME MEASURES: The morphological characteristics of acinar cells were described. (3)H-thymidine incorporation of acinar cells and the activity of amylase or l...

  2. Three-Dimensional Scaffold from Decellularized Human Gingiva for Cell Cultures: Glycoconjugates and Cell Behavior

    Directory of Open Access Journals (Sweden)

    Seyed Ali Banihashem Rad

    2013-01-01

    Full Text Available Objective: We studied both the presence of some carbohydrate compounds in a three-dimensional (3D matrix harvested from human gingiva and the cell behavior in this matrix.Materials and Methods: In this experimental research, in order to prepare 3D scaffolds, human palatal gingival biopsies were harvested and physically decellularized by freeze-thawing and sodium dodecyl sulfate (SDS. The scaffolds were placed within the rings of blastema tissues obtained from a pinna rabbit, in vitro. We evaluated the presence of glycoconjugatesand cellular behavior according to histological, histochemical and spectrophotometry techniques at one, two and three weeks after culture. One-way analysis of variance (ANOVAcomparedthe groups.Results: Extracellular matrix (ECM remained after decellularization of tissue with 1% SDS. Glycoconjugate contents decreased meaningfully at a higher SDS concentration (p<0.0001. After culture of the ECM scaffold with blastema, we observed increased staining of alcian blue, periodic acid-Schiff (PAS and toluidine blue in the scaffold and a number of other migrant cells which was caused by cell penetrationinto the scaffold. Spectrophotometry results showed an increase in glycosaminoglycans (GAGs of the decellularized scaffolds at three weeks after culture.Conclusion: The present study has shown that a scaffold generated from palatal gingival tissue ECM is a suitable substrate for blastema cell migration and activity.This scaffold maypotentially be useful as a biological scaffold in tissue engineering applications.

  3. Performance degradation of high-power lithium-ion cells-Electrochemistry of harvested electrodes

    Science.gov (United States)

    Abraham, D. P.; Knuth, J. L.; Dees, D. W.; Bloom, I.; Christophersen, J. P.

    The performance of 18650-type high-power lithium-ion cells is being evaluated as part of the U.S. Department of Energy's (DOEs) Advanced Technology Development (ATD) program. In this article, we present accelerated aging data acquired on 18650-cells containing LiNi 0.8Co 0.15Al 0.05O 2- or LiNi 0.8Co 0.1Al 0.1O 2-based positive electrodes, MAG-10 graphite-based negative electrodes, and 1.2-M LiPF 6 in EC:EMC (3:7 by wt.) electrolyte. Capacity and impedance data acquired on electrodes harvested from these cells highlight the contributions of the positive and negative electrodes to the degradation of cell performance. We also describe test methodologies used to examine the electrochemical characteristics of the harvested electrodes. Identifying and optimizing cell components responsible for performance degradation should enable the development of new lithium-ion cell chemistries that will meet the 15-year cell calendar life goal established by DOEs FreedomCar initiative.

  4. Performance degradation of high-power lithium-ion cells - Electrochemistry of harvested electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, D.P.; Knuth, J.L.; Dees, D.W.; Bloom, I. [Argonne National Laboratory, Argonne, IL 60439 (United States); Christophersen, J.P. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States)

    2007-07-10

    The performance of 18650-type high-power lithium-ion cells is being evaluated as part of the U.S. Department of Energy's (DOEs) Advanced Technology Development (ATD) program. In this article, we present accelerated aging data acquired on 18650-cells containing LiNi{sub 0.8}Co{sub 0.15}Al{sub 0.05}O{sub 2}- or LiNi{sub 0.8}Co{sub 0.1}Al{sub 0.1}O{sub 2}-based positive electrodes, MAG-10 graphite-based negative electrodes, and 1.2-M LiPF{sub 6} in EC:EMC (3:7 by wt.) electrolyte. Capacity and impedance data acquired on electrodes harvested from these cells highlight the contributions of the positive and negative electrodes to the degradation of cell performance. We also describe test methodologies used to examine the electrochemical characteristics of the harvested electrodes. Identifying and optimizing cell components responsible for performance degradation should enable the development of new lithium-ion cell chemistries that will meet the 15-year cell calendar life goal established by DOEs FreedomCar initiative. (author)

  5. Culture of Cells from Amphibian Embryos.

    Science.gov (United States)

    Stanisstreet, Martin

    1983-01-01

    Describes a method for in vitro culturing of cells from amphibian early embryos. Such cells can be used to demonstrate such properties of eukaryote cells as cell motility, adhesion, differentiation, and cell sorting into tissues. The technique may be extended to investigate other factors. (Author/JN)

  6. Neural cell co-culture induced differentiation of bone marrow mesenchymal stem cells into neuronal-like cells

    Institute of Scientific and Technical Information of China (English)

    Nailong Yang; Lili Xu; Fen Yang

    2008-01-01

    BACKGROUND: It has been previously demonstrated that the neural cell microenvironment has the ability to induce differentiation of bone marrow mesenchymal stem cells (BMSCs) into the neural cells.OBJECTIVE: To establish a co-culture system of human BMSCs and neural cells, and to observe effects of this co-culture system on differentiation of human BMSCs into neural cells.DESIGN, TIME AND SETTING: A comparative observation experiment, performed at the Center Laboratory of the Affiliated Hospital of Medical College Qingdao University from October 2006 to December 2007.MATERIALS: Neural cells were obtained from human fetal brain tissue. BMSCs were harvested from female patients that underwent autonomous stem cell transplantation.METHODS: BMSCs in the co-culture group consisted of BMSCs and third passage neural cells. BMSCs in the control group were solely cultured in vitro.MAIN OUTCOME MEASURES: Morphological changes of BMSCs were observed, and expression of the neuronal specific marker, neuron-specific enolase (NSE), was analyzed by immunofluorescence staining after4-5-day co-culture.RESULTS: The number of neural cells in the co-culture group increased and the cells spread on the culture bottle surface. Radial dendrite formed and connected with each other. NSE-immunoreactive cells were also detected. The positive ratio of NSE-positive cells reached (32.7±11.5)%, with morphological characteristics similar to neuronal cells. Human BMSCs did not express NSE in the control group.CONCLUSION: The microenvironment provided by neurons induced differentiation of BMSCs into neuronal-like cells.

  7. Primary Culture of Porcine Pancreatic Acinar Cells

    Directory of Open Access Journals (Sweden)

    Zhao X

    2001-03-01

    Full Text Available OBJECTIVE: To develop a method for the primary culture of porcine pancreatic acinar cells. INTERVENTIONS: Dispersed pancreatic acinar cells available utilizing RPMI-1640 medium containing collagenase III. After purification, the isolated acinar cells were cultured in RPMI-1640 medium with the addition of 2.5% fetal bovine serum. MAIN OUTCOME MEASURES: The morphological characteristics of acinar cells were described. (3H-thymidine incorporation of acinar cells and the activity of amylase or lipase were determined during the culture process. RESULTS: There were no remarkable morphological changes in the pancreatic acinar cells during the 20 days culture. The acini showed a tendency to gather but did not attach to the walls of the culture disks. A good (3H-thymidine incorporation of acinar cells in the primary culture was maintained. The secretion of amylase or lipase from the acini decreased with the length of time of the culture. DISCUSSION: The primary culture of acinar cells from a porcine pancreas which was carried out in this study maintained the normal morphology of the acinar cells and their ability to grow but not their secretion of amylase or lipase. The method would benefit by the further experiments on acini of porcine pancreas.

  8. Tooth tissue engineering: optimal dental stem cell harvest based on tooth development.

    Science.gov (United States)

    Duailibi, Monica Talarico; Duailibi, Silvio Eduardo; Duailibi Neto, Eduardo Felippe; Negreiros, Renata Matalon; Jorge, Waldyr Antonio; Ferreira, Lydia Masako; Vacanti, Joseph Phillip; Yelick, Pamela Crotty

    2011-07-01

    Our long-term objective is to devise reliable methods to generate biological replacement teeth exhibiting the physical properties and functions of naturally formed human teeth. Previously, we demonstrated the successful use of tissue engineering approaches to generate small, bioengineered tooth crowns from harvested pig and rat postnatal dental stem cells (DSCs). To facilitate characterizations of human DSCs, we have developed a novel radiographic staging system to accurately correlate human third molar tooth developmental stage with anticipated harvested DSC yield. Our results demonstrated that DSC yields were higher in less developed teeth (Stages 1 and 2), and lower in more developed teeth (Stages 3, 4, and 5). The greatest cell yields and colony-forming units (CFUs) capability was obtained from Stages 1 and 2 tooth dental pulp. We conclude that radiographic developmental staging can be used to accurately assess the utility of harvested human teeth for future dental tissue engineering applications. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  9. Culture and purification of human fetal olfactory bulb ensheathing cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective: To obtain high purity of human fetal olfactory bulb ensheathing cells (OB-hOECs) in vitro and to develop a simple and effective method for primary culture of OB-hOECs. Methods: OB-hOECs were cultured based on the differential rates of attachment of the various harvested cell types. Then the method was combined with arabinoside cytosine (Ara-C)inhibition, serum-free starvation or intermittent neurotrophin 3 (NT3) nutrition method to observe cell states in different cultural environments. The purity of OB-hOECs was assessed with immunocytochemical analysis. Results: OB-hOECs appeared bipolar and tripolar shape, with slender processes forming network. The purity of OECs reached 88% with the selective attachment method on day 6, and then fibroblast proliferated quickly and reduced the purity. When combined with the starvation method, the purity of OECs was 91% on day 6 and 86% on day 9, however, OECs were in a poor state. While combined with the NT3 method, the purity reached 95% on day 9 and 83% on day 12, respectively. The cells still remained in a good state. Conclusion: A combination of selective attachment and intermittent NT3 nutrition is an effective method to obtain OECs with higher purity and quality.

  10. Method and Apparatus for a Miniature Bioreactor System for Long-Term Cell Culture

    Science.gov (United States)

    Kleis, Stanley J. (Inventor); Geffert, Sandra K. (Inventor); Gonda, Steve R. (Inventor)

    2015-01-01

    A bioreactor and method that permits continuous and simultaneous short, moderate, or long term cell culturing of one or more cell types or tissue in a laminar flow configuration is disclosed, where the bioreactor supports at least two laminar flow zones, which are isolated by laminar flow without the need for physical barriers between the zones. The bioreactors of this invention are ideally suited for studying short, moderate and long term studies of cell cultures and the response of cell cultures to one or more stressors such as pharmaceuticals, hypoxia, pathogens, or any other stressor. The bioreactors of this invention are also ideally suited for short, moderate or long term cell culturing with periodic cell harvesting and/or medium processing for secreted cellular components.

  11. Efficiency Enhancement of InGaN-Based Solar Cells via Stacking Layers of Light-Harvesting Nanospheres

    OpenAIRE

    Amal M. Al-Amri; Po-Han Fu; Kun-Yu Lai; Hsin-Ping Wang; Lain-Jong Li; Jr-Hau He

    2016-01-01

    An effective light-harvesting scheme for InGaN-based multiple quantum well solar cells is demonstrated using stacking layers of polystyrene nanospheres. Light-harvesting efficiencies on the solar cells covered with varied stacks of nanospheres are evaluated through numerical and experimental methods. The numerical simulation reveals that nanospheres with 3 stacking layers exhibit the most improved optical absorption and haze ratio as compared to those obtained by monolayer nanospheres. The ex...

  12. Triboelectric-pyroelectric-piezoelectric hybrid cell for high-efficiency energy-harvesting and self-powered sensing.

    Science.gov (United States)

    Zi, Yunlong; Lin, Long; Wang, Jie; Wang, Sihong; Chen, Jun; Fan, Xing; Yang, Po-Kang; Yi, Fang; Wang, Zhong Lin

    2015-04-08

    A triboelectric-pyroelectric-piezoelectric hybrid cell, consisting of a triboelectric nanogenerator and a pyroelectric-piezoelectric nanogenerator, is developed for highly efficient mechanical energy harvesting through multiple mechanisms. The excellent performance of the hybrid cell enhances the energy-harvesting efficiency significantly (by 26.2% at 1 kΩ load resistance), and enables self-powered sensing, which will lead to a variety of advanced applications.

  13. Energy Harvesting by Subcutaneous Solar Cells: A Long-Term Study on Achievable Energy Output.

    Science.gov (United States)

    Bereuter, L; Williner, S; Pianezzi, F; Bissig, B; Buecheler, S; Burger, J; Vogel, R; Zurbuchen, A; Haeberlin, A

    2017-01-03

    Active electronic implants are powered by primary batteries, which induces the necessity of implant replacement after battery depletion. This causes repeated interventions in a patients' life, which bears the risk of complications and is costly. By using energy harvesting devices to power the implant, device replacements may be avoided and the device size may be reduced dramatically. Recently, several groups presented prototypes of implants powered by subcutaneous solar cells. However, data about the expected real-life power output of subcutaneously implanted solar cells was lacking so far. In this study, we report the first real-life validation data of energy harvesting by subcutaneous solar cells. Portable light measurement devices that feature solar cells (cell area = 3.6 cm(2)) and continuously measure a subcutaneous solar cell's output power were built. The measurement devices were worn by volunteers in their daily routine in summer, autumn and winter. In addition to the measured output power, influences such as season, weather and human activity were analyzed. The obtained mean power over the whole study period was 67 µW (=19 µW cm(-2)), which is sufficient to power e.g. a cardiac pacemaker.

  14. Recent trends in mesoscopic solar cells based on molecular and nanopigment light harvesters

    Directory of Open Access Journals (Sweden)

    Carole Grätzel

    2013-01-01

    Full Text Available Mesoscopic solar cells are one of the most promising photovoltaic technologies among third generation photovoltaics due to their low cost and high efficiency. The morphology of wide-band semiconductors, sensitized with molecular or nanosized light harvesters, used as electron collectors contribute substantially to the device performance. Recent developments in the use of organic–inorganic layer structured perovskites as light absorbers and as electron or hole transport materials allows reduction in the thickness of photoanodes to the submicron level and have raised the power conversion efficiency of solid state mesoscopic solar cells above the 10% level.

  15. Recent trends in mesoscopic solar cells based on molecular and nanopigment light harvesters

    KAUST Repository

    Grätzel, Carole

    2013-01-01

    Mesoscopic solar cells are one of the most promising photovoltaic technologies among third generation photovoltaics due to their low cost and high efficiency. The morphology of wide-band semiconductors, sensitized with molecular or nanosized light harvesters, used as electron collectors contribute substantially to the device performance. Recent developments in the use of organic-inorganic layer structured perovskites as light absorbers and as electron or hole transport materials allows reduction in the thickness of photoanodes to the submicron level and have raised the power conversion efficiency of solid state mesoscopic solar cells above the 10% level.

  16. Embryonic Stem Cells: Isolation, Characterization and Culture

    Science.gov (United States)

    Amit, Michal; Itskovitz-Eldor, Joseph

    Embryonic stem cells are pluripotent cells isolated from the mammalian blastocyst. Traditionally, these cells have been derived and cultured with mouse embryonic fibroblast (MEF) supportive layers, which allow their continuous growth in an undifferentiated state. However, for any future industrial or clinical application hESCs should be cultured in reproducible, defined, and xeno-free culture system, where exposure to animal pathogens is prevented. From their derivation in 1998 the methods for culturing hESCs were significantly improved. This chapter wills discuss hESC characterization and the basic methods for their derivation and maintenance.

  17. Cell Suspension Culture of Neem Tree

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The establishment of suspension culture system for neem (Azadirachta indica A. Juss) cells and the suspension culture condition was studied. It shows that the neem cell suspension culture system was best in B5 liquid medium, 2.0~4.0mg/L NAA with direct spill method. Based on the integrated analysis of cell biomass, Azadirachtin content and productivity, the optimum culture conditions were B5 liquid medium, 2.0-4.0 mg/L NAA, 3% sucrose at 25 ℃. The optimum rotating speed of the shaker and broth content d...

  18. Bio-Photoelectrochemical Solar Cells Incorporating Reaction Center and Reaction Center Plus Light Harvesting Complexes

    Science.gov (United States)

    Yaghoubi, Houman

    Harvesting solar energy can potentially be a promising solution to the energy crisis now and in the future. However, material and processing costs continue to be the most important limitations for the commercial devices. A key solution to these problems might lie within the development of bio-hybrid solar cells that seeks to mimic photosynthesis to harvest solar energy and to take advantage of the low material costs, negative carbon footprint, and material abundance. The bio-photoelectrochemical cell technologies exploit biomimetic means of energy conversion by utilizing plant-derived photosystems which can be inexpensive and ultimately the most sustainable alternative. Plants and photosynthetic bacteria harvest light, through special proteins called reaction centers (RCs), with high efficiency and convert it into electrochemical energy. In theory, photosynthetic RCs can be used in a device to harvest solar energy and generate 1.1 V open circuit voltage and ~1 mA cm-2 short circuit photocurrent. Considering the nearly perfect quantum yield of photo-induced charge separation, efficiency of a protein-based solar cell might exceed 20%. In practice, the efficiency of fabricated devices has been limited mainly due to the challenges in the electron transfer between the protein complex and the device electrodes as well as limited light absorption. The overarching goal of this work is to increase the power conversion efficiency in protein-based solar cells by addressing those issues (i.e. electron transfer and light absorption). This work presents several approaches to increase the charge transfer rate between the photosynthetic RC and underlying electrode as well as increasing the light absorption to eventually enhance the external quantum efficiency (EQE) of bio-hybrid solar cells. The first approach is to decrease the electron transfer distance between one of the redox active sites in the RC and the underlying electrode by direct attachment of the of protein complex

  19. [Effects of beryllium chloride on cultured cells].

    Science.gov (United States)

    Sakaguchi, T; Sakaguchi, S; Nakamura, I; Kagami, M

    1984-05-01

    The effects of beryllium on cultured cells were investigated. Three cell-lines (HeLa-S3, Vero, HEL-R66) were used in these experiments and they were cultured in Eagle's MEM plus 5 or 10% FBS (Fetal Bovine Serum) containing beryllium in various concentrations. HeLa cells or Vero cells were able to grow in the medium with 10 micrograms Be/ml (1.1 mM). On the other hand, the growth of HEL cells were strongly inhibited, even when cultured in the medium with 1 microgram Be/ml (1.1 X 10(-1) mM) and the number of living cells showed markedly low level as compared to that of the control samples cultured in the medium without beryllium. The cytotoxic effects of beryllium on these cells, which were cultured for three days in the medium with beryllium, were observed. None of cytotoxic effects were found on HeLa cells cultured with 0.5 micrograms/ml (5.5 X 10(-2) mM) and on Vero cells cultured with 0.05 micrograms Be/ml (5.5 X 10(-3) mM), while HEL cells received cytotoxic effects even when cultured in the medium containing 0.05 micrograms Be/ml (5.5 X 10(-3) mM), and these effects on the cells appeared strong when cultured in the medium without FBS. It was revealed from these experiments that HEL cells are very sensitive in terms of toxic effects of beryllium. Therefore, there cells can be used for the toxicological study on low level concentrations of the metal.

  20. Rheological characteristics of cell suspension and cell culture of Perilla frutescens.

    Science.gov (United States)

    Zhong, J J; Seki, T; Kinoshita, S; Yoshida, T

    1992-12-01

    Physical properties such as viscosity, fluid dynamic behavior of cell suspension, and size distribution of cell aggregates of a plant, Perilla frustescens, cultured in a liquid medium were studied. As a result of investigations using cells harvester after 12 days of cultivation in a flask, it was found that the apparent viscosity of the cell suspension did not change with any variation of cell concentration below 5 g dry cell/L but markedly increased when the cell concentration increased over 12.8 g dry cell/L. The cell suspension exhibited the characteristics of a Bingham plastic fluid with a small yield stress. The size of cell aggregates in the range 74 to 500 mum did not influence the rheological characteristics of the cell suspension. The rheological characteristics of cultivation mixtures of P. frutescens cultivated in a flask and in a bioreactor were also investigated. The results showed that the flow characteristics of the cell culture could be described by a Bingham plastic model. At the later stage of cultivation, the apparent viscosity increased steadily, even though the biomass concentration (by dry weight) decreased, due to the increase of individual cell size.

  1. Dynamic culture improves cell reprogramming efficiency.

    Science.gov (United States)

    Sia, Junren; Sun, Raymond; Chu, Julia; Li, Song

    2016-06-01

    Cell reprogramming to pluripotency is an inefficient process and various approaches have been devised to improve the yield of induced pluripotent stem cells. However, the effect of biophysical factors on cell reprogramming is not well understood. Here we showed that, for the first time, dynamic culture with orbital shaking significantly improved the reprogramming efficiency in adherent cells. Manipulating the viscosity of the culture medium suggested that the improved efficiency is mainly attributed to convective mixing rather than hydrodynamic shear stress. Temporal studies demonstrated that the enhancement of reprogramming efficiency required the dynamic culture in the middle but not early phase. In the early phase, fibroblasts had a high proliferation rate, but as the culture became over-confluent in the middle phase, expression of p57 was upregulated to inhibit cell proliferation and consequently, cell reprogramming. Subjecting the over confluent culture to orbital shaking prevented the upregulation of p57, thus improving reprogramming efficiency. Seeding cells at low densities to avoid over-confluency resulted in a lower efficiency, and optimal reprogramming efficiency was attained at a high seeding density with dynamic culture. Our findings provide insight into the underlying mechanisms of how dynamic culture condition regulate cell reprogramming, and will have broad impact on cell engineering for regenerative medicine and disease modeling.

  2. New culture medium concepts for cell transplantation.

    Science.gov (United States)

    Lee, S; Kim, B Y; Yeo, J E; Nemeno, J G; Jo, Y H; Yang, W; Nam, B M; Namoto, S; Tanaka, S; Sato, M; Lee, K M; Hwang, H S; Lee, J I

    2013-10-01

    Before cell or tissue transplantation, cells or tissues have to be maintained for a certain period in vitro using culture medium and methods. Most culture media contain substances such as pH indicators and buffers. It is not known whether some of these substances are safe for subsequent application in the transplantation of cells or tissues into the human body. We investigated culture media and methods with respect to the safety of the components in future transplantation applications. A modified culture medium--medical fluid-based culture medium (FCM)--was designed by using various fluids and injectable drugs that are already currently permitted for use in clinical medicine. Medium components necessary for optimal cell growth were obtained from approved drugs. FCM was manufactured with adjusted final concentrations of the medium components similar to those in commercial Dulbecco's modified Eagle's medium (DMEM). In particular, 1029.40 mg/L amino acids, approximately 88.85 mg/L vitamins, 13,525.77 mg/L inorganic salts, and 4500 mg/L D-glucose comprise the high-glucose FCM. Next, human fat synovium-derived mesenchymal stem cells and rat H9c2 (2-1) cells were cultured under 2 conditions: (1) DMEM-high glucose (HG), an original commercial medium, and (2) optimized FCM-HG. We assessed the morphologies and proliferation rates of these cells. We observed that FCM-HG was able to induce the growth of FS-MSC and commercially available H9c2 cell. The morphologies and proliferation patterns of these cells cultured under FCM-HG showed no differences compared with cells grown in DMEM-HG. Our data suggest that FCM, which we developed for the first time according to the concept of drug repositioning, was a useful culture medium, especially in cultured cells intended for human cell transplantation. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  3. Nutrients and pharmaceuticals removal from wastewater by culture and harvesting of Chlorella sorokiniana.

    Science.gov (United States)

    Escapa, C; Coimbra, R N; Paniagua, S; García, A I; Otero, M

    2015-06-01

    This work aimed to study both the removal of nutrients and pharmaceuticals, namely salicylic acid or paracetamol, from water by the culture of Chlorella sorokiniana. The removal of nutrients was nearly complete at the end of the batch culture; above 70% for nitrates and 89% for phosphates in the semicontinuous culture. The pharmaceuticals removal kinetics were 2.3 times greater for the salicylic acid than paracetamol, reaching volumetric efficiencies above 93% for salicylic acid in the semicontinuous culture. Finally, to separate the microalgae biomass from treated water, metal salts, synthetic polyelectrolytes and a biopolymer were tested as coagulants-flocculants. The best flocculation results were achieved with AlCl3 (95.23% with 200mgg(-1), 1min incubation time). However, given that resulting flocs had different characteristics, flocculants must be chosen on the basis of the subsequent use of the biomass.

  4. Autofluorescence of viable cultured mammalian cells.

    Science.gov (United States)

    Aubin, J E

    1979-01-01

    The autofluorescence other than intrinsic protein emission of viable cultured mammalian cells has been investigated. The fluorescence was found to originate in discrete cytoplasmic vesicle-like regions and to be absent from the nucleus. Excitation and emission spectra of viable cells revealed at least two distinct fluorescent species. Comparison of cell spectra with spectra of known cellular metabolites suggested that most, if not all, of the fluorescence arises from intracellular nicotinamide adenine dinucleotide (NADH) and riboflavin and flavin coenzymes. Various changes in culture conditions did not affect the observed autofluorescence intensity. A multiparameter flow system (MACCS) was used to compare the fluorescence intensities of numerous cultured mammalian cells.

  5. An Improved Harvest and in Vitro Expansion Protocol for Murine Bone Marrow-Derived Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Song Xu

    2010-01-01

    Full Text Available Compared to bone marrow (BM derived mesenchymal stem cells (MSCs from human origin or from other species, the in vitro expansion and purification of murine MSCs (mMSCs is much more difficult because of the low MSC yield and the unwanted growth of non-MSCs in the in vitro expansion cultures. We describe a modified protocol to isolate and expand murine BM derived MSCs based on the combination of mechanical crushing and collagenase digestion at the moment of harvest, followed by an immunodepletion step using microbeads coated with CD11b, CD45 and CD34 antibodies. The number of isolated mMSCs as estimated by colony forming unit-fibroblast (CFU-F assay showed that this modified isolation method could yield 70.0% more primary colonies. After immunodepletion, a homogenous mMSC population could already be obtained after two passages. Immunodepleted mMSCs (ID-mMSCs are uniformly positive for stem cell antigen-1 (Sca-1, CD90, CD105 and CD73 cell surface markers, but negative for the hematopoietic surface markers CD14, CD34 and CD45. Moreover the immunodepleted cell population exhibits more differentiation potential into adipogenic, osteogenic and chondrogenic lineages. Our data illustrate the development of an efficient and reliable expansion protocol increasing the yield and purity of mMSCs and reducing the overall expansion time.

  6. In vitro culture of hybridoma cells in agarose beads producing antibody secretion for two weeks.

    Science.gov (United States)

    Cadic, C; Dupuy, B; Pianet, I; Merle, M; Margerin, C; Bezian, J H

    1992-01-05

    A new process for embedding cells in agarose is described. Beads were obtained by extruding an ultralow gelling temperature agarose solution in a capillary containing a hydrophobic medium flowthrough. The toxicity of the procedure has been evaluated by monitoring the energy status of agarose-embedded C(6) glioma cells with (31)P nuclear magnetic resonance (NMR). Suspension and microbead cultures of hybridoma cell line were compared. In suspension culture the number of cells and the antibody concentrations increased for 5 days before the stationary phase began, when the cultures were stopped. In agarose bead cultures, the gel provided an enormous support surface area (50 m(2)/ mL of gel). It was possible to seed 20-fold more cells. The gel pressure modified the proliferative process and antibody pattern secretion. In particular, the antibodies could be harvested for two weeks.

  7. Emulsions Containing Perfluorocarbon Support Cell Cultures

    Science.gov (United States)

    Ju, Lu-Kwang; Lee, Jaw Fang; Armiger, William B.

    1990-01-01

    Addition of emulsion containing perfluorocarbon liquid to aqueous cell-culture medium increases capacity of medium to support mammalian cells. FC-40 Fluorinert (or equivalent) - increases average density of medium so approximately equal to that of cells. Cells stay suspended in medium without mechanical stirring, which damages them. Increases density enough to prevent cells from setting, and increases viscosity of medium so oxygen bubbled through it and nutrients stirred in with less damage to delicate cells.

  8. Endovascular Biopsy: Evaluating the Feasibility of Harvesting Endothelial Cells Using Detachable Coils

    Science.gov (United States)

    Cooke, Daniel L.; Su, Hua; Sun, Zhengda; Guo, Yi; Guo, Diana; Saeed, Maythem M.; Hetts, Steven W.; Higashida, Randall T.; Dowd, Christopher F.; Young, William L.; Halbach, Van V.

    2013-01-01

    Summary The absence of safe and reliable methods to harvest vascular tissue in situ limits the discovery of the underlying genetic and pathophysiological mechanisms of many vascular disorders such as aneurysms. We investigated the feasibility and comparable efficacy of endothelial cell collection using a spectrum of endovascular coils. Nine detachable coils ranging in k coefficient (0.15-0.24), diameter (4.0 mm-16.0 mm), and length (8.0 cm-47.0 cm) were tested in pigs. All coils were deployed and retrieved within the iliac artery of pigs (three coils/pig). Collected coils were evaluated under light microscopy. The total and endothelial cells collected by each coil were quantified. The nucleated cells were identified by Wright-Giemsa and DAPI stains. Endothelial and smooth muscle cells were identified by CD31 and α-smooth muscle actin antibody staining. Coils were deployed and retrieved without technical difficulty. Light microscopy demonstrated sheets of cellular material concentrated within the coil winds. All coils collected cellular material while five of nine (55.6%) coils retrieved endothelial cells. Coils collected mean endothelial cell counts of 89.0±101.6. Regression analysis demonstrated a positive correlation between increasing coil diameter and endothelial cell counts (R2=0.52, p = 0.029). Conventional detachable coils can be used to harvest endothelial cells. The number of endothelial cells collected by a coil positively correlated with its diameter. Given the widespread use of coils and their well-described safety profile their potential as an endovascular biopsy device would expand the availability of tissue for cellular and molecular analysis. PMID:24355142

  9. Platinum Alloy Tailored All-Weather Solar Cells for Energy Harvesting from Sun and Rain.

    Science.gov (United States)

    Tang, Qunwei; Duan, Yanyan; He, Benlin; Chen, Haiyan

    2016-11-07

    Solar cells that can harvest energy in all weathers are promising in solving the energy crisis and environmental problems. The power outputs are nearly zero under dark conditions for state-of-the-art solar cells. To address this issue, we present herein a class of platinum alloy (PtMx , M=Ni, Fe, Co, Cu, Mo) tailored all-weather solar cells that can harvest energy from rain and realize photoelectric conversion under sun illumination. By tuning the stoichiometric Pt/M ratio and M species, the optimized solar cell yields a photoelectric conversion efficiency of 10.38 % under simulated sunlight irradiation (AM 1.5, 100 mW cm(-2) ) as well as current of 3.90 μA and voltage of 115.52 μV under simulated raindrops. Moreover, the electric signals are highly dependent on the dripping velocity and the concentration of simulated raindrops along with concentrations of cation and anion.

  10. Cell culture processes for monoclonal antibody production

    OpenAIRE

    LI Feng; Vijayasankaran, Natarajan; Shen, Amy (Yijuan); Kiss, Robert; Amanullah, Ashraf

    2010-01-01

    Animal cell culture technology has advanced significantly over the last few decades and is now generally considered a reliable, robust and relatively mature technology. A range of biotherapeutics are currently synthesized using cell culture methods in large scale manufacturing facilities that produce products for both commercial use and clinical studies. The robust implementation of this technology requires optimization of a number of variables, including (1) cell lines capable of synthesizin...

  11. Harvesting energy of interaction between bacteria and bacteriophage in a membrane-less fuel cell.

    Science.gov (United States)

    Gupta, Ragini; Bekele, Wasihun; Ghatak, Animangsu

    2013-11-01

    When a fuel and oxidant flow in laminar contact through a micro-fluidic channel, a sharp interface appears between the two liquids, which eliminate the need of a proton exchange membrane. This principle has been used to generate potential in a membrane-less fuel cell. This study use such a cell to harvest energy of interaction between a bacteria having negative charge on its surface and a bacteriophage with positive and negative charges on its tail and head, respectively. When Klebsiella pneumoniae (Kp6) and phage (P-Kp6) are pumped through a fuel cell fitted with two copper electrodes placed at its two sides, interaction between these two charged species at the interface results in a constant open circuit potential which varies with concentration of charged species but gets generated for both specific and non-specific bacteria and phage system. Oxygenation of bacteria or phage however diminishes the potential unlike in conventional microbial fuel cells.

  12. The method used to culture host cells (Sf9 cells) can affect the qualities of baculovirus budding particles expressing recombinant proteins.

    Science.gov (United States)

    Hattori, Tomomi; Nakanishi, Kohei; Mori, Takaaki; Tomita, Masahiro; Tsumoto, Kanta

    2016-01-01

    Budded virus (BV) particles of baculovirus (Autographa californica nucleopolyhedrovirus, AcNPV) are harvested from the supernatant of liquid culture of Sf9 host cells by ultracentrifugation. Using polyacrylamide gel electrophoresis, Western blot and transmission electron microscopy (TEM) of BV samples fractionated closely by sucrose density gradient centrifugation, we observed that BVs exhibited different qualities depending on whether they had been harvested from the supernatant from a standing (static), shaking (suspension), or standing/shaking (pre-/post-infection) culture of Sf9 cells. The amount of BV protein apparently increased in the order of standing, standing/shaking, and shaking procedure, and the yield of intact particles showed an opposite trend. TEM observation clearly showed that appropriate fractions of the standing and standing/shaking cultures contained more intact BV particles than those from the shaking culture. These results suggest that the qualities of recombinant BV particles may be related to the culture conditions of the host cells.

  13. 3D Cell Culture in Alginate Hydrogels

    Directory of Open Access Journals (Sweden)

    Therese Andersen

    2015-03-01

    Full Text Available This review compiles information regarding the use of alginate, and in particular alginate hydrogels, in culturing cells in 3D. Knowledge of alginate chemical structure and functionality are shown to be important parameters in design of alginate-based matrices for cell culture. Gel elasticity as well as hydrogel stability can be impacted by the type of alginate used, its concentration, the choice of gelation technique (ionic or covalent, and divalent cation chosen as the gel inducing ion. The use of peptide-coupled alginate can control cell–matrix interactions. Gelation of alginate with concomitant immobilization of cells can take various forms. Droplets or beads have been utilized since the 1980s for immobilizing cells. Newer matrices such as macroporous scaffolds are now entering the 3D cell culture product market. Finally, delayed gelling, injectable, alginate systems show utility in the translation of in vitro cell culture to in vivo tissue engineering applications. Alginate has a history and a future in 3D cell culture. Historically, cells were encapsulated in alginate droplets cross-linked with calcium for the development of artificial organs. Now, several commercial products based on alginate are being used as 3D cell culture systems that also demonstrate the possibility of replacing or regenerating tissue.

  14. Insect cell culture in reagent bottles.

    Science.gov (United States)

    Rieffel, S; Roest, S; Klopp, J; Carnal, S; Marti, S; Gerhartz, B; Shrestha, B

    2014-01-01

    Growing insect cells with high air space in culture vessel is common from the early development of suspension cell culture. We believed and followed it with the hope that it allows sufficient air for optimal cell growth. However, we missed to identify how much air exactly cells need for its growth and multiplication. Here we present the innovative method that changed the way we run insect cell culture. The method is easy to adapt, cost-effective and useful for both academic and industrial research labs. We believe this method will revolutionize the way we run insect cell culture by increasing throughput in a cost-effective way. In our study we identified:•Insect cells need to be in suspension; air space in culture vessel and type of culture vessel is of less importance. Shaking condition that introduces small air bubbles and maintains it in suspension for longer time provides better oxygen transfer in liquid. For this, high-fill volume in combination with speed and shaking diameter are important.•Commercially available insect cells are not fragile as original isolates. These cells can easily withstand higher shaking speed.•Growth condition in particular lab set-up needs to be optimized. The condition used in one lab may not be optimum for another lab due to different incubators from different vendors.

  15. Pixelated speckle image holography carrier fringes for efficient superimposed light harvesting in organic solar cells

    Science.gov (United States)

    Zhou, Lei; Li, Yan-Qing; Chen, Jing-De; Ou, Qing-Dong; Tang, Jian-Xin; Zhou, Yun; Lin, Yi; Wei, Huai-Xin

    2017-06-01

    An inverted organic solar cell (OSC) device structure by incorporating pixelated speckle image holography carrier fringes (SIHFs) for efficient superimposed light harvesting is demonstrated. The proposed SIHF based OSCs yield an 18.2% increase in power conversion efficiency (PCE) compared to that of the flat control devices. Moreover, compared to the common two-dimensional (2D) periodic grating patterned OSCs, SIHF based devices achieve 7.8% higher short-circuit current (JSC) and 10.0% higher PCE. This observable improvement in PCE of SIHF based OSCs is mainly ascribed to the geometric effect due to the unique chaotic carrier fringes of SIHFs.

  16. Design of Transparent Anodes for Resonant Cavity Enhanced Light Harvesting in Organic Solar Cells

    KAUST Repository

    Sergeant, Nicholas P.

    2012-01-03

    The use of an ITO-free MoO 3/Ag/MoO 3 anode to control the photon harvesting in PCDTBT:PC 70BM solar cells is proposed. At first sight, the fact that these anodes possess reduced far-field transmission compared to ITO may seem to be a disadvantage. But, despite this, we show that by carefully tuning the resonant optical cavity we can enhance the external quantum efficiency close to the band edge of PCDTBT, resulting in high photocurrent and power conversion efficiency on par with ITO. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Data of continuous harvest of stem cells via partial detachment from thermoresponsive nanobrush surfaces

    Directory of Open Access Journals (Sweden)

    Chin-Chen Yeh

    2016-03-01

    Full Text Available This data article contains two figures and one table supporting the research article entitled: “Continuous harvest of stem cells via partial detachment from thermoresponsive nanobrush surface” [1]. The table shows coating conditions of three copolymers, poly(styrene-co-acrylic acid grafted with oligovitronectin, poly(styrene-co-N-isopropylacrylamide and poly(styrene-co-polyethylene glycol methacrylate to prepare thermoresponsive surface. XPS spectra show the nitrogen peak of the polystyrene surface coated with poly(styrene-co-acrylic acid grafted with oligovitronectin. The surface coating density analyzed from sorption of poly(styrene-co-acrylic acid grafted with oligovitronectin by UV–vis spectroscopy is also presented.

  18. Combining light-harvesting with detachability in high-efficiency thin-film silicon solar cells.

    Science.gov (United States)

    Ram, Sanjay K; Desta, Derese; Rizzoli, Rita; Bellettato, Michele; Lyckegaard, Folmer; Jensen, Pia B; Jeppesen, Bjarke R; Chevallier, Jacques; Summonte, Caterina; Larsen, Arne Nylandsted; Balling, Peter

    2017-06-01

    Efforts to realize thin-film solar cells on unconventional substrates face several obstacles in achieving good energy-conversion efficiency and integrating light-management into the solar cell design. In this report a technique to circumvent these obstacles is presented: transferability and an efficient light-harvesting scheme are combined for thin-film silicon solar cells by the incorporation of a NaCl layer. Amorphous silicon solar cells in p-i-n configuration are fabricated on reusable glass substrates coated with an interlayer of NaCl. Subsequently, the solar cells are detached from the substrate by dissolution of the sacrificial NaCl layer in water and then transferred onto a plastic sheet, with a resultant post-transfer efficiency of 9%. The light-trapping effect of the surface nanotextures originating from the NaCl layer on the overlying solar cell is studied theoretically and experimentally. The enhanced light absorption in the solar cells on NaCl-coated substrates leads to significant improvement in the photocurrent and energy-conversion efficiency in solar cells with both 350 and 100 nm thick absorber layers, compared to flat-substrate solar cells. Efficient transferable thin-film solar cells hold a vast potential for widespread deployment of off-grid photovoltaics and cost reduction.

  19. Cell culture from sponges: pluripotency and immortality.

    Science.gov (United States)

    de Caralt, Sònia; Uriz, María J; Wijffels, René H

    2007-10-01

    Sponges are a source of compounds with potential pharmaceutical applications. In this article, methods of sponge cell culture for production of these bioactive compounds are reviewed, and new approaches for overcoming the problem of metabolite supply are examined. The use of embryos is proposed as a new source of sponge material for cell culture. Stem cells are present in high amounts in embryos and are more versatile and resistant to infections than adult cells. Additionally, genetic engineering and cellular research on apoptotic mechanisms are promising new fields that might help to improve cell survival in sponge-cell lines. We propose that one topic for future research should be how to reduce apoptosis, which appears to be very high in sponge cell cultures.

  20. Rotating cell culture systems for human cell culture: human trophoblast cells as a model.

    Science.gov (United States)

    Zwezdaryk, Kevin J; Warner, Jessica A; Machado, Heather L; Morris, Cindy A; Höner zu Bentrup, Kerstin

    2012-01-18

    The field of human trophoblast research aids in understanding the complex environment established during placentation. Due to the nature of these studies, human in vivo experimentation is impossible. A combination of primary cultures, explant cultures and trophoblast cell lines support our understanding of invasion of the uterine wall and remodeling of uterine spiral arteries by extravillous trophoblast cells (EVTs), which is required for successful establishment of pregnancy. Despite the wealth of knowledge gleaned from such models, it is accepted that in vitro cell culture models using EVT-like cell lines display altered cellular properties when compared to their in vivo counterparts. Cells cultured in the rotating cell culture system (RCCS) display morphological, phenotypic, and functional properties of EVT-like cell lines that more closely mimic differentiating in utero EVTs, with increased expression of genes mediating invasion (e.g. matrix metalloproteinases (MMPs)) and trophoblast differentiation. The Saint Georges Hospital Placental cell Line-4 (SGHPL-4) (kindly donated by Dr. Guy Whitley and Dr. Judith Cartwright) is an EVT-like cell line that was used for testing in the RCCS. The design of the RCCS culture vessel is based on the principle that organs and tissues function in a three-dimensional (3-D) environment. Due to the dynamic culture conditions in the vessel, including conditions of physiologically relevant shear, cells grown in three dimensions form aggregates based on natural cellular affinities and differentiate into organotypic tissue-like assemblies. The maintenance of a fluid orbit provides a low-shear, low-turbulence environment similar to conditions found in vivo. Sedimentation of the cultured cells is countered by adjusting the rotation speed of the RCCS to ensure a constant free-fall of cells. Gas exchange occurs through a permeable hydrophobic membrane located on the back of the bioreactor. Like their parental tissue in vivo, RCCS

  1. Cell culture processes for monoclonal antibody production.

    Science.gov (United States)

    Li, Feng; Vijayasankaran, Natarajan; Shen, Amy Yijuan; Kiss, Robert; Amanullah, Ashraf

    2010-01-01

    Animal cell culture technology has advanced significantly over the last few decades and is now generally considered a reliable, robust and relatively mature technology. A range of biotherapeutics are currently synthesized using cell culture methods in large scale manufacturing facilities that produce products for both commercial use and clinical studies. The robust implementation of this technology requires optimization of a number of variables, including 1) cell lines capable of synthesizing the required molecules at high productivities that ensure low operating cost; 2) culture media and bioreactor culture conditions that achieve both the requisite productivity and meet product quality specifications; 3) appropriate on-line and off-line sensors capable of providing information that enhances process knowledge; and 4) good understanding of culture performance at different scales to ensure smooth scale-up. Successful implementation also requires appropriate strategies for process development, scale-up and process characterization and validation that enable robust operation that is compliant with current regulations. This review provides an overview of the state-of-the art technology in key aspects of cell culture, e.g., engineering of highly productive cell lines and optimization of cell culture process conditions. We also summarize the current thinking on appropriate process development strategies and process advances that might affect process development.

  2. Cell culture processes for monoclonal antibody production

    Science.gov (United States)

    Li, Feng; Vijayasankaran, Natarajan; Shen, Amy (Yijuan); Kiss, Robert

    2010-01-01

    Animal cell culture technology has advanced significantly over the last few decades and is now generally considered a reliable, robust and relatively mature technology. A range of biotherapeutics are currently synthesized using cell culture methods in large scale manufacturing facilities that produce products for both commercial use and clinical studies. The robust implementation of this technology requires optimization of a number of variables, including (1) cell lines capable of synthesizing the required molecules at high productivities that ensure low operating cost; (2) culture media and bioreactor culture conditions that achieve both the requisite productivity and meet product quality specifications; (3) appropriate on-line and off-line sensors capable of providing information that enhances process control; and (4) good understanding of culture performance at different scales to ensure smooth scale-up. Successful implementation also requires appropriate strategies for process development, scale-up and process characterization and validation that enable robust operation and ensure compliance with current regulations. This review provides an overview of the state-of-the art technology in key aspects of cell culture, e.g., generation of highly productive cell lines and optimization of cell culture process conditions. We also summarize the current thinking on appropriate process development strategies and process advances that might affect process development. PMID:20622510

  3. Characteristics of HCV replication and expression in a cultured human liver carcinoma cell line in vitro

    Institute of Scientific and Technical Information of China (English)

    SONG Zhi-qing; HAO Fei; MIN Feng; LIU Dao-jian

    2001-01-01

    Objective: To establish a cell culture system to support HCV long-term replication in vitro. Methods: A human hepatoma cell line 7721 was tested for its susceptibility to HCV by incubating with a serum from chronic hepatitis C patient. Cells and supernatant of the culture medium were harvested at various time-phases during the culturing periods. The presence of HCV RNA, the expression of HCV antigens in cells and/or supematant were examined with RT-PCR, in situ hybridization and immunohistochemistry respectively. Results: It was found that the intracellular HCV RNA was first detected on the 2nd day after culture, and then could be intermittently detected in both cells and supernatant over a period of at least 3 months after culture. HCV NS3, CP10 antigens were expressed in the cells. The fresh cells could be infected with the supernatant from cultured infected cells and the transmission of viral genome from HCV-infected 7721 cells to peripheral blood mononuclear cells (PBMCs) was also observed. Conclusion: Our findings suggest that the human liver carcinoma cell line7721 is not only susceptible to HCV but also can support its long replication in vitro. This cell line with HCV infection in vitro can serve as a useful tool for the study of the mechanism of HCV infection and replication, the evaluation of antiviral agents, and the primary selection of neutralization assays and HCV vaccine development.

  4. Periodically arranged colloidal gold nanoparticles for enhanced light harvesting in organic solar cells

    DEFF Research Database (Denmark)

    Mirsafaei, Mina; Fernandes Cauduro, André Luis; Kunstmann-Olsen, Casper

    of thinner devices without compromising light absorption. In this work, we theoretically and experimentally investigate periodically arranged colloidal gold nanoparticles in organic solar cells, and demonstrate the use of such nanostructures to improve the light absorption in and thus the efficiency...... nanostructures as well as the period of the periodical arrangements in organic bulk hetero-junction solar cells. In addition, we investigate experimentally the light absorption enhancement in the organic active layer by incorporating surface-ordered gold nanoparticle arrangements at the bottom of the organic...... active layer. The latter are fabricated with a lithography-free stamp technique, creating a centimeter scaled area with defined inter-particle spacing. Our study presents the light harvesting ability of template-assisted nanoparticle assemblies in organic solar cells and as the approach is easily...

  5. Isolation of mitochondria from tissue culture cells.

    Science.gov (United States)

    Clayton, David A; Shadel, Gerald S

    2014-10-01

    The number of mitochondria per cell varies substantially from cell line to cell line. For example, human HeLa cells contain at least twice as many mitochondria as smaller mouse L cells. This protocol starts with a washed cell pellet of 1-2 mL derived from ∼10⁹ cells grown in culture. The cells are swollen in a hypotonic buffer and ruptured with a Dounce or Potter-Elvehjem homogenizer using a tight-fitting pestle, and mitochondria are isolated by differential centrifugation. © 2014 Cold Spring Harbor Laboratory Press.

  6. The Study of the Viermicompost Influence on the Harvest and on the Quality of Forage Cultures

    Directory of Open Access Journals (Sweden)

    Larisa Cremeneac

    2011-10-01

    Full Text Available The purpose of the research was the appreciation of the viermicompost quality. This material was obtained as a result of bioconversion of organically wastes (obtained from cattle by worm cultivation, using wormculture (especially the Red Hybrid of California. The bioconversion process of organic wastes is implemented in the Experimental Section of the Scientific and Practical Institute of Biotechnologies in Animal Husbandry and Veterinary Medicine. As a result of the studies to effect in several states, including the Republic of Moldova, it has been stated that the veirmicompost has a positive influence on the productivity of cultures, diminishing the period of culture growing , increases their resistance to infavorable clamaterical conditions and to frequent phitotechnical maligns. In the agricultural production obtained as a result of cultivating on viermicompost. As a result of the research it has dean stated that the quantity of the C vitamin in some of the vegetables has increased by 1,5 – 9,4 times. What s more the viermicompost has influenced positively the quality of the alfalfa, maize and sugar fodder, in which the azoth compounds quantity has diminished by 1,32 – 2,66; 3,47 – 3,76 and 1,10 – 1,14 times, in comparison with cultures cultivars tied with the help of mineral fertilizer. So, the agricultural and ecological importance of the viermicompost consists in improving the quality of agricultural production.

  7. Floating microbial fuel cells as energy harvesters for signal transmission from natural water bodies

    Science.gov (United States)

    Schievano, Andrea; Colombo, Alessandra; Grattieri, Matteo; Trasatti, Stefano P.; Liberale, Alessandro; Tremolada, Paolo; Pino, Claudio; Cristiani, Pierangela

    2017-02-01

    A new type of floating microbial fuel cell (fMFC) was developed for power supply of remote environmental sensors and data transmission. Ten operating fMFCs generated a cell potential in the range 100-800 mV depending on the external resistance applied. Power production peaked around 3-3.5 mW (power density of 22-28 mW m-2 cathode) after about 20-30 days of start-up period. The average of daily electrical energy harvested ranged between 10 and 35 mWh/d. Long-term performances were ensured in the presence of dense rice plants (Oryza Sativa). A power management system, based on a step-up DC/DC converter and a low-power data transmission system via SIGFOX™ technology, have been set up for the fMFCs. The tested fMFCs systems allowed to: i) harvest produced energy, ii) supply electronic devices (intermittent LED-light and a buzzer); iii) transmit remote data at low speed (three message of 12 bites each, in 6 s). Several 'floating garden' MFCs were set in the context of demonstrative events at EXPO2015 world exposition held in Milan between May-October 2015. Some of the 'floating garden' MFCs were operating for more than one year.

  8. Efficiency Enhancement of InGaN-Based Solar Cells via Stacking Layers of Light-Harvesting Nanospheres

    KAUST Repository

    Al-Amri, Amal M.

    2016-06-24

    An effective light-harvesting scheme for InGaN-based multiple quantum well solar cells is demonstrated using stacking layers of polystyrene nanospheres. Light-harvesting efficiencies on the solar cells covered with varied stacks of nanospheres are evaluated through numerical and experimental methods. The numerical simulation reveals that nanospheres with 3 stacking layers exhibit the most improved optical absorption and haze ratio as compared to those obtained by monolayer nanospheres. The experimental demonstration, agreeing with the theoretical analyses, shows that the application of 3-layer nanospheres improves the conversion efficiency of the solar cell by ~31%.

  9. Culture and transfection of axolotl cells.

    Science.gov (United States)

    Denis, Jean-François; Sader, Fadi; Ferretti, Patrizia; Roy, Stéphane

    2015-01-01

    The use of cells grown in vitro has been instrumental for multiple aspects of biomedical research and especially molecular and cellular biology. The ability to grow cells from multicellular organisms like humans, squids, or salamanders is important to simplify the analyses and experimental designs to help understand the biology of these organisms. The advent of the first cell culture has allowed scientists to tease apart the cellular functions, and in many situations these experiments help understand what is happening in the whole organism. In this chapter, we describe techniques for the culture and genetic manipulation of an established cell line from axolotl, a species widely used for studying epimorphic regeneration.

  10. Toxoplasma gondii from liquid nitrogen for continuous cell culture: methods to maximise efficient retrieval.

    Science.gov (United States)

    Mavin, S; Evans, R; Chatterton, J M W; Ashburn, D; Joss, A W L; Ho-Yen, D O

    2003-01-01

    This study aims to increase the efficiency of continuous growth of Toxoplasma gondii in HeLa cells from tachyzoite stocks frozen in liquid nitrogen. Freezing and retrieval of tachyzoites for continuous cell culture requires more stringent protocols than those published for animal culture. The freezing and retrieval conditions are optimised so that a quality harvest (> or = 1 x 10(6) tachyzoites/mL, > or = 90% viability) can be produced using T. gondii recovered from liquid nitrogen as fast and reliably as possible. Retrieval success rate increased from 36% to 100%. An improved freezing procedure using chilled reagents and freshly harvested parasites, and adoption of an effective recovery protocol with retrieval of 3 x 10(7) tachyzoites into 75 cm2 flasks, change of maintenance media after six hours and subsequent blind passage all contributed to this success. The result is faster and more dependable production of T. gondii for diagnostic and experimental use.

  11. Validation of cell-free culture using scanning electron microscopy (SEM) and gene expression studies.

    Science.gov (United States)

    Yang, R; Elankumaran, Y; Hijjawi, N; Ryan, U

    2015-06-01

    A cell-free culture system for Cryptosporidium parvum was analysed using scanning electron microscopy (SEM) to characterise life cycle stages and compare gene expression in cell-free culture and cell culture using HCT-8 cells. Cryptosporidium parvum samples were harvested at 2 h, 8 h, 14 h, 26 h, 50 h, 74 h, 98 h, 122 h and 170 h, chemically fixed and specimens were observed using a Zeiss 1555 scanning electron microscope. The presence of sporozoites, trophozoites and type I merozoites were identified by SEM. Gene expression in cell culture and cell-free culture was studied using reverse transcriptase quantitative PCR (RT-qPCR) of the sporozoite surface antigen protein (cp15), the glycoprotein 900 (gp900), the Cryptosporidium oocyst wall protein (COWP) and 18S ribosomal RNA (rRNA) genes in both cell free and conventional cell culture. In cell culture, cp15 expression peaked at 74 h, gp900 expression peaked at 74 h and 98 h and COWP expression peaked at 50 h. In cell-free culture, CP15 expression peaked at 98 h, gp900 expression peaked at 74 h and COWP expression peaked at 122 h. The present study is the first to compare gene expression of C. parvum in cell culture and cell-free culture and to characterise life cycle stages of C. parvum in cell-free culture using SEM. Findings from this study showed that gene expression patterns in cell culture and cell-free culture were similar but in cell-free culture, gene expression was delayed for CP15 and COWP in cell free culture compared with the cell culture system and was lower. Although three life cycle stageswere conclusively identified, improvements in SEM methodology should lead to the detection of more life cycle stages.

  12. Stem cell harvesting protocol research in autologous transplantation setting: Large volume vs. conventional cytapheresis

    Directory of Open Access Journals (Sweden)

    Balint Bela

    2008-01-01

    Full Text Available Background/Aim. The use of peripheral blood as a source of hematopoietic stem cells (SCs is progressively increasing and has nearly supplanted bone marrow transplantation. Interpatient variability in the degree and kinetics of SC mobilization into peripheral blood is an expected event after conventional chemotherapy-based treatment, followed by sequential administration of recombinant granulocyte-colony- stimulating factor (rHu-CSF. In this study, specific factors associated with the application of two different SC-harvesting approaches, including the use of large volume leukapheresis (LVL vs. repetitive conventional apheresis (RCA, were analyzed. The basic goal of the study was to evaluate the influence of apheresis protocol (collection timing, processed blood volume and cell yield upon the clinical outcome of transplantation. Methods. Results obtained by LVL (76 pts and RCA (20 pts - control group were compared. The SC mobilizing regimen used was cyclophosphamide (4-7 g/m2 or polychemotherapy and rHuG-CSF 10-16 μg/kg of body mess (bm per day. Cell harvesting was performed using COBE-Spectra (Caridian-BCT, USA. The volume of processed blood in LVL setting was ≥ 3.5 - fold of the patient's circulating blood quantity (ranged from 12.7 to 37.8 l. All patients tolerated well the use of intensive treatment, without any side or adverse effects. Our original controlled-rate cryopreservation was carried out with 10% dimethyl sulfoxide (DMSO using Planer R203/200R or Planer 560-16 equipments (Planer Products Ltd, UK. Total nucleated cell (NC and mononuclear cell (MNC counts were examined by flow cytometry (Advia-2120 Bayer, Germany; Technicon H-3 System, USA. The CD34+ cell surface antigen was investigated by the EPICS XL-MCL device (Coulter, Germany. Results. Performing LVL-apheresis, high-level MNC and CD34+ cell yields (7.6±4.6 × 108/kg bm and 11.8±6.5 × 106/kg bm, respectively were obtained. As a result, rapid hematopoietic reconstitution

  13. Culture of Mouse Neural Stem Cell Precursors

    OpenAIRE

    Currle, D. Spencer; Hu, Jia Sheng; Kolski-Andreaco, Aaron; Monuki, Edwin S

    2007-01-01

    Primary neural stem cell cultures are useful for studying the mechanisms underlying central nervous system development. Stem cell research will increase our understanding of the nervous system and may allow us to develop treatments for currently incurable brain diseases and injuries. In addition, stem cells should be used for stem cell research aimed at the detailed study of mechanisms of neural differentiation and transdifferentiation and the genetic and environmental signals that direct the...

  14. Wound Coverage by Cultured Skin Cells

    Science.gov (United States)

    1988-11-01

    and spread. 6 We later coated collagen sponges with human or porcine plasma. Although this coating improved the plating of epidermal cells, it did not...healing by cultured epidermal grafts, we have found that: - We were able to grow epidermal cells on collapsed collagen sponges . As a result, we can create...plastic. Epidermal cells grown on collagen sponges formed four to five layers of nucleated cells, compared to only one layer on plastic surfaces. The use of

  15. Autologous peripheral blood stem cell harvest: Collection efficiency and factors affecting it

    Directory of Open Access Journals (Sweden)

    Aseem K Tiwari

    2016-01-01

    Full Text Available Background: Harvest of hematopoietic progenitor cells via leukapheresis is being used increasingly for transplants in India. Adequate yield of cells per kilogram body weight of recipient is required for successful engraftment. Collection efficiency (CE is an objective quality parameter used to assess the quality of leukapheresis program. In this study, we calculated the CE of the ComTec cell separator (Fresenius Kabi, Germany using two different formulae (CE1 and CE2 and analyzed various patient and procedural factors, which may affect it. Materials and Methods: One hundred and one consecutive procedures in 77 autologous donors carried out over 3 years period were retrospectively reviewed. Various characteristics like gender, age, weight, disease status, hematocrit, preprocedure total leukocyte count, preprocedure CD34 positive (CD34+ cells count, preprocedure absolute CD34+ cell count and processed apheresis volume effect on CE were compared. CE for each procedure was calculated using two different formulae, and results were compared using statistical correlation and regression analysis. Results: The mean CE1 and CE2 was 41.2 and 49.1, respectively. CE2 appeared to be more accurate indicator of overall CE as it considered the impact of continued mobilization of stem cells during apheresis procedure, itself. Of all the factors affecting CE, preprocedure absolute CD34+ was the only independent factor affecting CE. Conclusion: The only factor affecting CE was preprocedure absolute CD34+ cells. Though the mean CE2 was higher than CE1, it was not statistically significant.

  16. Sponge cell culture? A molecular identification method for sponge cells

    NARCIS (Netherlands)

    Sipkema, D.; Heilig, G.H.J.; Akkermans, A.D.L.; Osinga, R.; Tramper, J.; Wijffels, R.H.

    2003-01-01

    Dissociated sponge cells are easily confused with unicellular organisms. This has been an obstacle in the development of sponge-cell lines. We developed a molecular detection method to identify cells of the sponge Dysidea avara in dissociated cell cultures. The 18S ribosomal RNA gene from a Dysidea

  17. Surface modifications of photoanodes in dye sensitized solar cells: enhanced light harvesting and reduced recombination

    Science.gov (United States)

    Saxena, Vibha; Aswal, D. K.

    2015-06-01

    In a quest to harvest solar power, dye-sensitized solar cells (DSSCs) have potential for low-cost eco-friendly photovoltaic devices. The major processes which govern the efficiency of a DSSC are photoelectron generation, injection of photo-generated electrons to the conduction band (CB) of the mesoporous nanocrystalline semiconductor (nc-SC); transport of CB electrons through nc-SC and subsequent collection of CB electrons at the counter electrode (CE) through the external circuit; and dye regeneration by redox couple or hole transport layer (HTL). Most of these processes occur at various interfaces of the photoanode. In addition, recombination losses of photo-generated electrons with either dye or redox molecules take place at the interfaces. Therefore, one of the key requirements for high efficiency is to improve light harvesting of the photoanode and to reduce the recombination losses at various interfaces. In this direction, surface modification of the photoanode is the simplest method among the various other approaches available in the literature. In this review, we present a comprehensive discussion on surface modification of the photoanode, which has been adopted in the literature for not only enhancing light harvesting but also reducing recombination. Various approaches towards surface modification of the photoanode discussed are (i) fluorine-doped tin oxide (FTO)/nc-SC interface modified via a compact layer of semiconductor material which blocks exposed sites of FTO to electrolyte (or HTL), (ii) nc-SC/dye interface modification either through acid treatment resulting in enhanced dye loading due to a positively charged surface or by depositing insulating/semiconducting blocking layer on the nc-SC surface, which acts as a tunneling barrier for recombination, (iii) nc-SC/dye interface modified by employing co-adsorbents which helps in reducing the dye aggregation and thereby recombination, and (iv) dye/electrolyte (or dye/HTL) interface modification using

  18. Primary cell cultures of bovine colon epithelium: isolation and cell culture of colonocytes.

    Science.gov (United States)

    Föllmann, W; Weber, S; Birkner, S

    2000-10-01

    Epithelial cells from bovine colon were isolated by mechanical preparation combined with an enzymatic digestion from colon specimens derived from freshly slaughtered animals. After digestion with collagenase I, the isolated tissue was centrifuged on a 2% D-sorbitol gradient to separate epithelial crypts which were seeded in collagen I-coated culture flasks. By using colon crypts and omitting the seeding of single cells a contamination by fibroblasts was prevented. The cells proliferated under the chosen culture conditions and formed monolayer cultures which were maintained for several weeks, including subcultivation steps. A population doubling time of about 21 hr was estimated in the log phase of the corresponding growth curve. During the culture period the cells were characterized morphologically and enzymatically. By using antibodies against cytokeratine 7 and 13 the isolated cells were identified as cells of epithelial origin. Antibodies against vimentin served as negative control. Morphological features such as microvilli, desmosomes and tight junctions, which demonstrated the ability of the cultured cells to restore an epithelial like monolayer, were shown by ultrastructural investigations. The preservation of the secretory function of the cultured cells was demonstrated by mucine cytochemistry with alcian blue staining. A stable expression of enzyme activities over a period of 6 days in culture occurred for gamma-glutamyltranspeptidase, acid phosphatase and NADH-dehydrogenase activity under the chosen culture conditions. Activity of alkaline phosphatase decreased to about 50% of basal value after 6 days in culture. Preliminary estimations of the metabolic competence of these cells revealed cytochrome P450 1A1-associated EROD activity in freshly isolated cells which was stable over 5 days in cultured cells. Then activity decreased completely. This culture system with primary epithelial cells from the colon will be used further as a model for the colon

  19. High-performance integrated perovskite and organic solar cells with efficient near-infrared harvesting

    Science.gov (United States)

    Kim, Junghwan; Lee, Kwanghee

    2016-09-01

    The integration of planar-type perovskite (Eg 1.5 eV) solar cells (PSCs) with a bulk-heterojunction (BHJ) composite comprising a near-infrared (NIR) absorbing conjugated polymer (Eg films. Here, we successfully demonstrate highly efficient P-I-N perovskite/BHJ ISCs with an enhanced FF and improved NIR harvesting by introducing a novel n-type semiconducting polymer and a new processing additive into the BHJ films. The optimized ISCs exhibit a power conversion efficiency (PCE) of 16.36%, which far surpasses that of the reference PSCs ( 14.70%) due to the increased current density (Jsc 20.04 mA cm-2) resulting from the additional NIR harvesting. Meanwhile, the optimized ISCs maintain a high FF of 77% and an open-circuit voltage (Voc) of 1.06 V. These results indicate that this approach is a versatile means of overcoming the absorption and theoretical efficiency limits of state-ofthe- art PSCs.

  20. Human cell culture in a space bioreactor

    Science.gov (United States)

    Morrison, Dennis R.

    1988-01-01

    Microgravity offers new ways of handling fluids, gases, and growing mammalian cells in efficient suspension cultures. In 1976 bioreactor engineers designed a system using a cylindrical reactor vessel in which the cells and medium are slowly mixed. The reaction chamber is interchangeable and can be used for several types of cell cultures. NASA has methodically developed unique suspension type cell and recovery apparatus culture systems for bioprocess technology experiments and production of biological products in microgravity. The first Space Bioreactor was designed for microprocessor control, no gaseous headspace, circulation and resupply of culture medium, and slow mixing in very low shear regimes. Various ground based bioreactors are being used to test reactor vessel design, on-line sensors, effects of shear, nutrient supply, and waste removal from continuous culture of human cells attached to microcarriers. The small Bioreactor is being constructed for flight experiments in the Shuttle Middeck to verify systems operation under microgravity conditions and to measure the efficiencies of mass transport, gas transfer, oxygen consumption and control of low shear stress on cells.

  1. Flux analysis of mammalian cell culture

    NARCIS (Netherlands)

    Martens, D.E.; Tramper, J.

    2010-01-01

    Animal cells are used for the production of vaccines and pharmaceutical proteins. The increase in demand for these products requires an increase in volumetric productivity of animal cell culture processes, which can be attained through an increase in biomass concentration and/or specific productivit

  2. Xylogenesis in zinnia (Zinnia elegans) cell cultures

    NARCIS (Netherlands)

    Iakimova, Elena T.; Woltering, Ernst J.

    2017-01-01

    Main conclusion: Physiological and molecular studies support the view that xylogenesis can largely be determined as a specific form of vacuolar programmed cell death (PCD). The studies in xylogenic zinnia cell culture have led to many breakthroughs in xylogenesis research and provided a background

  3. Flux analysis of mammalian cell culture

    NARCIS (Netherlands)

    Martens, D.E.; Tramper, J.

    2010-01-01

    Animal cells are used for the production of vaccines and pharmaceutical proteins. The increase in demand for these products requires an increase in volumetric productivity of animal cell culture processes, which can be attained through an increase in biomass concentration and/or specific

  4. HEMATOPOIETIC PROGENITOR CELLS AS A PREDICTIVE OF CD34+ ENUMERATION PRIOR TO PERIPHERAL BLOOD STEM CELLS HARVESTING

    Directory of Open Access Journals (Sweden)

    Z. Zulkafli

    2014-09-01

    Full Text Available Background: To date, the CD34+ cell enumeration has relied predominantly on flow cytometry technique. However, flow cytometry is time consuming and operator dependent. The application of the hematopoietic progenitor cells (HPCs channel in Sysmex XE-2100, a fully automated hematology analyzer offers an alternative approach, which is with minimal sample manipulation and less operator dependent. This study evaluates the utility of HPC counts as a predictive of CD34+ enumeration prior to peripheral blood stem cells harvesting. Materials and methods: HPC, CD34+, white blood cell (WBC, reticulocytes (retic, immature platelet fraction (IPF and immature reticulocyte fraction (IRF were determined in 61 samples from 19 patients with hematological malignancies (15 lymphoma and 4 multiple myeloma patients at Hospital Universiti Sains Malaysia (Hospital USM who had received granulocyte-colony stimulating factor (G-CSF and planned for autologous transplantation. Results: CD34+ count showed strong and significant correlation with HPC. The receiver operating characteristics (ROC curve analysis revealed that HPC count > 21.5 x 106 / L can predicts a pre harvest CD34+ count of >20 x 106 / L with sensitivity of 77%, specificity of 64% and area under the curve (AUC of 0.802. Conclusion: We concluded that HPC count can be a useful potential parameter in optimizing timing for CD34+ enumeration prior to leukapheresis.

  5. Pitfalls in cell culture work with xanthohumol.

    Science.gov (United States)

    Motyl, M; Kraus, B; Heilmann, J

    2012-01-01

    Xanthohumol, the most abundant prenylated chalcone in hop (Humulus lupulus L.) cones, is well known to exert several promising pharmacological activities in vitro and in vivo. Among these, the chemopreventive, anti-inflammatory and anti-cancer effects are probably the most interesting. As xanthohumol is hardly soluble in water and able to undergo conversion to isoxanthohumol we determined several handling characteristics for cell culture work with this compound. Recovery experiments revealed that working with xanthohumol under cell culture conditions requires a minimal amount of 10% FCS to increase its solubility to reasonable concentrations (-50-75 micromol/l) for pharmacological in vitro tests. Additionally, more than 50% of xanthohumol can be absorbed to various plastic materials routinely used in the cell culture using FCS concentrations below 10%. In contrast, experiments using fluorescence microscopy in living cells revealed that detection of cellular intake of xanthohumol is hampered by concentrations above 1% FCS.

  6. The Effects of Sequential Environmental and Harvest Stressors on the Sensory Characteristics of Cultured Channel Catfish (Ictalurus Punctatus) Fillets.

    Science.gov (United States)

    Ciaramella, Michael A; Kim, Taejo; Avery, Jimmy L; Allen, Peter J; Schilling, M Wes

    2016-08-01

    Stress during fish culture alters physiological homeostasis and affects fillet quality. Maintenance of high-quality seafood is important to ensure the production of a marketable product. This study assessed how sequential stressors affect the sensory and quality characteristics of catfish (Ictalurus punctatus) fillets. Three stress trials were conducted where temperature (25 or 33 °C) and dissolved oxygen (DO, approximately 2.5 or >5 mg/L) were manipulated followed by socking and transport stress. After each stage of harvest (environmental stress, socking, and transport), fillet yield, consumer acceptability, descriptive evaluation, cook loss, tenderness, and pH were evaluated. Fillet yield decreased with increasing severity of environmental stress. Fillets from the severe stress treatment (33 °C, approximately 2.5 mg/L) received the highest acceptability scores (P 5 mg/L) were the least acceptable (P 6 on a 9 point scale). Socking and transport were identified to positively affect textural characteristics of catfish fillets. Although the effects observed were not likely to negatively impact consumer acceptance, a strict management plan should be followed to maintain consistency in the product and avoid changes in stressors that might alter quality more drastically.

  7. Polychlorinated biphenyls, organochlorine pesticides and trace metals in cultured and harvested bivalves from the eastern Adriatic coast (Croatia).

    Science.gov (United States)

    Milun, Vesna; Lušić, Jelena; Despalatović, Marija

    2016-06-01

    Polychlorinated biphenyls, organochlorine pesticides and trace metals were determined in tissues of bivalve molluscs (Mytilus galloprovincialis, Ostrea edulis, Venus verrucosa, Arca noae and Callista chione), collected from 11 harvesting and 2 cultured locations along the eastern Adriatic coast, in May and November 2012. Concentrations (ng g(-1) dry weight) of organochlorines ranged from 1.53 to 21.1 for PCBs and 0.68 to 5.21 for p,p'-DDTs. HCB, lindane, heptachlor and aldrin-like compounds were found in lower levels or were not detected. Metal concentrations (mg kg(-1) dry weight) ranged from 0.23 to 4.03 for Cd, 0.87-3.43 for Cr, 3.69-202.3 for Cu, 0.06-0.26 for HgT, 0.62-9.42 for Ni, 0.95-4.64 for Pb, and 55.76-4010.3 for Zn. Established organochlorine and trace metal levels were lower than the maximum allowable levels in seafood set by the European Commission.

  8. Comparison of manual and automated cultures of bone marrow stromal cells for bone tissue engineering.

    Science.gov (United States)

    Akiyama, Hirokazu; Kobayashi, Asako; Ichimura, Masaki; Tone, Hiroshi; Nakatani, Masaru; Inoue, Minoru; Tojo, Arinobu; Kagami, Hideaki

    2015-11-01

    The development of an automated cell culture system would allow stable and economical cell processing for wider clinical applications in the field of regenerative medicine. However, it is crucial to determine whether the cells obtained by automated culture are comparable to those generated by manual culture. In the present study, we focused on the primary culture process of bone marrow stromal cells (BMSCs) for bone tissue engineering and investigated the feasibility of its automation using a commercially available automated cell culture system in a clinical setting. A comparison of the harvested BMSCs from manual and automated cultures using clinically acceptable protocols showed no differences in cell yields, viabilities, surface marker expression profiles, and in vivo osteogenic abilities. Cells cultured with this system also did not show malignant transformation and the automated process was revealed to be safe in terms of microbial contamination. Taken together, the automated procedure described in this report provides an approach to clinical bone tissue engineering. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  9. Culture and Identification of Monoclonal Neural Stem Cells Derived from Cerebral Cortex

    Institute of Scientific and Technical Information of China (English)

    TAO Kaixiong; CHEN Jingbo; WANG Guobin; SHU Xiaogang

    2006-01-01

    To isolate and culture the purified monoclonal neural stem cells from the cerebral cortex of new born mice, new-born mice cerebral cortex was isolated and dissociated to single-cell suspension by mechanical trituration. The dissociated single cells were cultured in serum-free medium. After the formation of neurospheres, single-cell clone culture was performed by limiting dilution and the proliferated single-cell clones were harvested for subculture. Immunocytochemistry was used to detect the specific marker of neuroepithelial stem cells (Nestin) of the primary and monoclonal neurospheres. In the differentiated cells we detected the specific antigen of NF-200 and GFAP. Our results showed that the primary neurospheres expressed Nestin antigen positively. By limiting dilution, we cultured the cell lines from single-cell clone and the monoclonal neurospheres expressed Nestin and had capabilities of self-renewal, proliferation and the potentiality of differentiation into neurons and glial cells. It is concluded that monoclonal neural stem cells which have the ability of proliferation and multi-directional differentiation can be isolated and cultured from the cerebral cortex of new-born mice by limiting dilution.

  10. Effects of plating density and culture time on bone marrow stromal cell characteristics.

    Science.gov (United States)

    Neuhuber, Birgit; Swanger, Sharon A; Howard, Linda; Mackay, Alastair; Fischer, Itzhak

    2008-09-01

    Bone marrow stromal cells (MSC) are multipotent adult stem cells that have emerged as promising candidates for cell therapy in disorders including cardiac infarction, stroke, and spinal cord injury. While harvesting methods used by different laboratories are relatively standard, MSC culturing protocols vary widely. This study is aimed at evaluating the effects of initial plating density and total time in culture on proliferation, cell morphology, and differentiation potential of heterogeneous MSC cultures and more homogeneous cloned subpopulations. Rat MSC were plated at 20, 200, and 2000 cells/cm(2) and grown to 50% confluency. The numbers of population doublings and doubling times were determined within and across multiple passages. Changes in cell morphology and differentiation potential to adipogenic, chondrogenic, and osteogenic lineages were evaluated and compared among early, intermediate, and late passages, as well as between heterogeneous and cloned MSC populations. We found optimal cell growth at a plating density of 200 cells/cm(2). Cultures derived from all plating densities developed increased proportions of flat cells over time. Assays for chondrogenesis, osteogenesis, and adipogenesis showed that heterogeneous MSC plated at all densities sustained the potential for all three mesenchymal phenotypes through at least passage 5; the flat subpopulation lost adipogenic and chondrogenic potential. Our findings suggest that the initial plating density is not critical for maintaining a well-defined, multipotent MSC population. Time in culture, however, affects cell characteristics, suggesting that cell expansion should be limited, especially until the specific characteristics of different MSC subpopulations are better understood.

  11. Increasing cell culture population doublings for long-term growth of finite life span human cell cultures

    Science.gov (United States)

    Stampfer, Martha R; Garbe, James C

    2015-02-24

    Cell culture media formulations for culturing human epithelial cells are herein described. Also described are methods of increasing population doublings in a cell culture of finite life span human epithelial cells and prolonging the life span of human cell cultures. Using the cell culture media disclosed alone and in combination with addition to the cell culture of a compound associated with anti-stress activity achieves extended growth of pre-stasis cells and increased population doublings and life span in human epithelial cell cultures.

  12. Increasing cell culture population doublings for long-term growth of finite life span human cell cultures

    Energy Technology Data Exchange (ETDEWEB)

    Stampfer, Martha R.; Garbe, James C.

    2016-06-28

    Cell culture media formulations for culturing human epithelial cells are herein described. Also described are methods of increasing population doublings in a cell culture of finite life span human epithelial cells and prolonging the life span of human cell cultures. Using the cell culture media disclosed alone and in combination with addition to the cell culture of a compound associated with anti-stress activity achieves extended growth of pre-stasis cells and increased population doublings and life span in human epithelial cell cultures.

  13. Pinoresinol from Ipomoea cairica cell cultures.

    Science.gov (United States)

    Páska, Csilla; Innocenti, Gabbriella; Ferlin, Mariagrazia; Kunvári, Mónika; László, Miklós

    2002-10-01

    Ipomoea cairica cell cultures produced a tetrahydrofuran lignan, (+)-pinoresinol, identified by UV, IR, MS and NMR methods, not yet found in the intact plant, and new in the Convolvulaceae family. Pinoresinol was found to have antioxidant and Ca2+ antagonist properties. As it could be requested for its biological activity, we examined the possibility to raise the pinoresinol yield of I. cairica cultures, as well as we continued investigations on lignans' response to optimization.

  14. Harvest and utilization of chemical energy in wastes by microbial fuel cells.

    Science.gov (United States)

    Sun, Min; Zhai, Lin-Feng; Li, Wen-Wei; Yu, Han-Qing

    2016-05-21

    Organic wastes are now increasingly viewed as a resource of energy that can be harvested by suitable biotechnologies. One promising technology is microbial fuel cells (MFC), which can generate electricity from the degradation of organic pollutants. While the environmental benefits of MFC in waste treatment have been recognized, their potential as an energy producer is not fully understood. Although progresses in material and engineering have greatly improved the power output from MFC, how to efficiently utilize the MFC's energy in real-world scenario remains a challenge. In this review, fundamental understandings on the energy-generating capacity of MFC from real waste treatment are provided and the challenges and opportunities are discussed. The limiting factors restricting the energy output and impairing the long-term reliability of MFC are also analyzed. Several energy storage and in situ utilization strategies for the management of MFC's energy are proposed, and future research needs for real-world application of this approach are explored.

  15. Cell culture experiments planned for the space bioreactor

    Science.gov (United States)

    Morrison, Dennis R.; Cross, John H.

    1987-01-01

    Culturing of cells in a pilot-scale bioreactor remains to be done in microgravity. An approach is presented based on several studies of cell culture systems. Previous and current cell culture research in microgravity which is specifically directed towards development of a space bioprocess is described. Cell culture experiments planned for a microgravity sciences mission are described in abstract form.

  16. 21 CFR 864.2280 - Cultured animal and human cells.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cultured animal and human cells. 864.2280 Section... (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Cell And Tissue Culture Products § 864.2280 Cultured animal and human cells. (a) Identification. Cultured animal and human cells are in vitro...

  17. Impact of Co-Culturing with Fractionated Carbon-Ion-Irradiated Cancer Cells on Bystander Normal Cells and Their Progeny.

    Science.gov (United States)

    Autsavapromporn, Narongchai; Liu, Cuihua; Konishi, Teruaki

    2017-09-01

    The purpose of this study was to compare the biological effects of fractionated doses versus a single dose of high-LET carbon ions in bystander normal cells, and determine the effect on their progeny using the layered tissue co-culture system. Briefly, confluent human glioblastoma (T98G) cells received a single dose of 6 Gy or three daily doses of 2 Gy carbon ions, which were then seeded on top of an insert with bystander normal skin fibroblasts (NB1RGB) growing underneath. Cells were co-cultured for 6 h or allowed to grow for 20 population doublings, then harvested and assayed for different end points. A single dose of carbon ions resulted in less damage in bystander normal NB1RGB cells than the fractionated doses. In contrast, the progeny of bystander NB1RGB cells co-cultured with T98G cells exposed to fractionated doses showed less damage than progeny from bystander cells co-cultured with single dose glioblastoma cells. Furthermore, inhibition of gap junction communication demonstrated its involvement in the stressful effects in bystander cells and their progeny. These results indicate that dose fractionation reduced the late effect of carbon-ion exposure in the progeny of bystander cells compared to the effect in the initial bystander cells.

  18. General overview of neuronal cell culture.

    Science.gov (United States)

    Gordon, Jennifer; Amini, Shohreh; White, Martyn K

    2013-01-01

    In this introductory chapter, we provide a general overview of neuronal cell culture. This is a rapidly evolving area of research and we provide an outline and contextual framework for the different chapters of this book. These chapters were all contributed by scientists actively working in the field who are currently using state-of-the-art techniques to advance our understanding of the molecular and cellular biology of the central nervous system. Each chapter provides detailed descriptions and experimental protocols for a variety of techniques ranging in scope from basic neuronal cell line culturing to advanced and specialized methods.

  19. Advanced nanostructured materials and their application for improvement of sun-light harvesting and efficiency of solar cells

    Science.gov (United States)

    Dimova-Malinovska, D.

    2016-02-01

    This review describes the application of different nanostructured materials in solar cells technology for improvement of sun-light harvesting and their efficiency. Several approaches have recently been proposed to increase the efficiency of solar cells above the theoretical limit which are based on a “photon management” concept that employs such phenomena as: (i) down-conversion, and (ii) surface plasmon resonance effect (iii) decreasing of the loss due to the reflection of the radiation, (iv) increasing of the reflection from the back contact, v) increasing of the effective solar cells surface, etc. The results demonstrate the possibility for to increasing of light harvesting, short circuit current and efficiency by application of nanomaterials in thin film and hetero-junction (HJ) solar cells. The first promising results allow an expectation for application of advanced nanomaterials in the 3d generation solar cells.

  20. Enhanced harvesting of red photons in nanowire solar cells: evidence of resonance energy transfer.

    Science.gov (United States)

    Shankar, Karthik; Feng, Xinjian; Grimes, Craig A

    2009-04-28

    Modern excitonic solar cells efficiently harvest photons in the 350-650 nm spectral range; however, device efficiencies are typically limited by poor quantum yields for red and near-infrared photons. Using Forster-type resonance energy transfer from zinc phthalocyanine donor molecules to ruthenium polypyridine complex acceptors, we demonstrate a four-fold increase in quantum yields for red photons in dye-sensitized nanowire array solar cells. The dissolved donor and surface anchored acceptor molecules are not tethered to each other, through either a direct chemical bond or a covalent linker layer. The spatial confinement of the electrolyte imposed by the wire-to-wire spacing of the close-packed nanowire array architecture ensures that the distances between a significant fraction of donors and acceptors are within a Förster radius. The critical distance for energy transfer from an isolated donor chromophore to a self-assembled monolayer of acceptors on a plane follows the inverse fourth power instead of the inverse sixth power relation. Consequently, we observe near quantitative energy transfer efficiencies in our devices. Our results represent a new design paradigm in excitonic solar cells and show it is possible to more closely match the spectral response of the device to the AM 1.5 solar spectrum through use of electronic energy transfer.

  1. Self-powered supercapacitive microbial fuel cell: The ultimate way of boosting and harvesting power.

    Science.gov (United States)

    Santoro, Carlo; Soavi, Francesca; Serov, Alexey; Arbizzani, Catia; Atanassov, Plamen

    2016-04-15

    In this work, for the first time, we demonstrate a supercapacitive microbial fuel cell which integrates the energy harvesting function of a microbial fuel cell (MFC) with the high-power operation of an internal supercapacitor. The pursued strategies are: (i) the increase of the cell voltage by the use of high potential cathodes like bilirubin oxidase (BOx) or iron-aminoantipyrine (Fe-AAPyr); (ii) the use of an additional capacitive electrode (additional electrode, AdE) which is short-circuited with the MFC cathode and coupled with the MFC anode (MFC-AdE). The high working potential of BOx cathode and the low impedances of the additional capacitive electrode and the MFC anode permitted to achieve up to 19 mW (84.4 Wm(-2), 152 Wm(-3)), the highest power value ever reported for MFCs. Exploiting the supercapacitive properties of the MFC electrodes allows the system to be simpler, cheaper and more efficient without additional electronics management added with respect to an MFC/external supercapacitor coupling. The use of the AdE makes it possible to decouple energy and power and to achieve recharge times in the order of few seconds making the system appealing for practical applications.

  2. Harvesting Energy from Salinity Differences Using Battery Electrodes in a Concentration Flow Cell.

    Science.gov (United States)

    Kim, Taeyoung; Rahimi, Mohammad; Logan, Bruce E; Gorski, Christopher A

    2016-09-06

    Salinity-gradient energy (SGE) technologies produce carbon-neutral and renewable electricity from salinity differences between seawater and freshwater. Capacitive mixing (CapMix) is a promising class of SGE technologies that captures energy using capacitive or battery electrodes, but CapMix devices have produced relatively low power densities and often require expensive materials. Here, we combined existing CapMix approaches to develop a concentration flow cell that can overcome these limitations. In this system, two identical battery (i.e., faradaic) electrodes composed of copper hexacyanoferrate (CuHCF) were simultaneously exposed to either high (0.513 M) or low (0.017 M) concentration NaCl solutions in channels separated by a filtration membrane. The average power density produced was 411 ± 14 mW m(-2) (normalized to membrane area), which was twice as high as previously reported values for CapMix devices. Power production was continuous (i.e., it did not require a charging period and did not vary during each step of a cycle) and was stable for 20 cycles of switching the solutions in each channel. The concentration flow cell only used inexpensive materials and did not require ion-selective membranes or precious metals. The results demonstrate that the concentration flow cell is a promising approach for efficiently harvesting energy from salinity differences.

  3. Wnt-Dependent Control of Cell Polarity in Cultured Cells.

    Science.gov (United States)

    Runkle, Kristin B; Witze, Eric S

    2016-01-01

    The secreted ligand Wnt5a regulates cell polarity and polarized cell movement during development by signaling through the poorly defined noncanonical Wnt pathway. Cell polarity regulates most aspects of cell behavior including the organization of apical/basolateral membrane domains of epithelial cells, polarized cell divisions along a directional plane, and front rear polarity during cell migration. These characteristics of cell polarity allow coordinated cell movements required for tissue formation and organogenesis during embryonic development. Genetic model organisms have been used to identify multiple signaling pathways including Wnt5a that are required to establish cell polarity and regulate polarized cell behavior. However, the downstream signaling events that regulate these complex cellular processes are still poorly understood. The methods below describe assays to study Wnt5a-induced cell polarity in cultured cells, which may facilitate our understanding of these complex signaling pathways.

  4. Histology of embryoid development in oil palm (Elaeis guineensis Jacq. cell suspension culture

    Directory of Open Access Journals (Sweden)

    Songrat Tinnongjig

    2001-11-01

    Full Text Available Embryos of oil palm (Elaeis guineensis Jacq. variety tenera were cultured on Eeuwens or Y3 (1976; 1978 medium supplemented with 2 mg/l 2,4-D. Calluses were initiated from these embryos. The eight-weekold calluses derived from embryos were transferred to modified Y3 liquid medium devoid of 2,4-D and supplemented with NAA, BA and coconut water to establish cell suspension culture. After a period of culture,these cells were then subcultured to the same medium without plant growth regulators to induce embryoid formation. The calluses and embryoids were harvested at various times, fixed, sectioned, stained and examined microscopically. Histological study revealed that embryoid occurred from meristematic cells with dense cytoplasm along the callus clumps.

  5. Cell Cycle Progression of Human Cells Cultured in Rotating Bioreactor

    Science.gov (United States)

    Parks, Kelsey

    2009-01-01

    Space flight has been shown to alter the astronauts immune systems. Because immune performance is complex and reflects the influence of multiple organ systems within the host, scientists sought to understand the potential impact of microgravity alone on the cellular mechanisms critical to immunity. Lymphocytes and their differentiated immature form, lymphoblasts, play an important and integral role in the body's defense system. T cells, one of the three major types of lymphocytes, play a central role in cell-mediated immunity. They can be distinguished from other lymphocyte types, such as B cells and natural killer cells by the presence of a special receptor on their cell surface called T cell receptors. Reported studies have shown that spaceflight can affect the expression of cell surface markers. Cell surface markers play an important role in the ability of cells to interact and to pass signals between different cells of the same phenotype and cells of different phenotypes. Recent evidence suggests that cell-cycle regulators are essential for T-cell function. To trigger an effective immune response, lymphocytes must proliferate. The objective of this project is to investigate the changes in growth of human cells cultured in rotating bioreactors and to measure the growth rate and the cell cycle distribution for different human cell types. Human lymphocytes and lymphoblasts will be cultured in a bioreactor to simulate aspects of microgravity. The bioreactor is a cylindrical culture vessel that incorporates the aspects of clinostatic rotation of a solid fluid body around a horizontal axis at a constant speed, and compensates gravity by rotation and places cells within the fluid body into a sustained free-fall. Cell cycle progression and cell proliferation of the lymphocytes will be measured for a number of days. In addition, RNA from the cells will be isolated for expression of genes related in cell cycle regulations.

  6. Cell Cycle Progression of Human Cells Cultured in Rotating Bioreactor

    Science.gov (United States)

    Parks, Kelsey

    2009-01-01

    Space flight has been shown to alter the astronauts immune systems. Because immune performance is complex and reflects the influence of multiple organ systems within the host, scientists sought to understand the potential impact of microgravity alone on the cellular mechanisms critical to immunity. Lymphocytes and their differentiated immature form, lymphoblasts, play an important and integral role in the body's defense system. T cells, one of the three major types of lymphocytes, play a central role in cell-mediated immunity. They can be distinguished from other lymphocyte types, such as B cells and natural killer cells by the presence of a special receptor on their cell surface called T cell receptors. Reported studies have shown that spaceflight can affect the expression of cell surface markers. Cell surface markers play an important role in the ability of cells to interact and to pass signals between different cells of the same phenotype and cells of different phenotypes. Recent evidence suggests that cell-cycle regulators are essential for T-cell function. To trigger an effective immune response, lymphocytes must proliferate. The objective of this project is to investigate the changes in growth of human cells cultured in rotating bioreactors and to measure the growth rate and the cell cycle distribution for different human cell types. Human lymphocytes and lymphoblasts will be cultured in a bioreactor to simulate aspects of microgravity. The bioreactor is a cylindrical culture vessel that incorporates the aspects of clinostatic rotation of a solid fluid body around a horizontal axis at a constant speed, and compensates gravity by rotation and places cells within the fluid body into a sustained free-fall. Cell cycle progression and cell proliferation of the lymphocytes will be measured for a number of days. In addition, RNA from the cells will be isolated for expression of genes related in cell cycle regulations.

  7. High Harvest Yield, High Expansion, and Phenotype Stability of CD146 Mesenchymal Stromal Cells from Whole Primitive Human Umbilical Cord Tissue

    Directory of Open Access Journals (Sweden)

    Rebecca C. Schugar

    2009-01-01

    Full Text Available Human umbilical cord blood is an excellent primitive source of noncontroversial stem cells for treatment of hematologic disorders; meanwhile, new stem cell candidates in the umbilical cord (UC tissue could provide therapeutic cells for nonhematologic disorders. We show novel in situ characterization to identify and localize a panel of some markers expressed by mesenchymal stromal cells (MSCs; CD44, CD105, CD73, CD90 and CD146 in the UC. We describe enzymatic isolation and purification methods of different UC cell populations that do not require manual separation of the vessels and stroma of the coiled, helical-like UC tissue. Unique quantitation of in situ cell frequency and stromal cell counts upon harvest illustrate the potential to obtain high numerical yields with these methods. UC stromal cells can differentiate to the osteogenic and chondrogenic lineages and, under specific culturing conditions, they exhibit high expandability with unique long-term stability of their phenotype. The remarkable stability of the phenotype represents a novel finding for human MSCs, from any source, and supports the use of these cells as highly accessible stromal cells for both basic studies and potentially therapeutic applications such as allogeneic clinical use for musculoskeletal disorders.

  8. Phenotypic and functional analysis of human fetal liver hematopoietic stem cells in culture.

    Science.gov (United States)

    Rollini, Pierre; Faes-Van't Hull, Eveline; Kaiser, Stefan; Kapp, Ursula; Leyvraz, Serge

    2007-04-01

    Steady-state hematopoiesis and hematopoietic transplantation rely on the unique potential of stem cells to undergo both self-renewal and multilineage differentiation. Fetal liver (FL) represents a promising alternative source of hematopoietic stem cells (HSCs), but limited by the total cell number obtained in a typical harvest. We reported that human FL nonobese diabetic/severe combined immunodeficient (NOD/SCID) repopulating cells (SRCs) could be expanded under simple stroma-free culture conditions. Here, we sought to further characterize FL HSC/SRCs phenotypically and functionally before and following culture. Unexpanded or cultured FL cell suspensions were separated into various subpopulations. These were tested for long-term culture potential and for in vivo repopulating function following transplantation into NOD/SCID mice. We found that upon culture of human FL cells, a tight association between classical stem cell phenotypes, such as CD34(+) /CD38(-) and/or side population, and NOD/SCID repopulating function was lost, as observed with other sources. Although SRC activity before and following culture consistently correlated with the presence of a CD34(+) cell population, we provide evidence that, contrary to umbilical cord blood and adult sources, stem cells present in both CD34(+) and CD34(-) FL populations can sustain long-term hematopoietic cultures. Furthermore, upon additional culture, CD34-depleted cell suspensions, devoid of SRCs, regenerated a population of CD34(+) cells possessing SRC function. Our studies suggest that compared to neonatal and adult sources, the phenotypical characteristics of putative human FL HSCs may be less strictly defined, and reinforce the accumulated evidence that human FL represents a unique, valuable alternative and highly proliferative source of HSCs for clinical applications.

  9. Shape memory polymers for active cell culture.

    Science.gov (United States)

    Davis, Kevin A; Luo, Xiaofan; Mather, Patrick T; Henderson, James H

    2011-07-04

    Shape memory polymers (SMPs) are a class of "smart" materials that have the ability to change from a fixed, temporary shape to a pre-determined permanent shape upon the application of a stimulus such as heat(1-5). In a typical shape memory cycle, the SMP is first deformed at an elevated temperature that is higher than its transition temperature, T(trans;) [either the melting temperature (T(m;)) or the glass transition temperature (T(g;))]. The deformation is elastic in nature and mainly leads to a reduction in conformational entropy of the constituent network chains (following the rubber elasticity theory). The deformed SMP is then cooled to a temperature below its T(trans;) while maintaining the external strain or stress constant. During cooling, the material transitions to a more rigid state (semi-crystalline or glassy), which kinetically traps or "freezes" the material in this low-entropy state leading to macroscopic shape fixing. Shape recovery is triggered by continuously heating the material through T(trans;) under a stress-free (unconstrained) condition. By allowing the network chains (with regained mobility) to relax to their thermodynamically favored, maximal-entropy state, the material changes from the temporary shape to the permanent shape. Cells are capable of surveying the mechanical properties of their surrounding environment(6). The mechanisms through which mechanical interactions between cells and their physical environment control cell behavior are areas of active research. Substrates of defined topography have emerged as powerful tools in the investigation of these mechanisms. Mesoscale, microscale, and nanoscale patterns of substrate topography have been shown to direct cell alignment, cell adhesion, and cell traction forces(7-14). These findings have underscored the potential for substrate topography to control and assay the mechanical interactions between cells and their physical environment during cell culture, but the substrates used to date

  10. Microanalysis of gene expression in cultured cells

    NARCIS (Netherlands)

    E. van der Veer (Eveliene)

    1982-01-01

    textabstractIn this thesis two aspects of gene expression in cultured cells have been studied: the heterogeneity in gene expression in relation with the development and application of microchemical techniques for the prenatal diagnosis of inborn errors of metabolism and the possibility of inducing g

  11. 3D culture for cardiac cells.

    Science.gov (United States)

    Zuppinger, Christian

    2016-07-01

    This review discusses historical milestones, recent developments and challenges in the area of 3D culture models with cardiovascular cell types. Expectations in this area have been raised in recent years, but more relevant in vitro research, more accurate drug testing results, reliable disease models and insights leading to bioartificial organs are expected from the transition to 3D cell culture. However, the construction of organ-like cardiac 3D models currently remains a difficult challenge. The heart consists of highly differentiated cells in an intricate arrangement.Furthermore, electrical “wiring”, a vascular system and multiple cell types act in concert to respond to the rapidly changing demands of the body. Although cardiovascular 3D culture models have been predominantly developed for regenerative medicine in the past, their use in drug screening and for disease models has become more popular recently. Many sophisticated 3D culture models are currently being developed in this dynamic area of life science. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.

  12. Cell Culture Microfluidic Biochips: Experimental Throughput Maximization

    DEFF Research Database (Denmark)

    Minhass, Wajid Hassan; Pop, Paul; Madsen, Jan

    2011-01-01

    Microfluidic biochips offer a promising alternative to a conventional biochemical laboratory, integrating all necessary functionalities on-chip in order to perform biochemical applications. Researchers have started to propose computer-aided design tools for the synthesis of such biochips. Our focus...... metaheuristic for experimental design generation for the cell culture microfluidic biochips, and we have evaluated our approach using multiple experimental setups....

  13. Recent advances towards development and commercialization of plant cell culture processes for the synthesis of biomolecules.

    Science.gov (United States)

    Wilson, Sarah A; Roberts, Susan C

    2012-04-01

    Plant cell culture systems were initially explored for use in commercial synthesis of several high-value secondary metabolites, allowing for sustainable production that was not limited by the low yields associated with natural harvest or the high cost associated with complex chemical synthesis. Although there have been some commercial successes, most notably paclitaxel production from Taxus sp., process limitations exist with regards to low product yields and inherent production variability. A variety of strategies are being developed to overcome these limitations including elicitation, in situ product removal and metabolic engineering with single genes and transcription factors. Recently, the plant cell culture production platform has been extended to pharmaceutically active heterologous proteins. Plant systems are beneficial because they are able to produce complex proteins that are properly glycosylated, folded and assembled without the risk of contamination by toxins that are associated with mammalian or microbial production systems. Additionally, plant cell culture isolates transgenic material from the environment, allows for more controllable conditions over field-grown crops and promotes secretion of proteins to the medium, reducing downstream purification costs. Despite these benefits, the increase in cost of heterologous protein synthesis in plant cell culture as opposed to field-grown crops is significant and therefore processes must be optimized with regard to maximizing secretion and enhancing protein stability in the cell culture media. This review discusses recent advancements in plant cell culture processing technology, focusing on progress towards overcoming the problems associated with commercialization of these production systems and highlighting recent commercial successes.

  14. Nanotechnology, Cell Culture and Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Kazutoshi Haraguchi

    2011-01-01

    Full Text Available We have fabricated new types of polymer hydrogels and polymer nanocomposites, i.e., nanocomposite gels (NC gels and soft, polymer nanocomposites (M-NCs: solid, with novel organic/inorganic network structures. Both NC gels and M-NCs were synthesized by in-situ free-radical polymerization in the presence of exfoliated clay platelets in aqueous systems and were obtained in various forms such as film, sheet, tube, coating, etc. and sizes with a wide range of clay contents. Here, disk-like inorganic clay nanoparticles act as multi-functional crosslinkers to form new types of network systems. Both NC gels and M-NCs have extraordinary optical and mechanical properties including ultra-high reversible extensibility, as well as a number of new characteristics relating to optical anisotropy, polymer/clay morphology, biocompatibility, stimuli-sensitive surfaces, micro-patterning, etc. For examples, the biological testing of medical devices, comprised of a sensitization test, an irritation test, an intracutaneous test and an in vitro cytotoxicity test,was carried out for NC gels and M-NCs. The safety of NC gels and M-NCs was confirmed in all tests. Also, the interaction of living tissue with NC gel was investigated in vivo by implantation in live goats; neither inflammation nor concrescence occurred around the NC gels. Furthermore, it was found that both N-NC gels consisting of poly(N-isopropylacrylamide(PNIPA/clay network and M-NCs consisting of poly(2-methoxyethyacrylate(PMEA/clay network show characteristic cell culture and subsequent cell detachment on their surfaces, although it was almost impossible to culture cells on conventional, chemically-crosslinked PNIPA hydrogels and chemically crossslinked PMEA, regardless of their crosslinker concentration. Various kinds of cells, such ashumanhepatoma cells (HepG2, normal human dermal fibroblast (NHDF, and human umbilical vein endothelial cells (HUVEC, could be cultured to be confluent on the surfaces of N

  15. Circulating hematopoietic progenitors and CD34+ cells predicted successful hematopoietic stem cell harvest in myeloma and lymphoma patients: experiences from a single institution

    Directory of Open Access Journals (Sweden)

    Yu JT

    2016-02-01

    Full Text Available Jui-Ting Yu,1,2,* Shao-Bin Cheng,3,* Youngsen Yang,1 Kuang-Hsi Chang,4 Wen-Li Hwang,1 Chieh-Lin Jerry Teng,1,5,6 1Division of Hematology/Medical Oncology, Department of Medicine, Taichung Veterans General Hospital, 2Division of Hematology/Medical Oncology, Tungs' Taichung MetroHarbor Hospital, 3Division of General Surgery, Department of Surgery, 4Department of Medical Research and Education, Taichung Veterans General Hospital, 5Department of Life Science, Tunghai University, 6School of Medicine, Chung Shan Medical University, Taichung, Taiwan, Republic of China *These authors contributed equally to this work Background: Previous studies have shown that the numbers of both circulating hematopoietic progenitor cell (HPC and CD34+ cell are positively correlated with CD34+ cell harvest yield. However, the minimal numbers of both circulating HPCs and CD34+ cells required for performing an efficient hematopoietic stem cell (HSC harvest in lymphoma and myeloma patients have not been defined in our institution. Patients and methods: Medical records of 50 lymphoma and myeloma patients undergoing peripheral blood HSC harvest in our institution were retrospectively reviewed. The minimal and optimal HSC harvest yield required for the treatment was considered to be ≥2×106 CD34+ cells/kg and ≥5×106 CD34+ cells/kg, respectively. Results: The minimally required or optimal HSC yield obtained was not influenced by age (≥60 years, sex, underlying malignancies, disease status, multiple rounds of chemotherapy, or history of radiotherapy. The numbers of both circulating HPC and CD34+ cell were higher in patients with minimally required HSC yields (P=0.000 for HPC and P=0.000 for CD34+ cell and also in patients with optimal HSC yields (P=0.011 for HPC and P=0.006 for CD34+ cell. The cell count cutoff for obtaining minimally required HSC harvest was determined to be 20/mm3 for HPCs and 10/mm3 for CD34+ cells. Furthermore, the cell count cutoff for obtaining

  16. Cell Culture Assay for Human Noroviruses [response

    Energy Technology Data Exchange (ETDEWEB)

    Straub, Tim M.; Honer Zu Bentrup, Kerstin; Orosz Coghlan, Patricia; Dohnalkova, Alice; Mayer, Brooke K.; Bartholomew, Rachel A.; Valdez, Catherine O.; Bruckner-Lea, Cindy J.; Gerba, Charles P.; Abbaszadegan, Morteza A.; Nickerson, Cheryl A.

    2007-07-01

    We appreciate the comments provided by Leung et al., in response to our recently published article “In Vitro Cell Culture Infectivity Assay for Human Noroviruses” by Straub et al. (1). The specific aim of our project was to develop an in vitro cell culture infectivity assay for human noroviruses (hNoV) to enhance risk assessments when they are detected in water supplies. Reverse transcription (RT) qualitative or quantitative PCR are the primary assays for waterborne NoV monitoring. However, these assays cannot distinguish between infectious vs. non-infectious virions. When hNoV is detected in water supplies, information provided by our infectivity assay will significantly improve risk assessment models and protect human health, regardless of whether we are propagating NoV. Indeed, in vitro cell culture infectivity assays for the waterborne pathogen Cryptosporidium parvum that supplement approved fluorescent microscopy assays, do not result in amplification of the environmentally resistant hard-walled oocysts (2). However, identification of life cycle stages in cell culture provides evidence of infectious oocysts in a water supply. Nonetheless, Leung et al.’s assertion regarding the suitability of our method for the in vitro propagation of high titers of NoV is valid for the medical research community. In this case, well-characterized challenge pools of virus would be useful for developing and testing diagnostics, therapeutics, and vaccines. As further validation of our published findings, we have now optimized RT quantitative PCR to assess the level of viral production in cell culture, where we are indeed finding significant increases in viral titer. The magnitude and time course of these increases is dependent on both virus strain and multiplicity of infection. We are currently preparing a manuscript that will discuss these findings in greater detail, and the implications this may have for creating viral challenge pools

  17. Light harvesting proteins for solar fuel generation in bioengineered photoelectrochemical cells.

    Science.gov (United States)

    Ihssen, Julian; Braun, Artur; Faccio, Greta; Gajda-Schrantz, Krisztina; Thöny-Meyer, Linda

    2014-01-01

    The sun is the primary energy source of our planet and potentially can supply all societies with more than just their basic energy needs. Demand of electric energy can be satisfied with photovoltaics, however the global demand for fuels is even higher. The direct way to produce the solar fuel hydrogen is by water splitting in photoelectrochemical (PEC) cells, an artificial mimic of photosynthesis. There is currently strong resurging interest for solar fuels produced by PEC cells, but some fundamental technological problems need to be solved to make PEC water splitting an economic, competitive alternative. One of the problems is to provide a low cost, high performing water oxidizing and oxygen evolving photoanode in an environmentally benign setting. Hematite, α-Fe2O3, satisfies many requirements for a good PEC photoanode, but its efficiency is insufficient in its pristine form. A promising strategy for enhancing photocurrent density takes advantage of photosynthetic proteins. In this paper we give an overview of how electrode surfaces in general and hematite photoanodes in particular can be functionalized with light harvesting proteins. Specifically, we demonstrate how low-cost biomaterials such as cyanobacterial phycocyanin and enzymatically produced melanin increase the overall performance of virtually no-cost metal oxide photoanodes in a PEC system. The implementation of biomaterials changes the overall nature of the photoanode assembly in a way that aggressive alkaline electrolytes such as concentrated KOH are not required anymore. Rather, a more environmentally benign and pH neutral electrolyte can be used.

  18. Energy harvesting from organic liquids in micro-sized microbial fuel cells

    KAUST Repository

    Mink, J.E.

    2014-03-07

    Micro-sized microbial fuel cells (MFCs) are miniature energy harvesters that use bacteria to convert biomass from liquids into usable power. The key challenge is transitioning laboratory test beds into devices capable of producing high power using readily available fuel sources. Here, we present a pragmatic step toward advancing MFC applications through the fabrication of a uniquely mobile and inexpensive micro-sized device that can be fueled with human saliva. The 25-ll MFC was fabricated with graphene, a two-dimensional atomic crystal-structured material, as an anode for efficient current generation and with an air cathode for enabling the use of the oxygen present in air, making its operation completely mobile and free of the need for laboratory chemicals. With saliva as a fuel, the device produced higher current densities (1190 Am-3) than any previous aircathode micro-sized MFCs. The use of the graphene anode generated 40 times more power than that possible using a carbon cloth anode. Additional tests were performed using acetate, a conventional organic material, at high organic loadings that were comparable to those in saliva, and the results demonstrated a linear relationship between the organic loading and current. These findings open the door to saliva-powered applications of this fuel cell technology for Lab-on-a-Chip devices or portable point-of-care diagnostic devices. 2014 Nature Publishing Group All rights reserved 1884-4057/14.

  19. Three dimensional neuronal cell cultures more accurately model voltage gated calcium channel functionality in freshly dissected nerve tissue.

    Directory of Open Access Journals (Sweden)

    Yinzhi Lai

    Full Text Available It has been demonstrated that neuronal cells cultured on traditional flat surfaces may exhibit exaggerated voltage gated calcium channel (VGCC functionality. To gain a better understanding of this phenomenon, primary neuronal cells harvested from mice superior cervical ganglion (SCG were cultured on two dimensional (2D flat surfaces and in three dimensional (3D synthetic poly-L-lactic acid (PLLA and polystyrene (PS polymer scaffolds. These 2D- and 3D-cultured cells were compared to cells in freshly dissected SCG tissues, with respect to intracellular calcium increase in response to high K(+ depolarization. The calcium increases were identical for 3D-cultured and freshly dissected, but significantly higher for 2D-cultured cells. This finding established the physiological relevance of 3D-cultured cells. To shed light on the mechanism behind the exaggerated 2D-cultured cells' functionality, transcriptase expression and related membrane protein distributions (caveolin-1 were obtained. Our results support the view that exaggerated VGCC functionality from 2D cultured SCG cells is possibly due to differences in membrane architecture, characterized by uniquely organized caveolar lipid rafts. The practical implication of use of 3D-cultured cells in preclinical drug discovery studies is that such platforms would be more effective in eliminating false positive hits and as such improve the overall yield from screening campaigns.

  20. Cell Culture Microfluidic Biochips: Experimental Throughput Maximization

    DEFF Research Database (Denmark)

    Minhass, Wajid Hassan; Pop, Paul; Madsen, Jan

    2011-01-01

    Microfluidic biochips offer a promising alternative to a conventional biochemical laboratory, integrating all necessary functionalities on-chip in order to perform biochemical applications. Researchers have started to propose computer-aided design tools for the synthesis of such biochips. Our foc...... metaheuristic for experimental design generation for the cell culture microfluidic biochips, and we have evaluated our approach using multiple experimental setups....... in this paper is on the optimization of how a biochemical application is performed on a biochip. In this paper, we consider cell culture biochips, where several cell colonies are exposed to soluble compounds and monitored in real-time to determine the right combination of factors that leads to the desired...

  1. Use of an adaptable cell culture kit for performing lymphocyte and monocyte cell cultures in microgravity

    Science.gov (United States)

    Hatton, J. P.; Lewis, M. L.; Roquefeuil, S. B.; Chaput, D.; Cazenave, J. P.; Schmitt, D. A.

    1998-01-01

    The results of experiments performed in recent years on board facilities such as the Space Shuttle/Spacelab have demonstrated that many cell systems, ranging from simple bacteria to mammalian cells, are sensitive to the microgravity environment, suggesting gravity affects fundamental cellular processes. However, performing well-controlled experiments aboard spacecraft offers unique challenges to the cell biologist. Although systems such as the European 'Biorack' provide generic experiment facilities including an incubator, on-board 1-g reference centrifuge, and contained area for manipulations, the experimenter must still establish a system for performing cell culture experiments that is compatible with the constraints of spaceflight. Two different cell culture kits developed by the French Space Agency, CNES, were recently used to perform a series of experiments during four flights of the 'Biorack' facility aboard the Space Shuttle. The first unit, Generic Cell Activation Kit 1 (GCAK-1), contains six separate culture units per cassette, each consisting of a culture chamber, activator chamber, filtration system (permitting separation of cells from supernatant in-flight), injection port, and supernatant collection chamber. The second unit (GCAK-2) also contains six separate culture units, including a culture, activator, and fixation chambers. Both hardware units permit relatively complex cell culture manipulations without extensive use of spacecraft resources (crew time, volume, mass, power), or the need for excessive safety measures. Possible operations include stimulation of cultures with activators, separation of cells from supernatant, fixation/lysis, manipulation of radiolabelled reagents, and medium exchange. Investigations performed aboard the Space Shuttle in six different experiments used Jurkat, purified T-cells or U937 cells, the results of which are reported separately. We report here the behaviour of Jurkat and U937 cells in the GCAK hardware in ground

  2. Dynamic cell culture system (7-IML-1)

    Science.gov (United States)

    Cogoli, Augusto

    1992-01-01

    This experiment is one of the Biorack experiments being flown on the International Microgravity Laboratory 1 (MIL-1) mission as part of an investigation studying cell proliferation and performance in space. One of the objectives of this investigation is to assess the potential benefits of bioprocessing in space with the ultimate goal of developing a bioreactor for continuous cell cultures in space. This experiment will test the operation of an automated culture chamber that was designed for use in a Bioreactor in space. The device to be tested is called the Dynamic Cell Culture System (DCCS). It is a simple device in which media are renewed or chemicals are injected automatically, by means of osmotic pumps. This experiment uses four Type I/O experiment containers. One DCCS unit, which contains a culture chamber with renewal of medium and a second chamber without a medium supply fits in each container. Two DCCS units are maintained under zero gravity conditions during the on-orbit period. The other two units are maintained under 1 gh conditions in a 1 g centrifuge. The schedule for incubator transfer is given.

  3. Isolation and culture of human umbilical vein endothelial cells (HUVEC).

    Science.gov (United States)

    Cheung, Ambrose L

    2007-02-01

    Human-derived endothelial cells can now be routinely harvested from human umbilical veins. Studies with human umbilical vein endothelial cells (HUVEC) have been conducted with cells from passage 2 to 5. It is now also possible to cryopreserve primary and early-passaged HUVEC for future propagation and for forwarding to an end user by express courier. Stored HUVEC have been stably retrieved even after several years. These retrieval techniques have facilitated the deployment of HUVEC for many studies, including those for homeostasis, inflammatory disorders, atherosclerosis, cancer, and microbial adhesion and invasion. In this unit, we will delineate the procedure for harvesting, propagation, and storage of HUVEC.

  4. Culturing of retinal pigment epithelium cells.

    Science.gov (United States)

    Valtink, Monika; Engelmann, Katrin

    2009-01-01

    The retinal pigment epithelium (RPE) is a monolayer of cells adjacent to the photoreceptors of the retina. It plays a crucial role in maintaining photoreceptor health and survival. Degeneration or dysfunction of the RPE can lead to photoreceptor degeneration and as a consequence to visual impairment. The most common diseased state of the RPE becomes manifest in age-related macular degeneration, an increasing cause of blindness in the elderly. RPE cells are therefore of great interest to researchers working in the field of tissue engineering and cell transplantation. In fact, studies in animal models have proven that the transplantation of RPE cells can delay the course of photoreceptor degenerative diseases. Although first attempts to transplant RPE cells into the subretinal space in human individuals suffering from age-related macular degeneration were less successful, RPE cell transplantation is still favored as a future therapeutic option, and much work is done to develop and design cell transplants. Cell banking is a prerequisite to have well-differentiated and characterized cells at hand when needed for research purposes, but also for therapeutic approaches. In this chapter the authors will describe methods to isolate, culture and preserve adult human RPE cells for the purpose of RPE cell banking. Copyright 2009 S. Karger AG, Basel.

  5. Prevention and Detection of Mycoplasma Contamination in Cell Culture

    Directory of Open Access Journals (Sweden)

    Parvaneh Farzaneh

    2012-01-01

    Full Text Available One of the main problems in cell culture is mycoplasma infection. It can extensively affectcell physiology and metabolism. As the applications of cell culture increase in research,industrial production and cell therapy, more concerns about mycoplasma contaminationand detection will arise. This review will provide valuable information about: 1. the waysin which cells are contaminated and the frequency and source of mycoplasma species incell culture; 2. the ways to prevent mycoplasma contamination in cell culture; 3. the importanceof mycoplasma tests in cell culture; 4. different methods to identify mycoplasmacontamination; 5. the consequences of mycoplasma contamination in cell culture and 6.available methods to eliminate mycoplasma contamination. Awareness about the sourcesof mycoplasma and pursuing aseptic techniques in cell culture along with reliable detectionmethods of mycoplasma contamination can provide an appropriate situation to preventmycoplasma contamination in cell culture.

  6. Silkworm (Bombyx mori) hemolymph unable to substitute fetal bovine serum in insect cell culture

    Science.gov (United States)

    Suparto, Irma H.; Khalam, Chandra Nur; Praira, Willy; Sajuthi, Dondin

    2014-03-01

    Fetal Bovine Serum (FBS) in animal cell culture media is an important source of nutrients for cell growth. However, the harvest and collection of FBS cause bioethical concerns. Efforts to reduce and preferably replace FBS with synthetic or other natural alternatives are continually being explored. Hemolymph silkworm (Bombyx mori) contains many nutrients needed for the process of metamorphosis. Therefore, there is possibility as an alternative nutritional supplement for cell culture to reduce the use of FBS. The objective of this study was to evaluate the macrocomponent of hemolymph and the possibility as medium supplement for Spodoptera fugiperda (Sf9) cell culture. Proximate analyses showed that hemolymph contains 89.76% of water, 2.52 mg/mL carbohydrate, 2.35% fat and 55.61 mg/mL protein. Further protein analysis, it consists of 15 fractions containing molecular weight of 22 - 152 kDa. The use of hemolymph as FBS substitution in Sf9 cell culture with various concentrations was unable to maintain and support cell growth. Further research still needed by prior adaptation of the tissue culture to minimal nutrition media before introduction of the hemolymph as supplement.

  7. Human ES cells: starting culture from frozen cells.

    Science.gov (United States)

    Trish, Erin; Dimos, John; Eggan, Kevin

    2006-11-09

    Here we demonstrate how our lab begins a HuES human embryonic stem cell line culture from a frozen stock. First, a one to two day old ten cm plate of approximately one (to two) million irradiated mouse embryonic fibroblast feeder cells is rinsed with HuES media to remove residual serum and cell debris, and then HuES media added and left to equilibrate in the cell culture incubator. A frozen vial of cells from long term liquid nitrogen storage or a -80 C freezer is sourced and quickly submerged in a 37 C water bath for quick thawing. Cells in freezing media are then removed from the vial and placed in a large volume of HuES media. The large volume of HuES media facilitates removal of excess serum and DMSO, which can cause HuES human embryonic stem cells to differentiate. Cells are gently spun out of suspension, and then re-suspended in a small volume of fresh HuES media that is then used to seed the MEF plate. It is considered important to seed the MEF plate by gently adding the HuES cells in a drop wise fashion to evenly disperse them throughout the plate. The newly established HuES culture plate is returned to the incubator for 48 hrs before media is replaced, then is fed every 24 hours thereafter.

  8. Intelligent energy harvesting scheme for microbial fuel cells: Maximum power point tracking and voltage overshoot avoidance

    Science.gov (United States)

    Alaraj, Muhannad; Radenkovic, Miloje; Park, Jae-Do

    2017-02-01

    Microbial fuel cells (MFCs) are renewable and sustainable energy sources that can be used for various applications. The MFC output power depends on its biochemical conditions as well as the terminal operating points in terms of output voltage and current. There exists one operating point that gives the maximum possible power from the MFC, maximum power point (MPP), for a given operating condition. However, this MPP may vary and needs to be tracked in order to maintain the maximum power extraction from the MFC. Furthermore, MFC reactors often develop voltage overshoots that cause drastic drops in the terminal voltage, current, and the output power. When the voltage overshoot happens, an additional control measure is necessary as conventional MPPT algorithms will fail because of the change in the voltage-current relationship. In this paper, the extremum seeking (ES) algorithm was used to track the varying MPP and a voltage overshoot avoidance (VOA) algorithm is developed to manage the voltage overshoot conditions. The proposed ES-MPPT with VOA algorithm was able to extract 197.2 mJ during 10-min operation avoiding voltage overshoot, while the ES MPPT-only scheme stopped harvesting after only 18.75 mJ because of the voltage overshoot happened at 0.4 min.

  9. Enhanced bioelectricity harvesting in microbial fuel cells treating food waste leachate produced from biohydrogen fermentation.

    Science.gov (United States)

    Choi, Jeongdong; Ahn, Youngho

    2015-05-01

    Microbial fuel cells (MFCs) treating the food waste leachate produced from biohydrogen fermentation were examined to enhance power generation and energy recovery. In batch mode, the maximum voltage production was 0.56 V and the power density reached 1540 mW/m(2). The maximum Coulombic efficiency (CEmax) and energy efficiency (EE) in the batch mode were calculated to be 88.8% and 18.8%, respectively. When the organic loading rate in sequencing batch mode varied from 0.75 to 6.2 g COD/L-d (under CEmax), the maximum power density reached 769.2 mW/m(2) in OLR of 3.1 g COD/L-d, whereas higher energy recovery (CE=52.6%, 0.346 Wh/g CODrem) was achieved at 1.51 g COD/L-d. The results demonstrate that readily biodegradable substrates in biohydrogen fermentation can be effectively used for the enhanced bioelectricity harvesting of MFCs and a MFC coupled with biohydrogen fermentation is of great benefit on higher electricity generation and energy efficiency.

  10. Energy transfer in nanowire solar cells with photon-harvesting shells

    KAUST Repository

    Peters, C. H.

    2009-01-01

    The concept of a nanowire solar cell with photon-harvesting shells is presented. In this architecture, organic molecules which absorb strongly in the near infrared where silicon absorbs weakly are coupled to silicon nanowires (SiNWs). This enables an array of 7-μm -long nanowires with a diameter of 50 nm to absorb over 85% of the photons above the bandgap of silicon. The organic molecules are bonded to the surface of the SiNWs forming a thin shell. They absorb the low-energy photons and subsequently transfer the energy to the SiNWs via Förster resonant energy transfer, creating free electrons and holes within the SiNWs. The carriers are then separated at a radial p-n junction in a nanowire and extracted at the respective electrodes. The shortness of the nanowires is expected to lower the dark current due to the decrease in p-n junction surface area, which scales linearly with wire length. The theoretical power conversion efficiency is 15%. To demonstrate this concept, we measure a 60% increase in photocurrent from a planar silicon-on-insulator diode when a 5 nm layer of poly[2-methoxy-5-(2′ -ethyl-hexyloxy)-1,4-phenylene vinylene is applied to the surface of the silicon. This increase is in excellent agreement with theoretical predictions. © 2009 American Institute of Physics.

  11. Mouse cell culture - Methods and protocols

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-12-01

    Full Text Available The mouse is, out of any doubt, the experimental animal par excellence for many many colleagues within the scientific community, notably for those working in mammalian biology (in a broad sense, from basic genetic to modeling human diseases, starting at least from 1664 Robert Hooke experiments on air’s propertyn. Not surprising then that mouse cell cultures is a well established field of research itself and that there are several handbooks devoted to this discipline. Here, Andrew Ward and David Tosh provide a necessary update of the protocols currently needed. In fact, nearly half of the book is devoted to stem cells culture protocols, mainly embryonic, from a list of several organs (kidney, lung, oesophagus and intestine, pancreas and liver to mention some........

  12. Sequencing technologies for animal cell culture research.

    Science.gov (United States)

    Kremkow, Benjamin G; Lee, Kelvin H

    2015-01-01

    Over the last 10 years, 2nd and 3rd generation sequencing technologies have made the use of genomic sequencing within the animal cell culture community increasingly commonplace. Each technology's defining characteristics are unique, including the cost, time, sequence read length, daily throughput, and occurrence of sequence errors. Given each sequencing technology's intrinsic advantages and disadvantages, the optimal technology for a given experiment depends on the particular experiment's objective. This review discusses the current characteristics of six next-generation sequencing technologies, compares the differences between them, and characterizes their relevance to the animal cell culture community. These technologies are continually improving, as evidenced by the recent achievement of the field's benchmark goal: sequencing a human genome for less than $1,000.

  13. Mouse cell culture: methods and protocols

    OpenAIRE

    Elvira M. Guerra Shinohara

    2010-01-01

    The mouse is, out of any doubt, the experimental animal par excellence for many many colleagues within the scientific community, notably for those working in mammalian biology (in a broad sense, from basic genetic to modeling human diseases), starting at least from 1664 Robert Hooke experiments on air’s propertyn. Not surprising then that mouse cell cultures is a well established field of research itself and that there are several handbooks devoted to this discipline. Here, Andrew Ward ...

  14. Embryo forming cells in carrot suspension cultures.

    OpenAIRE

    Toonen, M.A.J.

    1997-01-01

    Somatic cells of many plant species can be cultured in vitro and induced to form embryos that are able to develop into mature plants. This process, termed somatic embryogenesis, was originally described in carrot (Daucus carota L.). Somatic embryos develop through the same characteristic morphological stages, i.e. the globular-, heartand torpedo-stage respectively, as their zygotic counterparts. Due to the different cellular origin of somatic embryos, it is less clear to what extent the earli...

  15. PHYTOCHEMICAL STUDY OF CELL CULTURE JATROPHA CURCAS

    OpenAIRE

    KOMAR RUSLAN; ARTRI; ELFAHMI

    2011-01-01

    Jatropha curcas belongs to the Euphorbiaceae family which has potential economically. This plant has been reported to contain toxic compounds such as curcin and phorbol ester and its derivatives. These compounds may become a problem if J. curcas will be explored as a source of biofuel. In order to provide safety plants, the research on the study of phytochemical and initiation of cell and organ culture have been carried out. J curcas which has been collected from different regions in Indonesi...

  16. Culture of human mesenchymal stem cells on microcarriers in a 5 l stirred-tank bioreactor.

    Science.gov (United States)

    Rafiq, Qasim A; Brosnan, Kathryn M; Coopman, Karen; Nienow, Alvin W; Hewitt, Christopher J

    2013-08-01

    For the first time, fully functional human mesenchymal stem cells (hMSCs) have been cultured at the litre-scale on microcarriers in a stirred-tank 5 l bioreactor, (2.5 l working volume) and were harvested via a potentially scalable detachment protocol that allowed for the successful detachment of hMSCs from the cell-microcarrier suspension. Over 12 days, the dissolved O2 concentration was >45 % of saturation and the pH between 7.2 and 6.7 giving a maximum cell density in the 5 l bioreactor of 1.7 × 10(5) cells/ml; this represents >sixfold expansion of the hMSCs, equivalent to that achievable from 65 fully-confluent T-175 flasks. During this time, the average specific O2 uptake of the cells in the 5 l bioreactor was 8.1 fmol/cell h and, in all cases, the 5 l bioreactors outperformed the equivalent 100 ml spinner-flasks run in parallel with respect to cell yields and growth rates. In addition, yield coefficients, specific growth rates and doubling times were calculated for all systems. Neither the upstream nor downstream bioprocessing unit operations had a discernible effect on cell quality with the harvested cells retaining their immunophenotypic markers, key morphological features and differentiation capacity.

  17. A prospective randomised controlled trial to investigate the effect of local anaesthetic in vivo on cell culture.

    Science.gov (United States)

    Mary O'Brien, C; Breuning, Eleonore; Webb, Jill; Balderson, Debra; Nancarrow, Jeffrey

    2008-10-01

    Cell culture is an important adjunct in the management of major burns in that it enables keratinocytes derived from the patient to be grown and used to attain cover when there is little autologous skin available. The purpose of this prospective randomised trial was to determine if the type of local anaesthetic used to harvest the skin biopsy in vivo affected the subsequent culture of keratinocytes. Lignocaine 1% was compared with a eutectic mixture of local anaesthetic (EMLA) and a control. The subjects recruited were patients undergoing abdominoplasty. Sixteen patients were recruited but two were excluded from final analysis due to infection of the culture medium in one and poor yield from biopsies in all groups in the other. The tissue to be removed from the abdomen was divided into three areas. EMLA was applied to a 5x5 cm randomised area 2 h prior to surgery. Lignocaine 1% was injected into a 5x5 cm randomised area of abdominal skin immediately after anaesthesia. The third 5x5 cm randomised area was used as a control. Three 4-mm punch biopsies were harvested from each site of local anaesthetic application as well as the control area. The Rheinwald & Green method was used to culture these cells [Rheinwald JG, Green H. Serial cultivation of strains of human epidermal keratinocytes: the formation of keratinizing colonies from single cells. Cell 1975;6:331-5.] Cell counts were performed after harvesting keratinocytes from the biopsy and after 10 days of culture. Statistical analysis was undertaken. In conclusion, in contrast to in vitro studies when lignocaine 1% or EMLA is applied in vivo, there is no inhibition of cell culture. In vivo EMLA was also found to significantly increase cell multiplication.

  18. A Versatile Bioreactor for Dynamic Suspension Cell Culture. Application to the Culture of Cancer Cell Spheroids.

    Science.gov (United States)

    Massai, Diana; Isu, Giuseppe; Madeddu, Denise; Cerino, Giulia; Falco, Angela; Frati, Caterina; Gallo, Diego; Deriu, Marco A; Falvo D'Urso Labate, Giuseppe; Quaini, Federico; Audenino, Alberto; Morbiducci, Umberto

    2016-01-01

    A versatile bioreactor suitable for dynamic suspension cell culture under tunable shear stress conditions has been developed and preliminarily tested culturing cancer cell spheroids. By adopting simple technological solutions and avoiding rotating components, the bioreactor exploits the laminar hydrodynamics establishing within the culture chamber enabling dynamic cell suspension in an environment favourable to mass transport, under a wide range of tunable shear stress conditions. The design phase of the device has been supported by multiphysics modelling and has provided a comprehensive analysis of the operating principles of the bioreactor. Moreover, an explanatory example is herein presented with multiphysics simulations used to set the proper bioreactor operating conditions for preliminary in vitro biological tests on a human lung carcinoma cell line. The biological results demonstrate that the ultralow shear dynamic suspension provided by the device is beneficial for culturing cancer cell spheroids. In comparison to the static suspension control, dynamic cell suspension preserves morphological features, promotes intercellular connection, increases spheroid size (2.4-fold increase) and number of cycling cells (1.58-fold increase), and reduces double strand DNA damage (1.5-fold reduction). It is envisioned that the versatility of this bioreactor could allow investigation and expansion of different cell types in the future.

  19. An improved protocol for isolation and culture of mesenchymal stem cells from mouse bone marrow

    Directory of Open Access Journals (Sweden)

    Shuo Huang

    2015-01-01

    Full Text Available Mesenchymal stem cells (MSCs from bone marrow are main cell source for tissue repair and engineering, and vehicles of cell-based gene therapy. Unlike other species, mouse bone marrow derived MSCs (BM-MSCs are difficult to harvest and grow due to the low MSCs yield. We report here a standardised, reliable, and easy-to-perform protocol for isolation and culture of mouse BM-MSCs. There are five main features of this protocol. (1 After flushing bone marrow out of the marrow cavity, we cultured the cells with fat mass without filtering and washing them. Our method is simply keeping the MSCs in their initial niche with minimal disturbance. (2 Our culture medium is not supplemented with any additional growth factor. (3 Our method does not need to separate cells using flow cytometry or immunomagnetic sorting techniques. (4 Our method has been carefully tested in several mouse strains and the results are reproducible. (5 We have optimised this protocol, and list detailed potential problems and trouble-shooting tricks. Using our protocol, the isolated mouse BM-MSCs were strongly positive for CD44 and CD90, negative CD45 and CD31, and exhibited tri-lineage differentiation potentials. Compared with the commonly used protocol, our protocol had higher success rate of establishing the mouse BM-MSCs in culture. Our protocol may be a simple, reliable, and alternative method for culturing MSCs from mouse bone marrow tissues.

  20. Conversion of primordial germ cells to pluripotent stem cells: methods for cell tracking and culture conditions.

    Science.gov (United States)

    Nagamatsu, Go; Suda, Toshio

    2013-01-01

    Primordial germ cells (PGCs) are unipotent cells committed to germ lineage: PGCs can only differentiate into gametes in vivo. However, upon fertilization, germ cells acquire the capacity to differentiate into all cell types in the body, including germ cells. Therefore, germ cells are thought to have the potential for pluripotency. PGCs can convert to pluripotent stem cells in vitro when cultured under specific conditions that include bFGF, LIF, and the membrane-bound form of SCF (mSCF). Here, the culture conditions which efficiently convert PGCs to pluripotent embryonic germ (EG) cells are described, as well as methods used for identifying pluripotent candidate cells during culture.

  1. Wild Harvests from Scottish Woodlands Social, cultural and economic values of contemporary non-timber forest products

    Science.gov (United States)

    Marla Emery; Suzanne Martin; Alison Dyke; Alison Dyke

    2006-01-01

    More than 30 people were interviewed about the wild edibles, medicinals, and craft materials they collect and the part that collecting plays in their lives as part of the Wild Harvests from Scottish Woodlands project. Interviews were conducted in autumn 2004. Collecting non-timber forest products (NTFPs) is a source of joy and satisfaction for many of those interviewed...

  2. High-Performance Integrated Perovskite and Organic Solar Cells with Enhanced Fill Factors and Near-Infrared Harvesting.

    Science.gov (United States)

    Kim, Junghwan; Kim, Geunjin; Back, Hyungcheol; Kong, Jaemin; Hwang, In-Wook; Kim, Tae Kyun; Kwon, Sooncheol; Lee, Jong-Hoon; Lee, Jinho; Yu, Kilho; Lee, Chang-Lyoul; Kang, Hongkyu; Lee, Kwanghee

    2016-04-01

    Highly efficient P-I-N type perovskite/bulk-heterojunction (BHJ) integrated solar cells (ISCs) with enhanced fill factor (FF) (≈80%) and high near-infrared harvesting (>30%) are demonstrated by optimizing the BHJ morphology with a novel n-type polymer, N2200, and a new solvent-processing additive. This work proves the feasibility of highly efficient ISCs with panchromatic absorption as a new photovoltaic architecture and provides important design rules for optimizing ISCs.

  3. An Introductory Undergraduate Course Covering Animal Cell Culture Techniques

    Science.gov (United States)

    Mozdziak, Paul E.; Petitte, James N.; Carson, Susan D.

    2004-01-01

    Animal cell culture is a core laboratory technique in many molecular biology, developmental biology, and biotechnology laboratories. Cell culture is a relatively old technique that has been sparingly taught at the undergraduate level. The traditional methodology for acquiring cell culture training has been through trial and error, instruction when…

  4. An Introductory Undergraduate Course Covering Animal Cell Culture Techniques

    Science.gov (United States)

    Mozdziak, Paul E.; Petitte, James N.; Carson, Susan D.

    2004-01-01

    Animal cell culture is a core laboratory technique in many molecular biology, developmental biology, and biotechnology laboratories. Cell culture is a relatively old technique that has been sparingly taught at the undergraduate level. The traditional methodology for acquiring cell culture training has been through trial and error, instruction when…

  5. Cell response of Chlamydomonas actinochloris culture to repeated microwave irradiation

    Directory of Open Access Journals (Sweden)

    OLESIA O. GRYGORIEVA

    2015-05-01

    Full Text Available Abstract. Grygorieva OO, Berezovsjka MA, Dacenko OI. 2015. Cell response of Chlamydomonas actinochloris culture to repeated microwave irradiation. Nusantara Bioscience 7: 38-42. Two cultures of Chlamydomonas actinochloris Deason et Bold in the lag-phase were exposed to the microwave irradiation. One of them (culture 1 was not treated beforehand, whereas the other (culture 2 was irradiated by microwaves 2 years earlier. The measurement of cell quantity as well as measurement of change of intensities and spectra of cultures photoluminescence (PL in the range of chlorophyll a emission was regularly conducted during the cell cultures development. Cell concentration of culture 1 exposed to the microwave irradiation for the first time has quickly restored while cell concentration of culture 2 which was irradiated repeatedly has fallen significantly. The following increasing of cell concentration of culture 2 is negligible. Cell concentration reaches the steady-state level that is about a half of the cell concentration of control culture. Initially the PL efficiency of cells of both cultures decreases noticeable as a result of irradiation. Then there is the monotonic increase to the values which are significantly higher than the corresponding values in the control cultures. The ratio of the intensities at the maxima of the main emission bands of chlorophyll for control samples of both cultures remained approximately at the same level. At the same time effect of irradiation on the cell PL spectrum appears as a temporary reduction of this magnitude.

  6. Boosting Photon Harvesting in Organic Solar Cells with Highly Oriented Molecular Crystals via Graphene-Organic Heterointerface.

    Science.gov (United States)

    Jo, Sae Byeok; Kim, Hyun Ho; Lee, Hansol; Kang, Boseok; Lee, Seongkyu; Sim, Myungsun; Kim, Min; Lee, Wi Hyoung; Cho, Kilwon

    2015-08-25

    Photon harvesting in organic solar cells is highly dependent on the anisotropic nature of the optoelectronic properties of photoactive materials. Here, we demonstrate an efficient approach to dramatically enhance photon harvesting in planar heterojunction solar cells by using a graphene-organic heterointerface. A large area, residue-free monolayer graphene is inserted at anode interface to serve as an atomically thin epitaxial template for growing highly orientated pentacene crystals with lying-down orientation. This anisotropic orientation enhances the overall optoelectronic properties, including light absorption, charge carrier lifetime, interfacial energetics, and especially the exciton diffusion length. Spectroscopic and crystallographic analysis reveal that the lying-down orientation persists until a thickness of 110 nm, which, along with increased exciton diffusion length up to nearly 100 nm, allows the device optimum thickness to be doubled to yield significantly enhanced light absorption within the photoactive layers. The resultant photovoltaic performance shows simultaneous increment in Voc, Jsc, and FF, and consequently a 5 times increment in the maximum power conversion efficiency than the equivalent devices without a graphene layer. The present findings indicate that controlling organic-graphene heterointerface could provide a design strategy of organic solar cell architecture for boosting photon harvesting.

  7. Flow perfusion culture of human mesenchymal stem cells on coralline hydroxyapatite scaffolds with various pore sizes.

    Science.gov (United States)

    Bjerre, Lea; Bünger, Cody; Baatrup, Anette; Kassem, Moustapha; Mygind, Tina

    2011-06-01

    Bone grafts are widely used in orthopaedic reconstructive surgery, but harvesting of autologous grafts is limited due to donor site complications. Bone tissue engineering is a possible alternative source for substitutes, and to date, mainly small scaffold sizes have been evaluated. The aim of this study was to obtain a clinically relevant substitute size using a direct perfusion culture system. Human bone marrowderived mesenchymal stem cells were seeded on coralline hydroxyapatite scaffolds with 200 μm or 500 μm pores, and resulting constructs were cultured in a perfusion bioreactor or in static culture for up to 21 days and analysed for cell distribution and osteogenic differentiation using histological stainings, alkaline phosphatase activity assay, and real-time RT-PCR on bone markers. We found that the number of cells was higher during static culture at most time points and that the final number of cells was higher in 500 μm constructs as compared with 200 μm constructs. Alkaline phosphatase enzyme activity assays and real time RT-PCR on seven osteogenic markers showed that differentiation occurred primarily and earlier in statically cultured constructs with 200 μm pores compared with 500 μm ones. Adhesion and proliferation of the cells was seen on both scaffold sizes, but the vitality and morphology of cells changed unfavorably during perfusion culture. In contrast to previous studies using spinner flask that show increased cellularity and osteogenic properties of cells when cultured dynamically, the perfusion culture in our study did not enhance the osteogenic properties of cell/scaffold constructs. The statically cultured constructs showed increasing cell numbers and abundant osteogenic differentiation probably because of weak initial cell adhesion due to the surface morphology of scaffolds. Our conclusion is that the specific scaffold surface microstructure and culturing system flow dynamics has a great impact on cell distribution and proliferation

  8. Insect cell culture in research: Indian scenario.

    Science.gov (United States)

    Sudeep, A B; Mourya, D T; Mishra, A C

    2005-06-01

    Insect cell cultures are widely used in viral diagnosis and biotechnology, for the production of recombinant proteins, viral pesticides and vaccines as well as in basic research in genetics, molecular biology, biochemistry, endocrinology and virology. Following KRP Singh's pioneering research in 1967, a large number of cell lines from diptera, hemiptera, and lepidopteran insects were established and characterized in India. With the availability of the modern tools in molecular biology and the advancements made in biotechnology, the indigenous cell lines may prove useful in creating a future without biohazardous chemical pesticides as well as producing life saving pharmaceuticals and vaccines for many diseases. This review summarizes information gathered regarding the insect cell lines established so far in India. It also covers the familiarization of the well characterized continuous cell lines and their potential applications. Special attention is given to virus susceptibility of the cell lines, the yield of virus with a comparative analysis with other conventional systems. The potential applications of dipteran and lepidopteran cell lines in agriculture and biotechnology are also briefly discussed for prospective studies.

  9. Cell culture device using spatial light modulator

    Science.gov (United States)

    Ou, Chung-Jen; Shen, Ching-I.; Ou, Chung-Ming

    2009-07-01

    Spatial light modulator is introduced for cell culturing and related illumination experiment. Two kinds of designs were used. The first type put the cell along with the bio-medium directly on top of the analyzer of the microdisplay and set a cover glass on it to retain the medium environment, which turned the microdisplay into a bio-container. The second type introduced an optical lens system placed below the spatial light modulator to focus the light spots on specific position. Details of the advantages and drawbacks for the two different approaches are discussed, and the human melanocyte cell (HMC) is introduced to prove the feasibility of the concept. Results indicate that the second type is much more suitable than the first for precision required application.

  10. Rapid method for culturing embryonic neuron-glial cell cocultures

    DEFF Research Database (Denmark)

    Svenningsen, Åsa Fex; Shan, Wei-Song; Colman, David R;

    2003-01-01

    A streamlined, simple technique for primary cell culture from E17 rat tissue is presented. In an attempt to standardize culturing methods for all neuronal cell types in the embryo, we evaluated a commercial medium without serum and used similar times for trypsinization and tested different surfaces...... for plating. In 1 day, using one method and a single medium, it is possible to produce robust E17 cultures of dorsal root ganglia (DRG), cerebellum, and enteric plexi. Allowing the endogenous glial cells to repopulate the cultures saves time compared with existing techniques, in which glial cells are added...... to cultures first treated with antimitotic agents. It also ensures that all the cells present in vivo will be present in the culture. Myelination commences after approximately 2 weeks in culture for dissociated DRG and 3-4 weeks in cerebellar cultures. In enteric cultures, glial wrapping of the enteric...

  11. Effect of processing, post-harvest irradiation, and production system on the cytotoxicity and mutagenicity of Vitis labrusca L. juices in HTC cells.

    Directory of Open Access Journals (Sweden)

    Elisângela Düsman

    Full Text Available The juices of grapes (Vitis labrusca L. are similar to the fruit itself because the main constituents of the fruit are present in the juice. However, their quality characteristics may be modified by the harsh technological processes used for the production of integral food, such as production systems of raw materials and post-harvest treatment of grapes with ultraviolet (UV irradiation. Therefore, the present study analyzed juices produced naturally (by liquefying the fruit or by the technological process of extraction by steam distillation (90°C of grapes from organic and conventional production systems that were untreated or treated with UV type C (65.6 J/m² for 10 minutes. Using cultures of Rattus norvegicus hepatoma cells (HTC in vitro, cytotoxic effects were assayed by the MTT test and by calculating the cytokinesis blocked proliferation index (CBPI, and mutagenic effects were measured by the cytokinesis block micronucleus assay. The results of the MTT assay and the CBPIs indicated that none of the juices were cytotoxic, including those that induced cell proliferation. The results of the micronucleus assay showed that none of the juices were mutagenic. However, the average number of micronuclei was lower in the juices produced from organic grapes, and cell proliferation, soluble acids and phenolic compounds were significantly higher. Compared with the natural juices, the integral juices of conventional grapes showed a higher average number of micronuclei as well as lower stimulation of cell proliferation and lower levels of bioactive compounds. The results demonstrate a beneficial effect of UV-C irradiation of post-harvest grapes in stimulating the synthesis of nutraceutical compounds without generating cytotoxic or mutagenic substances. Taken together, our findings support the consumption of grape juice and the application of food production techniques that enhance its nutritional value and promote its production, marketing and

  12. Effect of processing, post-harvest irradiation, and production system on the cytotoxicity and mutagenicity of Vitis labrusca L. juices in HTC cells.

    Science.gov (United States)

    Düsman, Elisângela; de Almeida, Igor Vivian; Lucchetta, Luciano; Vicentini, Veronica Elisa Pimenta

    2014-01-01

    The juices of grapes (Vitis labrusca L.) are similar to the fruit itself because the main constituents of the fruit are present in the juice. However, their quality characteristics may be modified by the harsh technological processes used for the production of integral food, such as production systems of raw materials and post-harvest treatment of grapes with ultraviolet (UV) irradiation. Therefore, the present study analyzed juices produced naturally (by liquefying the fruit) or by the technological process of extraction by steam distillation (90°C) of grapes from organic and conventional production systems that were untreated or treated with UV type C (65.6 J/m² for 10 minutes). Using cultures of Rattus norvegicus hepatoma cells (HTC) in vitro, cytotoxic effects were assayed by the MTT test and by calculating the cytokinesis blocked proliferation index (CBPI), and mutagenic effects were measured by the cytokinesis block micronucleus assay. The results of the MTT assay and the CBPIs indicated that none of the juices were cytotoxic, including those that induced cell proliferation. The results of the micronucleus assay showed that none of the juices were mutagenic. However, the average number of micronuclei was lower in the juices produced from organic grapes, and cell proliferation, soluble acids and phenolic compounds were significantly higher. Compared with the natural juices, the integral juices of conventional grapes showed a higher average number of micronuclei as well as lower stimulation of cell proliferation and lower levels of bioactive compounds. The results demonstrate a beneficial effect of UV-C irradiation of post-harvest grapes in stimulating the synthesis of nutraceutical compounds without generating cytotoxic or mutagenic substances. Taken together, our findings support the consumption of grape juice and the application of food production techniques that enhance its nutritional value and promote its production, marketing and consumption.

  13. PHYTOCHEMICAL STUDY OF CELL CULTURE JATROPHA CURCAS

    Directory of Open Access Journals (Sweden)

    KOMAR RUSLAN

    2011-01-01

    Full Text Available Jatropha curcas belongs to the Euphorbiaceae family which has potential economically. This plant has been reported to contain toxic compounds such as curcin and phorbol ester and its derivatives. These compounds may become a problem if J. curcas will be explored as a source of biofuel. In order to provide safety plants, the research on the study of phytochemical and initiation of cell and organ culture have been carried out. J curcas which has been collected from different regions in Indonesia showed to contain relatively the same profile of chemical contents. Dominant compounds that were detected by GCMS are hidrocarbon such as 2-heptenal, decadienal, hexsadecane, pentadecane, cyclooctane etc, fatty acid such as oktadecanoate acid, etthyl linoleate, ethyl stearate, heksadecanoate acid and steroid such as stigmasterol, fucosterol, sitosterol. No phorbol ester and its derivatives have been detected yet by the GCMS method. Callus and suspension cultures of J. curcas have been established to be used for further investigation.

  14. Primary Adult Human Retinal Pigment Epithelial Cell Cultures on Human Amniotic Membranes

    Directory of Open Access Journals (Sweden)

    Singhal Shweta

    2005-01-01

    Full Text Available Purpose: Retinal pigment epithelial (RPE cells grow well on surfaces that provide an extracellular matrix. Our aim was to establish primary adult human RPE cell cultures that retain their epithelial morphology in vitro using human amniotic membrane (hAM as substrate. Materials and Methods: Human cadaver eyeballs (16 were obtained from the eye bank after corneal trephination. RPE cells were harvested by a mechanical dissection of the inner choroid surface (10, group 1 or by b enzymatic digestion using 0.25% Trypsin/0.02% EDTA (6, group 2. The cells were explanted onto de-epithelialized hAM, nourished using DMEM/HAMS F-12 media and monitored for growth under the phase contrast microscope. Cell cultures were characterised by whole mount studies and paraffin sections. Growth data in the two groups were compared using the students′ ′t′ test. Results: Eleven samples (68.75% showed positive cultures with small, hexagonal cells arising from around the explant which formed a confluent and progressively pigmented monolayer. Whole mounts showed closely placed polygonal cells with heavily pigmented cytoplasm and indistinct nuclei. The histologic sections showed monolayers of cuboidal epithelium with variable pigmentation within the cytoplasm. Growth was seen by day 6-23 (average 11.5 days in the mechanical group, significantly earlier ( P Conclusions: Primary adult human RPE cell cultures retain epithelial morphology in vitro when cultured on human amniotic membranes . Mechanical dissection of the inner choroid surface appears to be an effective method of isolating RPE cells and yields earlier growth in cultures as compared to isolation by enzymatic digestion

  15. How do culture media influence in vitro perivascular cell behavior?

    Science.gov (United States)

    Huber, Birgit; Volz, Ann-Cathrin; Kluger, Petra Juliane

    2015-12-01

    Perivascular cells are multilineage cells located around the vessel wall and important for wall stabilization. In this study, we evaluated a stem cell media and a perivascular cell-specific media for the culture of primary perivascular cells regarding their cell morphology, doubling time, stem cell properties, and expression of cell type-specific markers. When the two cell culture media were compared to each other, perivascular cells cultured in the stem cell medium had a more elongated morphology and a faster doubling rate and cells cultured in the pericyte medium had a more typical morphology, with several filopodia, and a slower doubling rate. To evaluate stem cell properties, perivascular cells, CD146(-) cells, and mesenchymal stem cells (MSCs) were differentiated into the adipogenic, osteogenic, and chondrogenic lineages. It was seen that perivascular cells, as well as CD146(-) cells and MSCs, cultured in stem cell medium showed greater differentiation than cells cultured in pericyte-specific medium. The expression of pericyte-specific markers CD146, neural/glial antigen 2 (NG2), platelet-derived growth factor receptor-β (PDGFR-β), myosin, and α-smooth muscle actin (α-SMA) could be found in both pericyte cultures, as well as to varying amounts in CD146(-) cells, MSCs, and endothelial cells. The here presented work shows that perivascular cells can adapt to their in vitro environment and cell culture conditions influence cell functionality, such as doubling rate or differentiation behavior. Pericyte-specific markers were shown to be expressed also from cells other than perivascular cells. We can further conclude that CD146(+) perivascular cells are inhomogeneous cell population probably containing stem cell subpopulations, which are located perivascular around capillaries.

  16. Good cell culture practices &in vitro toxicology.

    Science.gov (United States)

    Eskes, Chantra; Boström, Ann-Charlotte; Bowe, Gerhard; Coecke, Sandra; Hartung, Thomas; Hendriks, Giel; Pamies, David; Piton, Alain; Rovida, Costanza

    2017-04-25

    Good Cell Culture Practices (GCCP) is of high relevance to in vitro toxicology. The European Society of Toxicology In Vitro (ESTIV), the Center for Alternatives for Animal Testing (CAAT) and the In Vitro Toxicology Industrial Platform (IVTIP) joined forces to address by means of an ESTIV 2016 pre-congress session the different aspects and applications of GCCP. The covered aspects comprised the current status of the OECD guidance document on Good In Vitro Method Practices, the importance of quality assurance for new technological advances in in vitro toxicology including stem cells, and the optimized implementation of Good Manufacturing Practices and Good Laboratory Practices for regulatory testing purposes. General discussions raised the duality related to the difficulties in implementing GCCP in an academic innovative research framework on one hand, and on the other hand, the need for such GCCP principles in order to ensure reproducibility and robustness of in vitro test methods for toxicity testing. Indeed, if good cell culture principles are critical to take into consideration for all uses of in vitro test methods for toxicity testing, the level of application of such principles may depend on the stage of development of the test method as well as on the applications of the test methods, i.e., academic innovative research vs. regulatory standardized test method. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Cryptosporidium cell culture infectivity assay design.

    Science.gov (United States)

    King, B J; Keegan, A R; Robinson, B S; Monis, P T

    2011-05-01

    Members of the genus Cryptosporidium, which cause the gastrointestinal disease cryptosporidiosis, still represent a significant cause of water-borne disease worldwide. While intensive efforts have been invested in the development of techniques for parasite culture, in vitro growth has been hampered by a number of factors including low levels of infectivity as well as delayed life-cycle development and poor synchronicity. In this study we examined factors affecting the timing of contact between excysted sporozoites and target host cells and the subsequent impact of this upon the establishment of infection. We demonstrate that excystation rate impacts upon establishment of infection and that in our standard assay format the majority of sporozoites are not close enough to the cell monolayer when they are released from the oocyst to successfully establish infection. However, this can be easily overcome by centrifugation of oocysts onto the cell monolayer, resulting in approximately 4-fold increases in sporozoite attachment and subsequent infection. We further demonstrate that excystation procedures can be tailored to control excystation rate to match the assay end purpose and that excystation rate can influence data interpretation. Finally, the addition of both a centrifugation and washing step post-sporozoite attachment may be appropriate when considering the design of in vitro culture experiments for developmental analysis and stage-specific gene expression as this appears to increase the synchronicity of early developmental stages.

  18. Sarcoma derived from cultured mesenchymal stem cells.

    Science.gov (United States)

    Tolar, Jakub; Nauta, Alma J; Osborn, Mark J; Panoskaltsis Mortari, Angela; McElmurry, Ron T; Bell, Scott; Xia, Lily; Zhou, Ning; Riddle, Megan; Schroeder, Tania M; Westendorf, Jennifer J; McIvor, R Scott; Hogendoorn, Pancras C W; Szuhai, Karoly; Oseth, Leann; Hirsch, Betsy; Yant, Stephen R; Kay, Mark A; Peister, Alexandra; Prockop, Darwin J; Fibbe, Willem E; Blazar, Bruce R

    2007-02-01

    To study the biodistribution of MSCs, we labeled adult murine C57BL/6 MSCs with firefly luciferase and DsRed2 fluorescent protein using nonviral Sleeping Beauty transposons and coinfused labeled MSCs with bone marrow into irradiated allogeneic recipients. Using in vivo whole-body imaging, luciferase signals were shown to be increased between weeks 3 and 12. Unexpectedly, some mice with the highest luciferase signals died and all surviving mice developed foci of sarcoma in their lungs. Two mice also developed sarcomas in their extremities. Common cytogenetic abnormalities were identified in tumor cells isolated from different animals. Original MSC cultures not labeled with transposons, as well as independently isolated cultured MSCs, were found to be cytogenetically abnormal. Moreover, primary MSCs derived from the bone marrow of both BALB/c and C57BL/6 mice showed cytogenetic aberrations after several passages in vitro, showing that transformation was not a strain-specific nor rare event. Clonal evolution was observed in vivo, suggesting that the critical transformation event(s) occurred before infusion. Mapping of the transposition insertion sites did not identify an obvious transposon-related genetic abnormality, and p53 was not overexpressed. Infusion of MSC-derived sarcoma cells resulted in malignant lesions in secondary recipients. This new sarcoma cell line, S1, is unique in having a cytogenetic profile similar to human sarcoma and contains bioluminescent and fluorescent genes, making it useful for investigations of cellular biodistribution and tumor response to therapy in vivo. More importantly, our study indicates that sarcoma can evolve from MSC cultures.

  19. External nitrogen input affects pre- and post-harvest cell wall composition but not the enzymatic saccharification of wheat straw

    DEFF Research Database (Denmark)

    Baldwin, Laetitia Andrée; Glazowska, Sylwia Emilia; Mravec, Jozef

    2017-01-01

    Wheat is one of the most important crops for food and feed and its straw is a potential feedstock for biorefinery purposes. Nitrogen (N) is an essential input factor in wheat agriculture but no information is available on how it affects straw composition during maturation and at harvest. To inves......Wheat is one of the most important crops for food and feed and its straw is a potential feedstock for biorefinery purposes. Nitrogen (N) is an essential input factor in wheat agriculture but no information is available on how it affects straw composition during maturation and at harvest....... To investigate this, we conducted a large scale field experiment in which wheat plants were cultivated at three levels of externally applied N. The plants were harvested at different stages of maturation, spanning green straw at heading (ear emergence) to fully yellow straw at final maturity. Defined parts...... of the straw were analyzed for cell wall characteristics relevant for further biomass processing. The straw N concentration corroborated with the level of N input, but the yield of straw biomass was not largely affected. High N treatment modified cell wall composition, namely increased abundance...

  20. DNA MUTAGENESIS IN PANAX GINSENG CELL CULTURES

    Directory of Open Access Journals (Sweden)

    Kiselev K.V.

    2012-08-01

    Full Text Available At the present time, it is well documented that plant tissue culture induces a number of mutations and chromosome rearrangements termed “somaclonal variations”. However, little is known about the nature and the molecular mechanisms of the tissue culture-induced mutagenesis and the effects of long-term subculturing on the rate and specific features of the mutagenesis. The aim of the present study was to investigate and compare DNA mutagenesis in different genes of Panax ginseng callus cultures of different age. It has previously been shown that the nucleotide sequences of the Agrobacterium rhizogenes rolC locus and the selective marker nptII developed mutations during long-term cultivation of transgenic cell cultures of P. ginseng. In the present work, we analyzed nucleotide sequences of selected plant gene families in a 2-year-old and 20-year-old P. ginseng 1c cell culture and in leaves of cultivated P. ginseng plants. We analysed sequence variability between the Actin genes, which are a family of house-keeping genes; the phenylalanine ammonia-lyase (PAL and dammarenediol synthase (DDS genes, which actively participate in the biosynthesis of ginsenosides; and the somatic embryogenesis receptor kinase (SERK genes, which control plant development. The frequency of point mutations in the Actin, PAL, DDS, and SERK genes in the 2-year-old callus culture was markedly higher than that in cultivated plants but lower than that in the 20-year-old callus culture of P. ginseng. Most of the mutations in the 2- and 20-year-old P. ginseng calli were A↔G and T↔C transitions. The number of nonsynonymous mutations was higher in the 2- and 20-year-old callus cultures than the number of nonsynonymous mutations in the cultivated plants of P. ginseng. Interestingly, the total number of N→G or N→C substitutions in the analyzed genes was 1.6 times higher than the total number of N→A or N→T substitutions. Using methylation-sensitive DNA fragmentation

  1. Quantification of nucleated cells, CD34-positive cells and CFU-GM colonies in single bone marrow samples and bone marrow harvests derived from healthy children.

    Science.gov (United States)

    Schündeln, Michael M; Walde, Gabriele; Basu, Oliver; Havers, Werner; Kremens, Bernhard

    2014-05-01

    Little is known regarding bone marrow (BM) cellularity, CD34+ fraction, and CFU-GM colony formation in relation to age and whether healthy children require a reference range distinct from healthy adults. We therefore analyzed a series of single BM aspirates from 45 healthy children who were evaluated as potential BM donors. Thirty-three of these children subsequently donated BM. We quantified the nucleated cell count, fraction of CD34+ cells, and number of CFU-GM colonies in single aspirates and BM harvests. Single aspirates displayed a mean nucleated cell count of 31.3 × 10(6) cells/mL, a mean fraction of 1.17% CD34+ cells, and a mean colony forming potential of 66.6 CFU-GM/10(5) cells. Harvests yielded the same number of nucleated cells but increased numbers of CD34+ cells and CFU-GM compared with single aspirates. The mean nucleated cell count in BM harvests was 31.1 × 10(6) /mL with a mean fraction of 1.95% CD34+ cells and a mean of 112.4 CFU-GM colonies/10(5) cells. The concentration of nucleated cells was elevated compared with reported adult counts, while CD34+ percentage and CFU-GM counts were similar. In this series of healthy children, the fraction of CD34+ cells, CFU-GM colonies, and nucleated cells decreased with age. We did not identify gender specific differences. To our knowledge, this represents the first comprehensive study of CD34+ cell fraction, CFU-GM counts, and nucleated cell numbers in the BM of healthy children. The findings provide valuable information for practical use for BM transplantation and contribute to the understanding of hematopoiesis from birth to adulthood.

  2. Growth of cultured porcine retinal pigment epithelial cells

    DEFF Research Database (Denmark)

    Wiencke, A.K.; Kiilgaard, Jens Folke; Nicolini, Jair;

    2003-01-01

    To establish and characterize cultures of porcine retinal pigment epithelial (pRPE) cells in order to produce confluent monolayers of cells for transplantation.......To establish and characterize cultures of porcine retinal pigment epithelial (pRPE) cells in order to produce confluent monolayers of cells for transplantation....

  3. Equipment for large-scale mammalian cell culture.

    Science.gov (United States)

    Ozturk, Sadettin S

    2014-01-01

    This chapter provides information on commonly used equipment in industrial mammalian cell culture, with an emphasis on bioreactors. The actual equipment used in the cell culture process can vary from one company to another, but the main steps remain the same. The process involves expansion of cells in seed train and inoculation train processes followed by cultivation of cells in a production bioreactor. Process and equipment options for each stage of the cell culture process are introduced and examples are provided. Finally, the use of disposables during seed train and cell culture production is discussed.

  4. Cultured circulating tumor cells and their derived xenografts for personalized oncology

    Directory of Open Access Journals (Sweden)

    Ruoxiang Wang

    2016-10-01

    Full Text Available Recent cancer research has demonstrated the existence of circulating tumor cells (CTCs in cancer patient's blood. Once identified, CTC biomarkers will be invaluable tools for clinical diagnosis, prognosis and treatment. In this review, we propose ex vivo culture as a rational strategy for large scale amplification of the limited numbers of CTCs from a patient sample, to derive enough CTCs for accurate and reproducible characterization of the biophysical, biochemical, gene expressional and behavioral properties of the harvested cells. Because of tumor cell heterogeneity, it is important to amplify all the CTCs in a blood sample for a comprehensive understanding of their role in cancer metastasis. By analyzing critical steps and technical issues in ex vivo CTC culture, we developed a cost-effective and reproducible protocol directly culturing whole peripheral blood mononuclear cells, relying on an assumed survival advantage in CTCs and CTC-like cells over the normal cells to amplify this specified cluster of cancer cells.

  5. The effect of varying type and volume of sedimenting agents on leukocyte harvesting and labelling in sickle cell patients

    Energy Technology Data Exchange (ETDEWEB)

    Webber, D.; Nunan, T.O.; O' Doherty, M.J. (Guys and Saint Thomas' s Hospital Trust, London (United Kingdom))

    1994-09-01

    Leukocyte labelling in patients with sickle cell anaemia has been reported as difficult if not impossible due to the slow erythrocyte sedimentation rate (ESR) in these patients. This study investigated standard sedimentation methods in patients with sickle cell disease (n=16) and compared the results obtained with those following changes in the amount and type of sedimenting agent used. Labelling with either [sup 111]In-oxine or [sup 99]Tc[sup m]-exametazime was attempted in only five patients. Replacement of the commonly used 6% Hetastarch (Hespan) with Dextran or Haemaccel did not improve leukocyte harvesting, even when the proportions used of these agents were increased. In most cases where standard procedures for leukocyte collection did not lead to harvesting of viable samples, it was possible to collect reasonably pure samples by increasing the proportion of Hespan used. It is possible to obtain adequate leukocyte labelling in the majority of sickle cell patients using a minor modification of standard techniques. In this group of patients a ratio of 8 ml of Hespan to 16 ml of blood should be used for cell separation. If this fails then donor cells, anti-granulocyte antibody labelling or HIG should be considered. (author).

  6. Modelling of Mammalian cells and cell culture processes.

    Science.gov (United States)

    Sidoli, F R; Mantalaris, A; Asprey, S P

    2004-01-01

    Mammalian cell cultures represent the major source for a number of very high-value biopharmaceutical products, including monoclonal antibodies (MAbs), viral vaccines, and hormones. These products are produced in relatively small quantities due to the highly specialised culture conditions and their susceptibility to either reduced productivity or cell death as a result of slight deviations in the culture conditions. The use of mathematical relationships to characterise distinct parts of the physiological behaviour of mammalian cells and the systematic integration of this information into a coherent, predictive model, which can be used for simulation, optimisation, and control purposes would contribute to efforts to increase productivity and control product quality. Models can also aid in the understanding and elucidation of underlying mechanisms and highlight the lack of accuracy or descriptive ability in parts of the model where experimental and simulated data cannot be reconciled. This paper reviews developments in the modelling of mammalian cell cultures in the last decade and proposes a future direction - the incorporation of genomic, proteomic, and metabolomic data, taking advantage of recent developments in these disciplines and thus improving model fidelity. Furthermore, with mammalian cell technology dependent on experiments for information, model-based experiment design is formally introduced, which when applied can result in the acquisition of more informative data from fewer experiments. This represents only part of a broader framework for model building and validation, which consists of three distinct stages: theoretical model assessment, model discrimination, and model precision, which provides a systematic strategy from assessing the identifiability and distinguishability of a set of competing models to improving the parameter precision of a final validated model.

  7. Solar cells on CMOS chips as energy harvesters - integration and CMOS compatibility

    NARCIS (Netherlands)

    Lu, Jiwu

    2011-01-01

    Energy harvesting is an interesting topic in the 21st century for electrical engineers from both industry and academia. It will be a core technology for autonomous wireless networks, which is the essential component of the long-lived ubiquitous computing world. There are different ways to achieve th

  8. Recombinant Protein Production and Insect Cell Culture and Process

    Science.gov (United States)

    Spaulding, Glenn F. (Inventor); Goodwin, Thomas J. (Inventor); OConnor, Kim C. (Inventor); Francis, Karen M. (Inventor); Andrews, Angela D. (Inventor); Prewett, Tracey L. (Inventor)

    1997-01-01

    A process has been developed for recombinant production of selected polypeptides using transformed insect cells cultured in a horizontally rotating culture vessel modulated to create low shear conditions. A metabolically transformed insect cell line is produced using the culture procedure regardless of genetic transformation. The recombinant polypeptide can be produced by an alternative process using virtually infected or stably transformed insect cells containing a gene encoding the described polypeptide. The insect cells can also be a host for viral production.

  9. Luminescent solar concentrators and all-inorganic nanoparticle solar cells for solar energy harvesting

    Science.gov (United States)

    Sholin, Veronica

    Increasing energy demand and the parallel increase of greenhouse gas emissions are challenging researchers to find new and cleaner energy sources. Solar energy harvesting is arguably the most promising candidate for replacing fossil-fuel power generation. Photovoltaics are the most direct way of collecting solar energy; cost continues to hinder large-scale implementation of photovoltaics, however. Therefore, alternative technologies that will allow the extraction of solar power, while maintaining the overall costs of fabrication, installation, collection, and distribution low, must be explored. This thesis focuses on the fabrication and testing of two types of devices that step up to this challenge: the luminescent solar concentrator (LSC) and all-inorganic nanoparticle solar cells. In these devices I make use of novel materials, semiconducting polymers and inorganic nanoparticles, both of which have lower costs than the crystalline materials used in the fabrication of traditional photovoltaics. Furthermore, the cost of manufacturing LSCs and the nanoparticle solar cells is lower than the manufacturing cost of traditional optics-based concentrators and crystalline solar cells. An LSC is essentially a slab of luminescent material that acts as a planar light pipe. The LSC absorbs incoming photons and channels fluoresced photons toward appropriately located solar cells, which perform the photovoltaic conversion. By covering large areas with relatively inexpensive fluorescing organic dyes or semiconducting polymers, the area of solar cell needed is greatly reduced. Because semiconducting polymers and quantum dots may have small absorption/emission band overlaps, tunable absorption, and longer lifetimes, they are good candidates for LSC fabrication, promising improvement with respect to laser dyes traditionally used to fabricate LSCs. Here the efficiency of LSCs consisting of liquid solutions of semiconducting polymers encased in glass was measured and compared to the

  10. Quality of harvest and role of cell dose in unrelated bone marrow transplantation: an Italian Bone Marrow Donor Registry-Gruppo Italiano Trapianto di Midollo Osseo Study.

    Science.gov (United States)

    Fagioli, Franca; Quarello, Paola; Pollichieni, Simona; Lamparelli, Teresa; Berger, Massimo; Benedetti, Fabio; Barat, Veronica; Marciano, Renato; Rambaldi, Alessandro; Bacigalupo, Andrea; Sacchi, Nicoletta

    2014-01-01

    In this study, we investigated the factors affecting cell dose harvest and the role of cell dose on outcome. We analysed data from a cohort of 703 patients who underwent unrelated bone marrow transplantation facilitated by IBMDR in GITMO centers between 2002 and 2008. The median-infused cell doses is 3.7 × 10(8)/kg, the correlation between the nucleated cells requested from transplant centers and those harvested by collection centers was adequate. A harvested/requested cells ratio lower than 0.5 was observed only in 3% of harvests. A volume of harvested marrow higher than the median value of 1270 ml was related to a significant lower infused cell dose (χ(2): 44.4; P < 0.001). No patient- or donor-related variables significantly influenced the cell dose except for the recipient younger age (χ(2): 95.7; P < 0.001) and non-malignant diseases (χ(2): 33.8; P < 0.001). The cell dose resulted an independent predictor factor for a better outcome in patients affected by non-malignant disease (P = 0.05) while early disease malignant patients receiving a lower cell dose showed a higher risk of relapse (P = 0.05).

  11. PCR-Based Multiple Species Cell Counting for In Vitro Mixed Culture.

    Directory of Open Access Journals (Sweden)

    Ruijie Huang

    Full Text Available Changes of bacterial profiles in microbial communities are strongly associated with human health. There is an increasing need for multiple species research in vitro. To avoid high cost or measurement of a limited number of species, PCR-based multiple species cell counting (PCR-MSCC has been conceived. Species-specific sequence is defined as a unique sequence of one species in a multiple species mixed culture. This sequence is identified by comparing a random 1000 bp genomic sequence of one species with the whole genome sequences of the other species in the same artificial mixed culture. If absent in the other genomes, it is the species-specific sequence. Species-specific primers were designed based on the species-specific sequences. In the present study, ten different oral bacterial species were mixed and grown in Brain Heart Infusion Yeast Extract with 1% sucrose for 24 hours. Biofilm was harvested and processed for DNA extraction and q-PCR amplification with the species-specific primers. By comparing the q-PCR data of each species in the unknown culture with reference cultures, in which the cell number of each species was determined by colony forming units on agar plate, the cell number of that strain in the unknown mixed culture was calculated. This technique is reliable to count microorganism numbers that are less than 100,000 fold different from other species within the same culture. Theoretically, it can be used in detecting a species in a mixed culture of over 200 species. Currently PCR-MSCC is one of the most economic methods for quantifying single species cell numbers, especially for the low abundant species, in a multiple artificial mixed culture in vitro.

  12. Strategies for enhancing monoclonal antibody accumulation in plant cell and organ cultures.

    Science.gov (United States)

    Sharp, J M; Doran, P M

    2001-01-01

    Various strategies aimed at improving IgG(1) antibody accumulation in transgenic tobacco cell and organ cultures were tested. The form of tissue had a significant effect on antibody levels; shooty teratomas were less productive than hairy roots or suspended cells. Although there were several disadvantages associated with hairy roots compared with suspensions, such as slower growth, slower antibody production, and formation of a greater number of antibody fragments, the roots exhibited superior long-term culture stability. Antibody accumulation in hairy root cultures was improved by increasing the dissolved oxygen tension to 150% air saturation, indicating the need for effective oxygen transfer in root reactors used for antibody production. Preventing N-linked glycosylation using tunicamycin or inhibition of subsequent glycan processing by castanospermine reduced antibody accumulation in the biomass and/or medium in cell suspensions. Loss of antibody from the cultures after its secretion and release into the medium was identified as a major problem. This effect was minimized by inhibiting protein transport in the secretory pathway using Brefeldin A, resulting in antibody accumulation levels up to 2.7 times those in untreated cells. Strategies for protecting secreted antibody, such as addition of poly(vinylpyrrolidone) and periodic harvesting from the medium using hydroxyapatite resin, also increased antibody titers. The mechanisms responsible for the disappearance of antibody from plant culture media were not clearly identified; degradation by proteases and conformational modification of the antibody, such as formation of aggregates, provided an explanation for some but not all the phenomena observed. This work demonstrates that the manipulation and control of culture conditions and metabolic processes in plant tissue cultures can be used to improve the production of foreign proteins. However, loss of secreted antibody from plant culture medium is a significant

  13. PCR-Based Multiple Species Cell Counting for In Vitro Mixed Culture.

    Science.gov (United States)

    Huang, Ruijie; Zhang, Junjie; Yang, X Frank; Gregory, Richard L

    2015-01-01

    Changes of bacterial profiles in microbial communities are strongly associated with human health. There is an increasing need for multiple species research in vitro. To avoid high cost or measurement of a limited number of species, PCR-based multiple species cell counting (PCR-MSCC) has been conceived. Species-specific sequence is defined as a unique sequence of one species in a multiple species mixed culture. This sequence is identified by comparing a random 1000 bp genomic sequence of one species with the whole genome sequences of the other species in the same artificial mixed culture. If absent in the other genomes, it is the species-specific sequence. Species-specific primers were designed based on the species-specific sequences. In the present study, ten different oral bacterial species were mixed and grown in Brain Heart Infusion Yeast Extract with 1% sucrose for 24 hours. Biofilm was harvested and processed for DNA extraction and q-PCR amplification with the species-specific primers. By comparing the q-PCR data of each species in the unknown culture with reference cultures, in which the cell number of each species was determined by colony forming units on agar plate, the cell number of that strain in the unknown mixed culture was calculated. This technique is reliable to count microorganism numbers that are less than 100,000 fold different from other species within the same culture. Theoretically, it can be used in detecting a species in a mixed culture of over 200 species. Currently PCR-MSCC is one of the most economic methods for quantifying single species cell numbers, especially for the low abundant species, in a multiple artificial mixed culture in vitro.

  14. Protection of cultured mammalian cells by rebamipide

    Energy Technology Data Exchange (ETDEWEB)

    Antoku, Shigetoshi; Aramaki, Ryoji [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine; Tanaka, Hisashi; Kusumoto, Naotoshi

    1997-06-01

    Rebamipide which is used as a drug for gastritis and stomach ulcer has large capability for OH radical scavenging. It is expected that rebamipide has protective effect against ionizing radiations. The present paper deals with protective effect of rebamipide for cultured mammalian cells exposed to ionizing radiations. As rebamipide is insoluble in water, three solvents were used to dissolve. Rebamipide dissolved in dimethyl sulfoxide (DMSO), dimethyl formamide (DMFA) and 0.02 N NaOH was added to the cells in Eagle`s minimum essential medium (MEM) supplemented with 10% fetal calf serum and the cells were irradiated with X-rays. After irradiation, the cells were trypsinized, plated in MEM with 10% fetal calf serum and incubated for 7 days in a CO{sub 2} incubator to form colonies. Rebamipide dissolved in 0.02 N NaOH exhibited the protective effect expected its OH radical scavenging capability. However, the protective effect of rebamipide dissolved in DMSO was about half of that expected by its radical scavenging capability and that of rebamipide dissolved in DMFA was not observed. Uptake of rebamipide labeled with {sup 14}C increased with increasing contact time with rebamipide. These rebamipide mainly distributed in nucleus rather than cytoplasm. (author)

  15. Microfluidics and cancer analysis: cell separation, cell/tissue culture, cell mechanics, and integrated analysis systems.

    Science.gov (United States)

    Pappas, Dimitri

    2016-01-21

    Among the growing number of tools available for cancer studies, microfluidic systems have emerged as a promising analytical tool to elucidate cancer cell and tumor function. Microfluidic methods to culture cells have created approaches to provide a range of environments from single-cell analysis to complex three-dimensional devices. In this review we discuss recent advances in tumor cell culture, cancer cell analysis, and advanced studies enabled by microfluidic systems.

  16. Comparison of ex vivo harvested and in vitro cultured materials from Echinococcus granulosus by measuring expression levels of five genes putatively involved in the development and maturation of adult worms.

    Science.gov (United States)

    Dezaki, Ebrahim Saedi; Yaghoubi, Mohammad Mehdi; Spiliotis, Markus; Boubaker, Ghalia; Taheri, Elham; Almani, Pooya Ghaseminejad; Tohidi, Farideh; Harandi, Majid Fasihi; Gottstein, Bruno

    2016-11-01

    Parts of the natural life cycle of Echinococcus granulosus can be retraced in vitro such as the development of protoscoleces into semiadult worms with three or more proglottids, or the redifferentiation of in vitro cultured protoscoleces into metacestode-like cystic structures. Most in vitro generated samples share-at the microscopical level-high similarities with those naturally grown, but developmental differences have also been documented, such as missing egg production in in vitro grown adults or unusual bladder/vesicle formation in protoscoleces cultured into the metacestode direction. The aim of the present study was to explore how far different in vitro generated stage-specific materials/structures match the natural situation on the transcriptome level, based on testing five exemplarily chosen different genes: the frizzled receptor eg-fz4 (posterior marker), the FGF receptor-like factor eg-fgfrl (anterior association), the cell differentiation protein eg-rcd1 (part of the CCR4-NOT complex, a key regulator of eukaryotic gene expression), the rapidly accelerated fibrosarcoma serin/threonin kinase eg-braf (part of the MAPK pathway involved, e.g., in EGF signaling) and the co-smad eg-smadD (downstream factor of TGFβ/BMP2/activin signaling). These genes-tested via qPCR-were selected such as to allow a discussion on their potential role in the development of E. granulosus into the adult stage. Thus, testing took place with three ex vivo isolated samples, namely (i) egg-containing adult worms, (ii) invaginated protoscoleces, and (iii) protoscolex-free germinal layer tissue. Respective data were compared (a) with in vitro generated metacestode-like microcysts developed from protoscolices, and (b) different development stages of protoscoleces in vitro cultured toward adult maturation. As a finding, only eg-smadD and partially eg-fz4 showed high expression similarities between ex vivo harvested and in vitro cultured E. granulosus, thus suggesting a putative role in

  17. Comparison of different options for harvest of a therapeutic protein product from high cell density yeast fermentation broth.

    Science.gov (United States)

    Wang, Alice; Lewus, Rachael; Rathore, Anurag S

    2006-05-05

    Recovery of therapeutic protein from high cell density yeast fermentations at commercial scale is a challenging task. In this study, we investigate and compare three different harvest approaches, namely centrifugation followed by depth filtration, centrifugation followed by filter-aid enhanced depth filtration, and microfiltration. This is achieved by presenting a case study involving recovery of a therapeutic protein from Pichia pastoris fermentation broth. The focus of this study is on performance of the depth filtration and the microfiltration steps. The experimental data has been fitted to the conventional models for cake filtration to evaluate specific cake resistance and cake compressibility. In the case of microfiltration, the experimental data agrees well with flux predicted by shear induced diffusion model. It is shown that, under optimal conditions, all three options can deliver the desired product recovery ( >80%), harvest time ( <15 h including sequential concentration/diafiltration step), and clarification ( <6 NTU). However, the three options differ in terms of process development time required, capital cost, consumable cost, ease of scale-ability and process robustness. It is recommended that these be kept under consideration when making a final decision on a harvesting approach.

  18. System-level modeling and simulation of the cell culture microfluidic biochip ProCell

    DEFF Research Database (Denmark)

    Minhass, Wajid Hassan; Pop, Paul; Madsen, Jan

    2010-01-01

    -defined micro-channels using valves and pumps. We present an approach to the system-level modeling and simulation of a cell culture microfluidic biochip called ProCell, Programmable Cell Culture Chip. ProCell contains a cell culture chamber, which is envisioned to run 256 simultaneous experiments (viewed...

  19. Three-dimensional cell culturing by magnetic levitation.

    Science.gov (United States)

    Haisler, William L; Timm, David M; Gage, Jacob A; Tseng, Hubert; Killian, T C; Souza, Glauco R

    2013-10-01

    Recently, biomedical research has moved toward cell culture in three dimensions to better recapitulate native cellular environments. This protocol describes one method for 3D culture, the magnetic levitation method (MLM), in which cells bind with a magnetic nanoparticle assembly overnight to render them magnetic. When resuspended in medium, an external magnetic field levitates and concentrates cells at the air-liquid interface, where they aggregate to form larger 3D cultures. The resulting cultures are dense, can synthesize extracellular matrix (ECM) and can be analyzed similarly to the other culture systems using techniques such as immunohistochemical analysis (IHC), western blotting and other biochemical assays. This protocol details the MLM and other associated techniques (cell culture, imaging and IHC) adapted for the MLM. The MLM requires 45 min of working time over 2 d to create 3D cultures that can be cultured in the long term (>7 d).

  20. Multiweek cell culture project for use in upper-level biology laboratories.

    Science.gov (United States)

    Marion, Rebecca E; Gardner, Grant E; Parks, Lisa D

    2012-06-01

    This article describes a laboratory protocol for a multiweek project piloted in a new upper-level biology laboratory (BIO 426) using cell culture techniques. Human embryonic kidney-293 cells were used, and several culture media and supplements were identified for students to design their own experiments. Treatments included amino acids, EGF, caffeine, epinephrine, heavy metals, and FBS. Students researched primary literature to determine their experimental variables, made their own solutions, and treated their cells over a period of 2 wk. Before this, a sterile technique laboratory was developed to teach students how to work with the cells and minimize contamination. Students designed their experiments, mixed their solutions, seeded their cells, and treated them with their control and experimental media. Students had the choice of manipulating a number of variables, including incubation times, exposure to treatment media, and temperature. At the end of the experiment, students observed the effects of their treatment, harvested and dyed their cells, counted relative cell numbers in control and treatment flasks, and determined the ratio of living to dead cells using a hemocytometer. At the conclusion of the experiment, students presented their findings in a poster presentation. This laboratory can be expanded or adapted to include additional cell lines and treatments. The ability to design and implement their own experiments has been shown to increase student engagement in the biology-related laboratory activities as well as develop the critical thinking skills needed for independent research.

  1. Primary culture of Rhodnius prolixus (Hemiptera: Reduviidae salivary gland cells

    Directory of Open Access Journals (Sweden)

    Fernanda F Rocha

    2010-03-01

    Full Text Available In the present paper, we developed a primary culture of Rhodnius prolixus salivary gland and main salivary canal cells. Cells remained viable in culture for 30 days. Three types of cells were indentified in the salivary gland cultures, with binuclear cells being the most abundant. The supernatants of salivary cultures contained mainly 16-24 kDa proteins and presented anticoagulant and apyrase activities. Secretion vesicles were observed budding from the cellular monolayer of the main salivary canal cells. These results indicate that R. prolixus salivary proteins may be produced in vitro and suggest that the main salivary canal may have a possible secretory role.

  2. Reducing electrocoagulation harvesting costs for practical microalgal biodiesel production.

    Science.gov (United States)

    Dassey, Adam J; Theegala, Chandra S

    2014-01-01

    Electrocoagulation has shown potential to be a primary microalgae harvesting technique for biodiesel production. However, methods to reduce energy and electrode costs are still necessary for practical application. Electrocoagulation tests were conducted on Nannochloris sp. and Dunaliella sp. using perforated aluminium and iron electrodes under various charge densities. Aluminium electrodes were shown to be more efficient than iron electrodes when harvesting both algal species. Despite the lower harvesting efficiency, however, the iron electrodes were more energy and cost efficient. Operational costs of less than $0.03/L oil were achieved when harvesting Nannochloris sp. with iron electrodes at 35% harvest efficiency, whereas aluminium electrodes cost $0.75/L oil with 42% harvesting efficiency. Increasing the harvesting efficiencies for both aluminium and iron electrodes also increased the overall cost per litre of oil, therefore lower harvesting efficiencies with lower energy inputs was recommended. Also, increasing the culturing salinity to 2 ppt sodium chloride for freshwater Nannochloris sp. was determined practical to improve the electrocoagulation energy efficiency despite a 25% reduction in cell growth.

  3. In vitro expansion and differentiation of rat pancreatic duct-derived stem cells into insulin secreting cells using a dynamicthree-dimensional cell culture system.

    Science.gov (United States)

    Chen, X C; Liu, H; Li, H; Cheng, Y; Yang, L; Liu, Y F

    2016-06-27

    In this study, a dynamic three-dimensional cell culture technology was used to expand and differentiate rat pancreatic duct-derived stem cells (PDSCs) into islet-like cell clusters that can secrete insulin. PDSCs were isolated from rat pancreatic tissues by in situ collagenase digestion and density gradient centrifugation. Using a dynamic three-dimensional culture technique, the cells were expanded and differentiated into functional islet-like cell clusters, which were characterized by morphological and phenotype analyses. After maintaining 1 x 108 isolated rat PDSCs in a dynamic three-dimensional cell culture for 7 days, 1.5 x 109 cells could be harvested. Passaged PDSCs expressed markers of pancreatic endocrine progenitors, including CD29 (86.17%), CD73 (90.73%), CD90 (84.13%), CD105 (78.28%), and Pdx-1. Following 14 additional days of culture in serum-free medium with nicotinamide, keratinocyte growth factor (KGF), and b fibroblast growth factor (FGF), the cells were differentiated into islet-like cell clusters (ICCs). The ICC morphology reflected that of fused cell clusters. During the late stage of differentiation, representative clusters were non-adherent and expressed insulin indicated by dithizone (DTZ)-positive staining. Insulin was detected in the extracellular fluid and cytoplasm of ICCs after 14 days of differentiation. Additionally, insulin levels were significantly higher at this time compared with the levels exhibited by PDSCs before differentiation (P cell culture system, PDSCs can be expanded in vitro and can differentiate into functional islet-like cell clusters.

  4. Modulation of the Culture Supernatant of Decidual Cells with Exogenous Cytokines on Killing Activity of Natural Killer Cells in Early Pregnancy

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To investigate the important function of cytokines in early pregnancy and to provide basic and experimental evidence for understanding the mechanism of their action. Methods Add interferon-γ (IFN-γ) , interleukin- 2(IL- 2) , interleukin- 6(IL-6) and epidermal growth factor (EGF) to the confluent culturing decidual cells with three different concentrations and harvest the culture supernatant after 12, 24 and 48 h separately. Observe the effect of the supernatant on killing activity of NK cells with radioimmunological assay of 51Cr immersion. Results The culture supernatant of decidual cells can promote the killing activity of NK cells in various degrees, and the effect is independent of the type, concentration and acting time of cytokines. Conclusion In normal pregnancy, decidual cytokine network is in a dynamic equilibri um. Exogenous cytokines would be harm to normal pregnancy by interfering the equi librium state, but the exact mechanism needs further study.

  5. Modulation of the Culture Supernatant of Decidual Cells with Exogenous Cytokines on Killing Activity of Natural Killer Cells in Early Pregnancy

    Institute of Scientific and Technical Information of China (English)

    胡冬梅; 王丽莉; 何援利

    2000-01-01

    Objective To investigate the important function of cytohines in early pregnancy and to provide basic and experimental evidence for understanding the mechanism of their action.Methods Add interferon-γ (IFN-γ) ,interleuhin-2(IL-2) , interleuhin-6(IL-6) andepidermal growth factor(EGF) to the confluent culturing decidual cells with three different concentrations and harvest the culture supernatant after 12, 24 and 48 h separately. Observe the effect of the supernatant on killing activity of NK cells with radioimmunological assay of 51Cr immersion.Results The culture supernatant of decidual cells can promote the killing activity of NK cells in various degrees, and the effect is independent of the type, concentration and acting time of cytokines.Conclusion In normal pregnancy, decidual cytokine network is in a dynamic equilibri-um. Exogenous cytokines would be harm to normal pregnancy by interfering the equi-librium state, but the exact mechanism needs further study.

  6. Polydimethylsiloxane SlipChip for mammalian cell culture applications.

    Science.gov (United States)

    Chang, Chia-Wen; Peng, Chien-Chung; Liao, Wei-Hao; Tung, Yi-Chung

    2015-11-07

    This paper reports a polydimethylsiloxane (PDMS) SlipChip for in vitro cell culture applications, multiple-treatment assays, cell co-cultures, and cytokine detection assays. The PDMS SlipChip is composed of two PDMS layers with microfluidic channels on each surface that are separated by a thin silicone fluid (Si-fluid) layer. The integration of Si-fluid enables the two PDMS layers to be slid to different positions; therefore, the channel patterns can be re-arranged for various applications. The SlipChip design significantly reduces the complexity of sample handling, transportation, and treatment processes. To apply the developed SlipChip for cell culture applications, human lung adenocarcinoma epithelial cells (A549) and lung fibroblasts (MRC-5) were cultured to examine the biocompatibility of the developed PDMS SlipChip. Moreover, embryonic pluripotent stem cells (ES-D3) were also cultured in the device to evaluate the retention of their stemness in the device. The experimental results show that cell morphology, viability and proliferation are not affected when the cells are cultured in the SlipChip, indicating that the device is highly compatible with mammalian cell culture. In addition, the stemness of the ES-D3 cells was highly retained after they were cultured in the device, suggesting the feasibility of using the SlipChip for stem cell research. Various cell experiments, such as simultaneous triple staining of cells and co-culture of MRC-5 with A549 cells, were also performed to demonstrate the functionalities of the PDMS SlipChip. Furthermore, we used a cytokine detection assay to evaluate the effect of endotoxin (lipopolysaccharides, LPS) treatment on the cytokine secretion of A549 cells using the SlipChip. The developed PDMS SlipChip provides a straightforward and effective platform for various on-chip in vitro cell cultures and consequent analysis, which is promising for a number of cell biology studies and biomedical applications.

  7. Dissolved oxygen concentration in the medium during cell culture: Defects and improvements.

    Science.gov (United States)

    Zhang, Kuan; Zhao, Tong; Huang, Xin; He, Yunlin; Zhou, Yanzhao; Wu, Liying; Wu, Kuiwu; Fan, Ming; Zhu, Lingling

    2016-03-01

    In vitro cell culture has provided a useful model to study the effects of oxygen on cellular behavior. However, it remains unknown whether the in vitro operations themselves affect the medium oxygen levels and the living states of cells. In addition, a prevailing controversy is whether reactive oxygen species (ROS) production is induced by continuous hypoxia or reoxygenation. In this study, we have measured the effects of different types of cell culture containers and the oxygen environment where medium replacement takes place on the actual oxygen tension in the medium. We found that the deviations of oxygen concentrations in the medium are much greater in 25-cm(2) flasks than in 24-well plates and 35-mm dishes. The dissolved oxygen concentrations in the medium were increased after medium replacement in normoxia, but remained unchanged in glove boxes in which the oxygen tension remained at a low level (11.4, 5.7, and 0.5% O2 ). We also found that medium replacement in normoxia increased the number of ROS-positive cells and reduced the cell viability; meanwhile, medium replacement in a glove box did not produce the above effects. Therefore, we conclude that the use of 25-cm(2) flasks should be avoided and demonstrate that continuous hypoxia does not produce ROS, whereas the reoxygenation that occurs during the harvesting of cells leads to ROS and induces cell death. © 2015 International Federation for Cell Biology.

  8. Synthesis and characterization of porphyrin nanotubes/rods for solar radiation harvesting and solar cells

    Science.gov (United States)

    Mongwaketsi, N.; Khamlich, S.; Klumperman, B.; Sparrow, R.; Maaza, M.

    2012-05-01

    Energy transfer and electron transfer events as they occur between well arranged light harvesting antenna molecules, the reaction center and other factors determine the function of natural photosynthesis. The overall small reorganization energy and the well-balanced electronic coupling between each component bear key characters for the unique efficiency of natural photosynthesis. Such aspects permit the design and assembly of artificial systems that efficiently process solar energy, replicating the natural processes. The rich and extensive transitions seen in porphyrin-based materials hold great expectation as light harvesting building blocks in the construction of molecular architectures, allowing an efficient use of the solar spectrum. Hence in this study porphyrin nanorods are synthesized and characterized for future application in the construction of the artificial light harvesting system. Understanding the sizes and growth mechanism of porphyrins nanorods by self-assembly and molecular recognition is essential for their successful implementation in nanodevices. Spectroscopic and microscopic studies were carried out to investigate the effect that time, concentration and solvents have on the fabrication of porphyrin nanorods by ionic self-assembly of two oppositely charged porphyrins. We investigate in details the heteroaggregate behavior formation of [H4TPPS4]2- and [SnTPyP]2+ mixture by means of the UV-vis spectroscopy and aggregates structure and morphology by transmission electron microscopy (TEM). This study demonstrates the potential for using different concentrations and solvents to influence the physical and optical properties of porphyrin based nanorods.

  9. Synthesis and characterization of porphyrin nanotubes/rods for solar radiation harvesting and solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mongwaketsi, N., E-mail: nanky@tlabs.ac.za [NANOAFNET, MRD-iThemba LABS, National Research Foundation, 1 Old Faure road, Somerset West (South Africa); Stellenbosch University, Chemistry and Polymer Science Department, Private Bag X1, Matieland 7602 (South Africa); CSIR Biosciences, P.O. Box 395, Pretoria 0001 (South Africa); Khamlich, S. [NANOAFNET, MRD-iThemba LABS, National Research Foundation, 1 Old Faure road, Somerset West (South Africa); Faculty of Sciences, Pretoria-Tshwane University of Technology, Private Bag X 680, Pretoria (South Africa); African Laser Centre, CSIR Campus, P.O. Box 395, Pretoria (South Africa); Klumperman, B. [Stellenbosch University, Chemistry and Polymer Science Department, Private Bag X1, Matieland 7602 (South Africa); Sparrow, R. [CSIR Biosciences, P.O. Box 395, Pretoria 0001 (South Africa); Maaza, M., E-mail: maaza@tlabs.ac.za [NANOAFNET, MRD-iThemba LABS, National Research Foundation, 1 Old Faure road, Somerset West (South Africa); Faculty of Sciences, Pretoria-Tshwane University of Technology, Private Bag X 680, Pretoria (South Africa); African Laser Centre, CSIR Campus, P.O. Box 395, Pretoria (South Africa)

    2012-05-15

    Energy transfer and electron transfer events as they occur between well arranged light harvesting antenna molecules, the reaction center and other factors determine the function of natural photosynthesis. The overall small reorganization energy and the well-balanced electronic coupling between each component bear key characters for the unique efficiency of natural photosynthesis. Such aspects permit the design and assembly of artificial systems that efficiently process solar energy, replicating the natural processes. The rich and extensive transitions seen in porphyrin-based materials hold great expectation as light harvesting building blocks in the construction of molecular architectures, allowing an efficient use of the solar spectrum. Hence in this study porphyrin nanorods are synthesized and characterized for future application in the construction of the artificial light harvesting system. Understanding the sizes and growth mechanism of porphyrins nanorods by self-assembly and molecular recognition is essential for their successful implementation in nanodevices. Spectroscopic and microscopic studies were carried out to investigate the effect that time, concentration and solvents have on the fabrication of porphyrin nanorods by ionic self-assembly of two oppositely charged porphyrins. We investigate in details the heteroaggregate behavior formation of [H{sub 4}TPPS{sub 4}]{sup 2-} and [SnTPyP]{sup 2+} mixture by means of the UV-vis spectroscopy and aggregates structure and morphology by transmission electron microscopy (TEM). This study demonstrates the potential for using different concentrations and solvents to influence the physical and optical properties of porphyrin based nanorods.

  10. Quantitative-PCR Assessment of Cryptosporidium parvum Cell Culture Infection

    OpenAIRE

    Di Giovanni, George D.; LeChevallier, Mark W.

    2005-01-01

    A quantitative TaqMan PCR method was developed for assessing the Cryptosporidium parvum infection of in vitro cultivated human ileocecal adenocarcinoma (HCT-8) cell cultures. This method, termed cell culture quantitative sequence detection (CC-QSD), has numerous applications, several of which are presented. CC-QSD was used to investigate parasite infection in cell culture over time, the effects of oocyst treatment on infectivity and infectivity assessment of different C. parvum isolates. CC-Q...

  11. Organ culture-cell culture system for studying multistage carcinogenesis in respiratory epithelium. [Mice

    Energy Technology Data Exchange (ETDEWEB)

    Steele, Vernon E.; Marchok, Ann C.; Nettesheim, Paul

    1977-01-01

    An organ culture-cell culture system was used to demonstrate carcinogen dose-dependent transformation of tracheal epithelial cells in vitro. Tracheal explants were exposed to MNNG (N-methyl-N/sup 1/-nitro-N-nitrosoguanidine) in organ culture. Outgrowths from these explants provided epithelial cell cultures. The numbers of long term epithelial cell cultures and cell lines that were established per explant increased as MNNG exposure concentration increased. At the present time, more cell lines derived from explants exposed to the highest MNNG concentration have produced palpable tumors than cell lines derived from explants exposed to lower MNNG concentrations. No cell lines were established from primaries derived from control explants. TPA (12-0-tetradecanoyl-phorbol-13-acetate), stimulates DNA synthesis in tracheal epithelium in organ culture in a manner simular to that described for mouse skin. Short exposures to TPA not only stimulated DNA synthesis earlier, but the stimulation was greater than that obtained with continuous exposure. At the present time, exposure of tracheal organ cultures to MNNG followed by TPA has resulted in an enhanced production of morphologically altered cells in primary epithelial cell cultures, than exposure to either agent alone.

  12. Dose responses for Colletotrichum lindemuthianum elicitor-mediated enzyme induction in French bean cell suspension cultures.

    Science.gov (United States)

    Dixon, R A; Dey, P M; Murphy, D L; Whitehead, I M

    1981-03-01

    The induction of L-phenylalanine ammonialyase (PAL, EC 4.3.1.5) and flavanone synthase in French bean cell suspension cultures in response to heat-released elicitor from cell walls of the phytopathogenic fungus Colletotrichum lindemuthianum is highly dependent upon elicitor concentration. The elicitor dose-response curve for PAL induction shows two maxima at around 17.5 and 50 μg elicitor carbohydrate per ml culture, whereas the flavanone synthase response shows one maximum at around 100 μg ml(-1). The PAL response is independent of the elicitor concentration present during the lag phase of enzyme induction; if the initial elicitor concentration is increased after 2 h by addition of extra elicitor, or decreased by dilution of the cultures, the dose response curves obtained reflect the concentration of elicitor present at the time of harvest. PAL induction is not prevented by addition of methyl sugar derivatives to the cultures; α-methyl-D-glucoside, itself a weak elicitor of PAL activity, elicits a multiphasic PAL response when increasing concentrations are added in the presence of Colletotrichum elicitor. Eight fractions with different monosaccharide compositions, obtained from the crude elicitor by gel-filtration, each elicit different dose-responses for PAL induction; the response to unfractionated elicitor is not the sum of the response to the isolated fractions. There is no correlation between the ability of the fractions to induce PAL in the cultures and their ability to act as elicitors of isoflavonoid phytoalexin accumulation in bean hypocotyls.

  13. Increased production of recombinant prourokinase with porous microcarrier cell culture by periodic pressure oscillation in a stirred tank reactor

    Institute of Scientific and Technical Information of China (English)

    Hu Xianwen; Gao Lihua; Li Zuohu; Xiao Chengzu; Xu Zhaoping

    2006-01-01

    An rCHO cell line expressing recombinant human prourokinase (pro-UK at the level of 5μg/106cells/d was cultivated on Cytopore cellulose porous microcarriers in a 7.5L Biostat CT stirred tank reactor. A periodic pressure oscillation of 0.04 MPa and 0.04 Hz was adopted to introduce a physical stimulus on the rCHO cells and to improve mass transfer characteristic between cells and medium in the process of porous microcarrier CHO cell culture. Compared to constant pressure culture, the oscillation culture didn't influence specific cell growth rate significantly, but could enhance the pro-UK specific production by 10%~40%, and reduce production of lactate by 10%~30%. In the perfusion culture of recombinant CHO cell with serum-free medium for 67 days, cell density could reach 2.64×107/ml, the maximal prourokinase concentration in harvested supernatant was about 118mg/L, a total of 21.1 grams of prourokinase was produced in 313 liters of supernatant. In conclusion, the perfusion cell culture with periodic pressure oscillation can enhance the production of recombinant protein and increase the reactor specific productivity.

  14. Growth of the Pittsburgh Pneumonia Agent in Animal Cell Cultures

    OpenAIRE

    Rinaldo, Charles R.; Pasculle, A. William; Myerowitz, Richard L.; Gress, Francis M.; Dowling, John N.

    1981-01-01

    Pittsburgh pneumonia agent (Legionella micdadei) grew in monkey, chicken, and human cell cultures. Pittsburgh pneumonia agent grew predominantly in the cytoplasm, resulting in a nonfocal, mild cytopathic effect.

  15. Particle Trajectories in Rotating Wall Cell Culture Devices

    Science.gov (United States)

    Ramachandran N.; Downey, J. P.

    1999-01-01

    Cell cultures are extremely important to the medical community since such cultures provide an opportunity to perform research on human tissue without the concerns inherent in experiments on individual humans. Development of cells in cultures has been found to be greatly influenced by the conditions of the culture. Much work has focused on the effect of the motions of cells in the culture relative to the solution. Recently rotating wall vessels have been used with success in achieving improved cellular cultures. Speculation and limited research have focused on the low shear environment and the ability of rotating vessels to keep cells suspended in solution rather than floating or sedimenting as the primary reasons for the improved cellular cultures using these devices. It is widely believed that the cultures obtained using a rotating wall vessel simulates to some degree the effect of microgravity on cultures. It has also been speculated that the microgravity environment may provide the ideal acceleration environment for culturing of cellular tissues due to the nearly negligible levels of sedimentation and shear possible. This work predicts particle trajectories of cells in rotating wall vessels of cylindrical and annular design consistent with the estimated properties of typical cellular cultures. Estimates of the shear encountered by cells in solution and the interactions with walls are studied. Comparisons of potential experiments in ground and microgravity environments are performed.

  16. Cell culture chip using low-shear mass transport.

    Science.gov (United States)

    Liu, Ke; Pitchimani, Rajasekar; Dang, Dana; Bayer, Keith; Harrington, Tyler; Pappas, Dimitri

    2008-06-03

    We have developed a flow cell that allows culturing adherent cells as well as suspended cells in a stable, homogeneous, and low-shear force environment. The device features continuous medium supply and waste exchange. In this paper, a simple and fast protocol for device design, fabrication, and assembly (sealing) based on a poly(dimethylsiloxane) (PMDS)/glass slide hybrid structure is described. The cell culture system performance was monitored, and the effective shear force inside the culture well was also determined. By manipulating the device dimensions and volumetric flow rate, shear stress was controlled during experiments. Cell adhesion, growth, proliferation, and death over long-term culture periods were observed by microscopy. The growth of both endothelial and suspension cells in this device exhibited comparable characteristics to those of traditional approaches. The low-shear culture device significantly reduced shear stress encountered in microfluidic systems, allowing both adherent and suspended cells to be grown in a simple device.

  17. Three-dimensional Tissue Culture Based on Magnetic Cell Levitation

    Science.gov (United States)

    Souza, Glauco R.; Molina, Jennifer R.; Raphael, Robert M.; Ozawa, Michael G.; Stark, Daniel J.; Levin, Carly S.; Bronk, Lawrence F.; Ananta, Jeyarama S.; Mandelin, Jami; Georgescu, Maria-Magdalena; Bankson, James A.; Gelovani, Juri G.

    2015-01-01

    Cell culture is an essential tool for drug discovery, tissue engineering, and stem cell research. Conventional tissue culture produces two-dimensional (2D) cell growth with gene expression, signaling, and morphology that can differ from those in vivo and thus compromise clinical relevancy1–5. Here we report a three-dimensional (3D) culture of cells based on magnetic levitation in the presence of hydrogels containing gold and magnetic iron oxide (MIO) nanoparticles plus filamentous bacteriophage. This methodology allows for control of cell mass geometry and guided, multicellular clustering of different cell types in co-culture through spatial variance of the magnetic field. Moreover, magnetic levitation of human glioblastoma cells demonstrates similar protein expression profiles to those observed in human tumor xenografts. Taken together, these results suggest levitated 3D culture with magnetized phage-based hydrogels more closely recapitulates in vivo protein expression and allows for long-term multi-cellular studies. PMID:20228788

  18. HAIR CELL-LIKE CELL GENERATION INDUCED BY NATURE CULTURE OF ADULT RAT AUDITORY EPITHELIUM

    Institute of Scientific and Technical Information of China (English)

    Liu Hui; Zhu Hongliang; Li Shengli; Yao Xiaobao; Wang Xiaoxia

    2006-01-01

    Objective To establish adult rat auditory epithelial cell culture and try to find precursor cells of auditory hair cells in vitro. Methods With refinement of culture media and techniques, cochlear sensory epithelial cells of adult rat were cultured. Immunocytochemistry and Bromodeoxyuridine (BrdU)labeling were used to detect properties and mitotic status of cultured cells. Results The cultured auditory epithelial cells showed a large, flat epithelial morphotype and expressed F-actin and cytokeratin, a subset of cells generated from auditory epithelium were labeled by calretinin, a specific marker of early hair cell. Conclusion Adult rat auditory epithelium can be induced to generate hair cell-like cells by nature culture, this phenomenon suggests that progenitor cells may exist in rat cochlea and they may give birth to new hair cells. Whether these progenitor cells are tissue specific stem cells is still need more study.

  19. Dissociated neurons of the pupal blowfly antenna in cell culture.

    Science.gov (United States)

    Nakagawa, A; Iwama, A

    1995-12-01

    Primary cell cultures are useful for studying the function of neurons in a simplified and controlled environment. We established a primary culture of antennal cells from pupal blowflies in order to investigate olfactory receptor neurons. In cultures, neuron-like cells were identified on the basis of morphology and immunocytochemical characterization with anti-HRP staining. Neuron-like cells showed variety in the extension pattern of neurites. Many neuron-like cells extended a single prominent long process, which reached about 200 microm after four days, and several short ones. However, some neuron-like cells differentiated in other ways; some exhibited bipolar or multipolar processes, distinct from intact olfactory receptor neurons. The size of cell bodies of neuron-like cells as divisible into two groups; approx. 7 microm diameter and 10-15 microm diameter. Neuron-like cells in culture will provide a good model for electrophysiological analysis and for developmental studies of olfactory receptor neurons.

  20. Usability and Applicability of Microfluidic Cell Culture Systems

    DEFF Research Database (Denmark)

    Hemmingsen, Mette

    Microfluidic cell culture has been a research area with great attention the last decade due to its potential to mimic the in vivo cellular environment more closely compared to what is possible by conventional cell culture methods. Many exciting and complex devices have been presented providing...... possibilities for, for example, precise control of the chemical environment, 3D cultures, controlled co-culture of different cell types or automated, individual control of up to 96 cell culture chambers in one integrated system. Despite the great new opportunities to perform novel experimental designs......, these devices still lack general implementation into biological research laboratories. In this project, the usability and applicability of microfluidic cell culture systems have been investigated. The tested systems display good properties regarding optics and compatibility with standard laboratory equipment...

  1. THE ALKALOID CYTISINE IN THE CELL CULTURE

    Directory of Open Access Journals (Sweden)

    Gazaliev A.M.

    2012-08-01

    Full Text Available Alkaloids are vegetative establishments of complex and original structure with nitrous heterocycles in the basis. For a long time they drew researchers’ attention because of their unique and specific physiological effect on alive organisms. Not all the representatives of the globe’s flora contain these unique substances. Alkaloid cytisine is to be found mainly in the plants of the fabaceous family - Fabaceae. For the cytisine production the seeds of Thermopsis lanceolata R.Br (T. lanceolata R.Br and Cytisus laburnum (C. laburnum are used as a raw material. The object of the research is T. lanceolata cell culture. Sterile sprouts are used at the first stage of the experiment. Callus genesis is accompanied with dedifferentiation. It leads to the cellular organization simplification. Based on an important property of a plant cell, such as totipotency, there appears the formation of the “de novo” biosynthetic device. The cultivation algorithm consists of two basic stages: (i the cultivation conditions optimization of callus with a high level of the primary metabolites biosynthesis (Aspartat – lysine; (ii the research of cultivation chemical and physical factors influence on the secondary metabolite (cytisine biosynthesis and accumulation. During the cultivation the Murashige and Skoog classical recipe of nutrient medium will be used. Optimization of the cultivation conditions will concern the phytohormones, macro- and micronutrients content, as the purpose of optimization is the production of the determined high-level competence embriogenical callus. The main problem is genetic heterogeneity of a cellular population and instability of morpho-physiological processes. The correct management of higher plants cells population is possible at the synchronization of a cellular cycle phases. The references analysis has shown that it is almost impossible to synchronize cellular cycles in the culture of plant tissue. The application of chemical

  2. Celebrating Harvest

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    In rural customs, recreational activities are Festival when northern farmers are thankful for Celebrating Harvest depicts a traditional act northwestern Shaanxi Province living on the L(?) is an animated painting with strong local flavor

  3. Bumper Harvest

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A large summer grain crop is helping to ease food security concerhs in China,despite rising global prices Five consecutive years of bumper grain harvests, including an abundant yield this summer, have enabled

  4. An Optically Controlled 3D Cell Culturing System

    Directory of Open Access Journals (Sweden)

    Kelly S. Ishii

    2011-01-01

    Full Text Available A novel 3D cell culture system was developed and tested. The cell culture device consists of a microfluidic chamber on an optically absorbing substrate. Cells are suspended in a thermoresponsive hydrogel solution, and optical patterns are utilized to heat the solution, producing localized hydrogel formation around cells of interest. The hydrogel traps only the desired cells in place while also serving as a biocompatible scaffold for supporting the cultivation of cells in 3D. This is demonstrated with the trapping of MDCK II and HeLa cells. The light intensity from the optically induced hydrogel formation does not significantly affect cell viability.

  5. Aeroponics for the culture of organisms, tissues and cells.

    Science.gov (United States)

    Weathers, P J; Zobel, R W

    1992-01-01

    Characteristics of aeroponics are discussed. Contrast is made, where appropriate, with hydroponics and aero-hydroponics as applies to research and commercial applications of nutrient mist technology. Topics include whole plants, plant tissue cultures, cell and microbial cultures, and animal tissue cultures with regard to operational considerations (moisture, temperature, minerals, gaseous atmosphere) and design of apparati.

  6. Systems Biology for Organotypic Cell Cultures

    Energy Technology Data Exchange (ETDEWEB)

    Grego, Sonia [RTI International, Research Triangle Park, NC (United States); Dougherty, Edward R. [Texas A & M Univ., College Station, TX (United States); Alexander, Francis J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Auerbach, Scott S. [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Berridge, Brian R. [GlaxoSmithKline, Research Triangle Park, NC (United States); Bittner, Michael L. [Translational Genomics Research Inst., Phoenix, AZ (United States); Casey, Warren [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Cooley, Philip C. [RTI International, Research Triangle Park, NC (United States); Dash, Ajit [HemoShear Therapeutics, Charlottesville, VA (United States); Ferguson, Stephen S. [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Fennell, Timothy R. [RTI International, Research Triangle Park, NC (United States); Hawkins, Brian T. [RTI International, Research Triangle Park, NC (United States); Hickey, Anthony J. [RTI International, Research Triangle Park, NC (United States); Kleensang, Andre [Johns Hopkins Univ., Baltimore, MD (United States). Center for Alternatives to Animal Testing; Liebman, Michael N. [IPQ Analytics, Kennett Square, PA (United States); Martin, Florian [Phillip Morris International, Neuchatel (Switzerland); Maull, Elizabeth A. [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Paragas, Jason [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Qiao, Guilin [Defense Threat Reduction Agency, Ft. Belvoir, VA (United States); Ramaiahgari, Sreenivasa [National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States); Sumner, Susan J. [RTI International, Research Triangle Park, NC (United States); Yoon, Miyoung [The Hamner Inst. for Health Sciences, Research Triangle Park, NC (United States); ScitoVation, Research Triangle Park, NC (United States)

    2016-08-04

    Translating in vitro biological data into actionable information related to human health holds the potential to improve disease treatment and risk assessment of chemical exposures. While genomics has identified regulatory pathways at the cellular level, translation to the organism level requires a multiscale approach accounting for intra-cellular regulation, inter-cellular interaction, and tissue/organ-level effects. Tissue-level effects can now be probed in vitro thanks to recently developed systems of three-dimensional (3D), multicellular, “organotypic” cell cultures, which mimic functional responses of living tissue. However, there remains a knowledge gap regarding interactions across different biological scales, complicating accurate prediction of health outcomes from molecular/genomic data and tissue responses. Systems biology aims at mathematical modeling of complex, non-linear biological systems. We propose to apply a systems biology approach to achieve a computational representation of tissue-level physiological responses by integrating empirical data derived from organotypic culture systems with computational models of intracellular pathways to better predict human responses. Successful implementation of this integrated approach will provide a powerful tool for faster, more accurate and cost-effective screening of potential toxicants and therapeutics. On September 11, 2015, an interdisciplinary group of scientists, engineers, and clinicians gathered for a workshop in Research Triangle Park, North Carolina, to discuss this ambitious goal. Participants represented laboratory-based and computational modeling approaches to pharmacology and toxicology, as well as the pharmaceutical industry, government, non-profits, and academia. Discussions focused on identifying critical system perturbations to model, the computational tools required, and the experimental approaches best suited to generating key data. This consensus report summarizes the discussions held.

  7. Embryonic stem cells in scaffold-free three-dimensional cell culture: osteogenic differentiation and bone generation

    Directory of Open Access Journals (Sweden)

    Meyer Ulrich

    2011-07-01

    Full Text Available Abstract Extracorporeal formation of mineralized bone-like tissue is still an unsolved challenge in tissue engineering. Embryonic stem cells may open up new therapeutic options for the future and should be an interesting model for the analysis of fetal organogenesis. Here we describe a technique for culturing embryonic stem cells (ESCs in the absence of artificial scaffolds which generated mineralized miromasses. Embryonic stem cells were harvested and osteogenic differentiation was stimulated by the addition of dexamethasone, ascorbic acid, and ß-glycerolphosphate (DAG. After three days of cultivation microspheres were formed. These spherical three-dimensional cell units showed a peripheral zone consisting of densely packed cell layers surrounded by minerals that were embedded in the extracellular matrix. Alizarine red staining confirmed evidence of mineralization after 10 days of DAG stimulation in the stimulated but not in the control group. Transmission electron microscopy demonstrated scorching crystallites and collagenous fibrils as early indication of bone formation. These extracellular structures resembled hydroxyl apatite-like crystals as demonstrated by distinct diffraction patterns using electron diffraction analysis. The micromass culture technique is an appropriate model to form three-dimensional bone-like micro-units without the need for an underlying scaffold. Further studies will have to show whether the technique is applicable also to pluripotent stem cells of different origin.

  8. Isolation and culture of larval cells from C. elegans.

    Directory of Open Access Journals (Sweden)

    Sihui Zhang

    Full Text Available Cell culture is an essential tool to study cell function. In C. elegans the ability to isolate and culture cells has been limited to embryonically derived cells. However, cells or blastomeres isolated from mixed stage embryos terminally differentiate within 24 hours of culture, thus precluding post-embryonic stage cell culture. We have developed an efficient and technically simple method for large-scale isolation and primary culture of larval-stage cells. We have optimized the treatment to maximize cell number and minimize cell death for each of the four larval stages. We obtained up to 7.8×10(4 cells per microliter of packed larvae, and up to 97% of adherent cells isolated by this method were viable for at least 16 hours. Cultured larval cells showed stage-specific increases in both cell size and multinuclearity and expressed lineage- and cell type-specific reporters. The majority (81% of larval cells isolated by our method were muscle cells that exhibited stage-specific phenotypes. L1 muscle cells developed 1 to 2 wide cytoplasmic processes, while L4 muscle cells developed 4 to 14 processes of various thicknesses. L4 muscle cells developed bands of myosin heavy chain A thick filaments at the cell center and spontaneously contracted ex vivo. Neurons constituted less than 10% of the isolated cells and the majority of neurons developed one or more long, microtubule-rich protrusions that terminated in actin-rich growth cones. In addition to cells such as muscle and neuron that are high abundance in vivo, we were also able to isolate M-lineage cells that constitute less than 0.2% of cells in vivo. Our novel method of cell isolation extends C. elegans cell culture to larval developmental stages, and allows use of the wealth of cell culture tools, such as cell sorting, electrophysiology, co-culture, and high-resolution imaging of subcellular dynamics, in investigation of post-embryonic development and physiology.

  9. Using Tissue Culture To Investigate Plant Cell Differentiation and Dedifferentiation.

    Science.gov (United States)

    Bozzone, Donna M.

    1997-01-01

    Describes an experimental project that uses plant tissue culture techniques to examine cell differentiation in the carrot. Allows students to gain experience in some important techniques and to explore fundamental questions about cell differentiation. (DDR)

  10. Using Tissue Culture To Investigate Plant Cell Differentiation and Dedifferentiation.

    Science.gov (United States)

    Bozzone, Donna M.

    1997-01-01

    Describes an experimental project that uses plant tissue culture techniques to examine cell differentiation in the carrot. Allows students to gain experience in some important techniques and to explore fundamental questions about cell differentiation. (DDR)

  11. Acetylsalicylic acid induces programmed cell death in Arabidopsis cell cultures.

    Science.gov (United States)

    García-Heredia, José M; Hervás, Manuel; De la Rosa, Miguel A; Navarro, José A

    2008-06-01

    Acetylsalicylic acid (ASA), a derivative from the plant hormone salicylic acid (SA), is a commonly used drug that has a dual role in animal organisms as an anti-inflammatory and anticancer agent. It acts as an inhibitor of cyclooxygenases (COXs), which catalyze prostaglandins production. It is known that ASA serves as an apoptotic agent on cancer cells through the inhibition of the COX-2 enzyme. Here, we provide evidences that ASA also behaves as an agent inducing programmed cell death (PCD) in cell cultures of the model plant Arabidopsis thaliana, in a similar way than the well-established PCD-inducing agent H(2)O(2), although the induction of PCD by ASA requires much lower inducer concentrations. Moreover, ASA is herein shown to be a more efficient PCD-inducing agent than salicylic acid. ASA treatment of Arabidopsis cells induces typical PCD-linked morphological and biochemical changes, namely cell shrinkage, nuclear DNA degradation, loss of mitochondrial membrane potential, cytochrome c release from mitochondria and induction of caspase-like activity. However, the ASA effect can be partially reverted by jasmonic acid. Taking together, these results reveal the existence of common features in ASA-induced animal apoptosis and plant PCD, and also suggest that there are similarities between the pathways of synthesis and function of prostanoid-like lipid mediators in animal and plant organisms.

  12. Surface design of antibody-immobilized thermoresponsive cell culture dishes for recovering intact cells by low-temperature treatment.

    Science.gov (United States)

    Kobayashi, Jun; Hayashi, Masaki; Ohno, Takahiro; Nishi, Masanori; Arisaka, Yoshinori; Matsubara, Yoshinori; Kakidachi, Hiroshi; Akiyama, Yoshikatsu; Yamato, Masayuki; Horii, Akihiro; Okano, Teruo

    2014-11-01

    Antibody-immobilized thermoresponsive poly(N-isopropylacrylamide-co-2-carboxyisopropylacrylamide) [poly(IPAAm-co-CIPAAm)]-grafted cell culture surfaces were designed to enhance both the initial adhesion of weakly adhering cells and the ability of cells to detach in response to low temperature through the regulation of affinity binding between immobilized antibodies and antigens on the cellular surface. Ty-82 cells and neonatal normal human dermal fibroblasts (NHDFs), which express CD90 on the cell surface, adhered to anti-CD90 antibody-immobilized thermoresponsive surfaces at 37°C, a condition at which the grafted thermoresponsive polymer chains shrank. Adherent Ty-82 cells were detached from the surfaces by lowering the temperature to 20°C and applying external forces, such as pipetting, whereas cultured NHDF sheets spontaneously detached themselves from the surface in response to reduced temperature alone. When the temperature was decreased to 20°C, the swelling of grafted thermoresponsive polymer chains weakened the affinity binding between immobilized antibody and antigen on the cells due to the increasing steric hindrance of the polymer chains around the antigen-recognition site of the immobilized antibodies. No contamination was detected on cells harvested from covalently immobilized antibodies on the culture surfaces by low-temperature treatment, whereas a carryover of the antibody and avidin from the avidin-biotin binding surface was observed. Furthermore, the initial adhesion of adipose tissue-derived cells, which adhere weakly to PIPAAm-grafted surfaces, was enhanced on the antibody-immobilized thermoresponsive surfaces.

  13. Culturing and applications of rotating wall vessel bioreactor derived 3D epithelial cell models.

    Science.gov (United States)

    Radtke, Andrea L; Herbst-Kralovetz, Melissa M

    2012-04-03

    . The progression from a monolayer of epithelial cells to a fully differentiated 3-D aggregate varies based on cell type(1, 7-13). Periodic sampling from the bioreactor allows for monitoring of epithelial aggregate formation, cellular differentiation markers and viability (Figure 1D). Once cellular differentiation and aggregate formation is established, the cells are harvested from the bioreactor, and similar assays performed on 2-D cells can be applied to the 3-D aggregates with a few considerations (Figure 1E-G). In this work, we describe detailed steps of how to culture 3-D epithelial cell aggregates in the RWV bioreactor system and a variety of potential assays and analyses that can be executed with the 3-D aggregates. These analyses include, but are not limited to, structural/morphological analysis (confocal, scanning and transmission electron microscopy), cytokine/chemokine secretion and cell signaling (cytometric bead array and Western blot analysis), gene expression analysis (real-time PCR), toxicological/drug analysis and host-pathogen interactions. The utilization of these assays set the foundation for more in-depth and expansive studies such as metabolomics, transcriptomics, proteomics and other array-based applications. Our goal is to present a non-conventional means of culturing human epithelial cells to produce organotypic 3-D models that recapitulate the human in vivo tissue, in a facile and robust system to be used by researchers with diverse scientific interests.

  14. Efficient light harvesting by photon downconversion and light trapping in hybrid ZnS nanoparticles/Si nanotips solar cells.

    Science.gov (United States)

    Huang, Chun-Ying; Wang, Di-Yan; Wang, Chun-Hsiung; Chen, Yung-Ting; Wang, Yaw-Tyng; Jiang, You-Ting; Yang, Ying-Jay; Chen, Chia-Chun; Chen, Yang-Fang

    2010-10-26

    A hybrid colloidal ZnS nanoparticles/Si nanotips p-n active layer has been demonstrated to have promising potential for efficient solar spectrum utilization in crystalline silicon-based solar cells. The hybrid solar cell shows an enhancement of 20% in the short-circuit current and approximately 10% in power conversion efficiency compared to its counterpart without integrating ZnS nanoparticles. The enhancement has been investigated by external quantum efficiency, photoluminescence excitation spectrum, photoluminescence, and reflectance to distinct the role of ZnS quantum dots for light harvesting. It is concluded that ZnS nanoparticles not only act as frequency downconversion centers in the ultraviolet region but also serve as antireflection coating for light trapping in the measured spectral regime. Our approach is ready to be extended to many other material systems for the creation of highly efficient photovoltaic devices.

  15. A 3D cell culture system: separation distance between INS-1 cell and endothelial cell monolayers co-cultured in fibrin influences INS-1 cells insulin secretion.

    Science.gov (United States)

    Sabra, Georges; Vermette, Patrick

    2013-02-01

    The aim of this study was to develop an in vitro cell culture system allowing studying the effect of separation distance between monolayers of rat insulinoma cells (INS-1) and human umbilical vein endothelial cells (HUVEC) co-cultured in fibrin over INS-1 cell insulin secretion. For this purpose, a three-dimensional (3D) cell culture chamber was designed, built using micro-fabrication techniques and validated. The co-culture was successfully carried out and the effect on INS-1 cell insulin secretion was investigated. After 48 and 72 h, INS-1 cells co-cultured with HUVEC separated by a distance of 100 µm revealed enhanced insulin secretion compared to INS-1 cells cultured alone or co-cultured with HUVEC monolayers separated by a distance of 200 µm. These results illustrate the importance of the separation distance between two cell niches for cell culture design and the possibility to further enhance the endocrine function of beta cells when this factor is considered.

  16. Post-thaw non-cultured and post-thaw cultured equine cord blood mesenchymal stromal cells equally suppress lymphocyte proliferation in vitro.

    Directory of Open Access Journals (Sweden)

    Lynn B Williams

    Full Text Available Multipotent mesenchymal stromal cells (MSC are receiving increased attention for their non-progenitor immunomodulatory potential. Cryopreservation is commonly used for long-term storage of MSC. Post-thaw MSC proliferation is associated with a lag-phase in vitro. How this lag-phase affect MSC immunomodulatory properties is unknown. We hypothesized that in vitro there is no difference in lymphocyte suppression potential between quick-thawed cryopreserved equine cord blood (CB MSC immediately included in mixed lymphocyte reaction (MLR and same MSC allowed post-thaw culture time prior to inclusion in MLR. Cryopreserved CB-MSC from five unrelated foals were compared using two-way MLR. For each of the five unrelated MSC cultures, paired MLR assays of MSC allowed five days of post-thaw culture and MSC included in MLR assay immediately post-thawing were evaluated. We report no difference in the suppression of lymphocyte proliferation by CB-MSC that had undergone post-thaw culture and MSC not cultured post-thaw (p<0.0001. Also, there was no inter-donor variability between the lymphocyte suppressive properties of MSC harvested from the five different donors (p = 0.13. These findings suggest that cryopreserved CB-MSC may have clinical utility immediately upon thawing. One implication hereof is the possibility of using cryopreserved CB-MSC at third party locations without the need for cell culture equipment or competencies.

  17. Callus production from photoautotrophic soybean cell culture protoplasts.

    Science.gov (United States)

    Chowhury, V K; Widholm, J M

    1985-10-01

    Protoplasts were prepared from a photoautotrophic (PA) cell line of Glycine max (soybean). A yield of 75 to 90% after two to three hours digestion in a mixture of 1% Cellulase R10, 0.2% Pectolyase Y23 and 2% Driselase was obtained. Cell division and colony formation occurred from approximately 18% of the plated protoplasts. The cultured protoplasts were as sensitive to the herbicide atrazine, a photosynthetic inhibitor, as the original PA cells under the same conditions. Protoplasts and cells of a heterotrophic (HT) soybean culture were not as sensitive to atrazine. The isolated protoplasts retained the PA characteristics of the parental culture in the callus and cell suspension cultures obtained from the protoplasts. The chromosome numbers in the parental cell line and in cells derived from the isolated protoplasts (both PA and HT) were found to be largely (99%) the normal diploid number of 40.

  18. HEPES inhibits the conversion of prion protein in cell culture.

    Science.gov (United States)

    Delmouly, Karine; Belondrade, Maxime; Casanova, Danielle; Milhavet, Ollivier; Lehmann, Sylvain

    2011-05-01

    HEPES is a well-known buffering reagent used in cell-culture medium. Interestingly, this compound is also responsible for significant modifications of biological parameters such as uptake of organic molecules, alteration of oxidative stress mechanisms or inhibition of ion channels. While using cell-culture medium supplemented with HEPES on prion-infected cells, it was noticed that there was a significant concentration-dependent inhibition of accumulation of the abnormal isoform of the prion protein (PrP(Sc)). This effect was present only in live cells and was thought to be related to modification of the PrP environment or biology. These results could modify the interpretation of cell-culture assays of prion therapeutic agents, as well as of previous cell biology results obtained in the field using HEPES buffers. This inhibitory effect of HEPES could also be exploited to prevent contamination or propagation of prions in cell culture.

  19. Horizontally rotated cell culture system with a coaxial tubular oxygenator

    Science.gov (United States)

    Wolf, David A. (Inventor); Schwarz, Ray P. (Inventor); Trinh, Tinh T. (Inventor)

    1991-01-01

    The present invention relates to a horizontally rotating bioreactor useful for carrying out cell and tissue culture. For processing of mammalian cells, the system is sterilized and fresh fluid medium, microcarrier beads, and cells are admitted to completely fill the cell culture vessel. An oxygen containing gas is admitted to the interior of the permeable membrane which prevents air bubbles from being introduced into the medium. The cylinder is rotated at a low speed within an incubator so that the circular motion of the fluid medium uniformly suspends the microbeads throughout the cylinder during the cell growth period. The unique design of this cell and tissue culture device was initially driven by two requirements imposed by its intended use for feasibility studies for three dimensional culture of living cells and tissues in space by JSC. They were compatible with microgravity and simulation of microgravity in one G. The vessels are designed to approximate the extremely quiescent low shear environment obtainable in space.

  20. 21 CFR 876.5885 - Tissue culture media for human ex vivo tissue and cell culture processing applications.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tissue culture media for human ex vivo tissue and... DEVICES Therapeutic Devices § 876.5885 Tissue culture media for human ex vivo tissue and cell culture processing applications. (a) Identification. Tissue culture media for human ex vivo tissue and cell culture...

  1. Single-cell qPCR on dispersed primary pituitary cells -an optimized protocol

    Directory of Open Access Journals (Sweden)

    Haug Trude M

    2010-11-01

    Full Text Available Abstract Background The incidence of false positives is a potential problem in single-cell PCR experiments. This paper describes an optimized protocol for single-cell qPCR measurements in primary pituitary cell cultures following patch-clamp recordings. Two different cell harvesting methods were assessed using both the GH4 prolactin producing cell line from rat, and primary cell culture from fish pituitaries. Results Harvesting whole cells followed by cell lysis and qPCR performed satisfactory on the GH4 cell line. However, harvesting of whole cells from primary pituitary cultures regularly produced false positives, probably due to RNA leakage from cells ruptured during the dispersion of the pituitary cells. To reduce RNA contamination affecting the results, we optimized the conditions by harvesting only the cytosol through a patch pipette, subsequent to electrophysiological experiments. Two important factors proved crucial for reliable harvesting. First, silanizing the patch pipette glass prevented foreign extracellular RNA from attaching to charged residues on the glass surface. Second, substituting the commonly used perforating antibiotic amphotericin B with β-escin allowed efficient cytosol harvest without loosing the giga seal. Importantly, the two harvesting protocols revealed no difference in RNA isolation efficiency. Conclusion Depending on the cell type and preparation, validation of the harvesting technique is extremely important as contaminations may give false positives. Here we present an optimized protocol allowing secure harvesting of RNA from single cells in primary pituitary cell culture following perforated whole cell patch clamp experiments.

  2. Flow cytometric analysis of hemetopoietic progenitor cells in peripheral blood stem cell harvest from patients with CD34 positive acute leukemia.

    Science.gov (United States)

    Miyazaki, T; Matsuda, I; Oguri, M; Amaya, H; Kiyosaki, M; Hamada, A; Tamaki, S; Tashiro, E; Kudo, Y; Taniguchi, O; Nakamura, T; Tomoyasu, S

    2001-01-01

    We analyzed CD34 positive cells in peripheral blood stem cell harvest (PBSCH) using flow cytometry. PBSCH from CD34 positive acute myelogeous leukemia (AML-M2) patient contained 1.87% CD34 positive cells, of which 1.21% was represented by MRD.PBSCH from CD34 positive acute lymphoblast leukemia (ALL) patient contained 3.14% CD34 positive cells, of which 0.11% was accounted for by minimal residual disease (MRD). If PBSCH from CD34 positive acute leukemia patient is analyzed for CD34 monoclonal antibody alone, the presence of CD34 positive MRD may escape attention so that CD34 positive hematopoietic progenitor cells may be overestimated. To avoid this risk, it is necessary to analyze PBSCH using both CD34 monoclonal antibody and characteristic markers of leukemia cells that were found pre-treatment.

  3. Gene markers of cellular aging in human multipotent stromal cells in culture.

    Science.gov (United States)

    Bellayr, Ian H; Catalano, Jennifer G; Lababidi, Samir; Yang, Amy X; Lo Surdo, Jessica L; Bauer, Steven R; Puri, Raj K

    2014-04-28

    Human multipotent stromal cells (MSCs) isolated from bone marrow or other tissue sources have great potential to treat a wide range of injuries and disorders in the field of regenerative medicine and tissue engineering. In particular, MSCs have inherent characteristics to suppress the immune system and are being studied in clinical studies to prevent graft-versus-host disease. MSCs can be expanded in vitro and have potential for differentiation into multiple cell lineages. However, the impact of cell passaging on gene expression and function of the cells has not been determined. Commercially available human MSCs derived from bone marrow from six different donors, grown under identical culture conditions and harvested at cell passages 3, 5, and 7, were analyzed with gene-expression profiling by using microarray technology. The phenotype of these cells did not change as reported previously; however, a statistical analysis revealed a set of 78 significant genes that were distinguishable in expression between passages 3 and 7. None of these significant genes corresponded to the markers established by the International Society for Cellular Therapy (ISCT) for MSC identification. When the significant gene lists were analyzed through pathway analysis, these genes were involved in the top-scoring networks of cellular growth and proliferation and cellular development. A meta-analysis of the literature for significant genes revealed that the MSCs seem to be undergoing differentiation into a senescent cell type when cultured extensively. Consistent with the differences in gene expression at passage 3 and 7, MSCs exhibited a significantly greater potential for cell division at passage 3 in comparison to passage 7. Our results identified specific gene markers that distinguish aging MSCs grown in cell culture. Confirmatory studies are needed to correlate these molecular markers with biologic attributes that may facilitate the development of assays to test the quality of MSCs

  4. PECULIARITIES OF SECONDARY METABOLITES BIOSYNTHESIS IN PLANT CELL CULTURES

    Directory of Open Access Journals (Sweden)

    A.M. NOSOV

    2014-06-01

    Full Text Available metabolites formation in plant cell cultures of Panax spp., (ginsenosides; Dioscorea deltoidea (steroid glycosides; Ajuga reptans, Serratula coronata, Rhaponticum carthamoides (ecdisteroids; Polyscias spp., (triterpene glycosides, Taxus spp. (taxoids, Stevia rebaudiana (diterpene steviol-glycosides, Stephania glabra (alkaloids. They are some regular trends of secondary metabolites synthesis in the plant cell culture:It can be noted the stable synthesis of the compound promoting cell proliferation. Indeed, cell cultures of Dioscorea deltoidea were demonstrated to accumulate only furostanol glycosides, which promoted cell division. Furostanol glycoside content of Dioscorea strain DM-0.5 was up to 6 - 12% by dry biomass.Panax ginseng and P. japonicus plant cell cultures synthesize as minimum seven triterpene glycosides (ginsenosides, the productivity of these compounds was up to 6.0 - 8.0% on dry biomass.By contrast, the detectable synthesis of diterpene steviol-glycosides in cultivated cells of Stevia rebaudiana initiated in the mixotrophic cultures during chloroplast formation only.Despite these differences, or mainly due to them, plant cell cultures have become an attractive source of phytochemicals in alternative to collecting wild plants. It provides a guideline to bioreactor-based production of isoprenoids using undifferentiated plant cell cultures

  5. Primary cell culture of human adenocarcinomas--practical considerations.

    Science.gov (United States)

    Lerescu, Lucian; Tucureanu, Cătălin; Caraş, Iuliana; Neagu, Stefan; Melinceanu, Laura; Sălăgeanu, Aurora

    2008-01-01

    Cell culture is one of the major tools for oncology research, being an excellent system in which to study the biochemistry and molecular biology associated with individual cancer types and to understand cancer cell physiology. Progress in understanding the biology of any type of carcinoma has been impeded by the inability to culture adequately malignant cells from most epithelial tissues. The ultimate in vitro tumor model would completely reflect the in vivo tumor microenvironment in function and mechanism. Unfortunately, such a model does not currently exist. Homogeneous cell lines that can be continuously propagated on plastic surfaces have been extensively used as a surrogate for tumor environment; however they are very different from the in vivo tumor cells. Model systems involving primary culture represent the situation most closely related to the original tissue although they have a number of disadvantages over cell lines, such as the limited ability to repeat studies with a well characterized culture system that can be used in multiple laboratories. The primary culture may contain many types of stromal and infiltrating cell types potentially complicating the interpretation of data. Yet, their properties better reflect the cellular interactions present in intact tissue. The present article reviews the critical steps in obtaining, routine maintenance and cryopreservation of primary tumor cell cultures, based on information from literature and personal experience on the subject. The article also includes an updated protocol for primary tumor cell isolation and culture.

  6. Chitosan as an adjuvant-like substrate for dendritic cell culture to enhance antitumor effects.

    Science.gov (United States)

    Lin, Yong-Chong; Lou, Pei-Jen; Young, Tai-Horng

    2014-10-01

    To induce monocyte differentiation into dendritic cells (DCs) is the essential protocol for the DC-mediated cancer immunotherapy. In this study, monocytes isolated from mouse bone marrow were cultured on chitosan substrate to evaluate the effect of the chitosan culture system on the induction and tumor protection of DCs. Compared to tissue culture polystyrene (TCPS), the chitosan culture system could enhance monocyte aggregation and detachment with increased MTT reduction activity and expression of DC marker CD11c and LPS co-receptor CD14. Moreover, compared to TCPS, chitosan could enhance lipopolysaccharides (LPS)-stimulated DCs to secrete higher amount of IL-12. More importantly, vaccination of tumor lysate-pulsed DCs harvested from chitosan could increase cytotoxic T-lymphocyte (CTL) activity and showed significantly enhanced anti-tumor effect than those from TCPS. Therefore, the current study demonstrated that a protocol to culture DCs on a less-adherent chitosan substrate followed by treatment with tumor lysate has the potential in future DC-based vaccine application.

  7. Optical Oxygen Sensors for Applications in Microfluidic Cell Culture

    Directory of Open Access Journals (Sweden)

    Samantha M. Grist

    2010-10-01

    Full Text Available The presence and concentration of oxygen in biological systems has a large impact on the behavior and viability of many types of cells, including the differentiation of stem cells or the growth of tumor cells. As a result, the integration of oxygen sensors within cell culture environments presents a powerful tool for quantifying the effects of oxygen concentrations on cell behavior, cell viability, and drug effectiveness. Because microfluidic cell culture environments are a promising alternative to traditional cell culture platforms, there is recent interest in integrating oxygen-sensing mechanisms with microfluidics for cell culture applications. Optical, luminescence-based oxygen sensors, in particular, show great promise in their ability to be integrated with microfluidics and cell culture systems. These sensors can be highly sensitive and do not consume oxygen or generate toxic byproducts in their sensing process. This paper presents a review of previously proposed optical oxygen sensor types, materials and formats most applicable to microfluidic cell culture, and analyzes their suitability for this and other in vitro applications.

  8. Establishment of a Novel Lingual Organoid Culture System: Generation of Organoids Having Mature Keratinized Epithelium from Adult Epithelial Stem Cells

    Science.gov (United States)

    Hisha, Hiroko; Tanaka, Toshihiro; Kanno, Shohei; Tokuyama, Yoko; Komai, Yoshihiro; Ohe, Shuichi; Yanai, Hirotsugu; Omachi, Taichi; Ueno, Hiroo

    2013-11-01

    Despite the strong need for the establishment of a lingual epithelial cell culture system, a simple and convenient culture method has not yet been established. Here, we report the establishment of a novel lingual epithelium organoid culture system using a three-dimensional matrix and growth factors. Histological analyses showed that the generated organoids had both a stratified squamous epithelial cell layer and a stratum corneum. Very recently, we showed via a multicolor lineage tracing method that Bmi1-positive stem cells exist at the base of the epithelial basal layer in the interpapillary pit. Using our new culture system, we found that organoids could be generated by single Bmi1-positive stem cells and that in the established organoids, multiple Bmi1-positive stem cells were generated at the outermost layer. Moreover, we observed that organoids harvested at an early point in culture could be engrafted and maturate in the tongue of recipient mice and that the organoids generated from carcinogen-treated mice had an abnormal morphology. Thus, this culture system presents valuable settings for studying not only the regulatory mechanisms of lingual epithelium but also lingual regeneration and carcinogenesis.

  9. Hair Follicle Melanocyte Cells as a Renewable Source of Melanocytes for Culture and Transplantation

    Directory of Open Access Journals (Sweden)

    Kwon, Ho

    2008-01-01

    Full Text Available Objective: Advances in melanocyte culture techniques have not yet led to reliable clinical methods for treating hypopigmentation disorders. We hypothesized that melanocytes harvested from plucked hair follicles may provide a renewable source of melanocytes for the treatment of hypopigmentation. Methods: Hairs with attached cells from the follicles were plucked from Yucatan pigs and implanted in a collagen-glycosaminoglycan matrix for either immediate or delayed implantation into full-thickness excisional porcine wounds. Wounds were allowed to heal and were biopsied at 2 and 4 weeks, respectively. Results: Fully healed wounds with transplanted hair follicles showed central areas of dark pigmentation corresponding to the location of implanted hair follicles. Corresponding collagen-glycosaminoglycan matrix wounds showed no central areas of pigmentation. Conclusions: Hair follicle--derived melanocytes may potentially serve as a renewable source of pigment-producing cells for treating hypopigmentation disorders.

  10. Ultrastructural study of the TG180 murine sarcoma cell invasion by Toxoplasma gondii: comparison between in vivo and in vitro cell cultures

    Directory of Open Access Journals (Sweden)

    Hugo Marcelo Ribeiro Barbosa

    2000-04-01

    Full Text Available Infection of non-adherent TG180 murine sarcoma cells with Toxoplasma gondii was compared, at the ultrastructural level, in both in vivo and in vitro conditions. Suspensions of 3.0 x 10(6 TG180 cells infected in vitro with 1.0 x 10(6 parasites of the RH strain were harvested between the first and 6th day post-infection and processed for transmission electron microscopy. In vivo infection was made by intraperitoneal inoculation in mice of 1.0 x 10(6 TG180 cells, that were co-inoculated with a parasite suspension at the same cell concentration. Cells were harvested 10, 20, 30 min and 24, 48 h post-inoculation and processed for transmission electron microscopy at the same conditions of the in vitro culture. It was observed TG180 murine sarcoma cells with intense and equivalent intracellular parasitism in both conditions. Host cells with parasitophorous vacuoles containing up to 16 parasites, as well as parasites undergoing mitoses or presenting a bradyzoite-like morphology, were frequently seen in both culture methods.

  11. Coculture of osteoblasts and endothelial cells: optimization of culture medium and cell ratio

    NARCIS (Netherlands)

    Ma, J.; Beucken, J.J. van den; Yang, F.; Both, S.K.; Cui, F.Z.; Pan, J.; Jansen, J.A.

    2011-01-01

    Vascularization strategies in cell-based bone tissue engineering depend on optimal culture conditions. The present study aimed to determine optimal cell culture medium and cell ratio for cocultures of human marrow stromal cells (HMSCs) and human umbilical vein endothelial cells (HUVECs) in view of

  12. Core–shell heterostructured metal oxide arrays enable superior light-harvesting and hysteresis-free mesoscopic perovskite solar cells

    KAUST Repository

    Mahmood, Khalid

    2015-01-01

    To achieve highly efficient mesoscopic perovskite solar cells (PSCs), the structure and properties of an electron transport layer (ETL) or material (ETM) have been shown to be of supreme importance. Particularly, the core-shell heterostructured mesoscopic ETM architecture has been recognized as a successful electrode design, because of its large internal surface area, superior light-harvesting efficiency and its ability to achieve fast charge transport. Here we report the successful fabrication of a hysteresis-free, 15.3% efficient PSC using vertically aligned ZnO nanorod/TiO2 shell (ZNR/TS) core-shell heterostructured ETMs for the first time. We have also added a conjugated polyelectrolyte polymer into the growth solution to promote the growth of high aspect ratio (AR) ZNRs and substantially improve the infiltration of the perovskite light absorber into the ETM. The PSCs based on the as-synthesized core-shell ZnO/TiO2 heterostructured ETMs exhibited excellent performance enhancement credited to the superior light harvesting capability, larger surface area, prolonged charge-transport pathways and lower recombination rate. The unique ETM design together with minimal hysteresis introduces core-shell ZnO/TiO2 heterostructures as a promising mesoscopic electrode approach for the fabrication of efficient PSCs. This journal is © The Royal Society of Chemistry.

  13. Biologic characteristics of fibroblast cells cultured from the knee ligaments

    Institute of Scientific and Technical Information of China (English)

    陈鸿辉; 唐毅; 李斯明; 沈雁; 刘向荣; 钟灿灿

    2002-01-01

    Objective: To culture fibroblast cells from the kneeligaments and to study the biological characteristics of thesecells.Methods: Cells of the anterior cruciate ligament(ACL) and the medial collateral ligament (MCL) fromNew Zealand white rabbit were cultured in vitro. Cellulargrowth and expression of the collagen were analyzed.Moreover, an in vitro wound closure model was establishedand the healing of the ACL and the MCL cells wascompared.Results: Maximal growth for all these cells wereobtained with Dulbecco's modified Eagle's mediumsupplemented with 10% fetal bovine serum, but RPMI 1640and Ham's F12 media were not suitable to maintain thesecells. Morphology of both ACL and MCL cells from NewZealand white rabbit was alike in vitro, but the MCL cellsgrew faster than the ACL cells. Both cell types producedsimilar amount of collagen in culture, but the ratio ofcollage type I to type III produced by ACL cells was higherthan that produced by MCL cells. Wound closure assayshowed that at 36 hours after injury, cell-free zones createdin the ACL cultures were occupied partially by the ACLcells; in contrast, the wounded zone in the MCL cultureswas almost completely covered by the cells.Conclusions: Although the ACL cells and the MCLcells from New Zealand white rabbit show similarappearance in morphology in culture, the cellular growthand the biochemical synthesis of collagen as well as thehealing in vitro were significantly different. Thesedifferences in intrinsic properties of the two types of cells invitro might contribute to the differential healing potentialsof these ligaments in vivo.

  14. LIF-free embryonic stem cell culture in simulated microgravity.

    Directory of Open Access Journals (Sweden)

    Yumi Kawahara

    Full Text Available BACKGROUND: Leukemia inhibitory factor (LIF is an indispensable factor for maintaining mouse embryonic stem (ES cell pluripotency. A feeder layer and serum are also needed to maintain an undifferentiated state, however, such animal derived materials need to be eliminated for clinical applications. Therefore, a more reliable ES cell culture technique is required. METHODOLOGY/PRINCIPAL FINDINGS: We cultured mouse ES cells in simulated microgravity using a 3D-clinostat. We used feeder-free and serum-free media without LIF. CONCLUSIONS/SIGNIFICANCE: Here we show that simulated microgravity allows novel LIF-free and animal derived material-free culture methods for mouse ES cells.

  15. Long-term maintenance of human induced pluripotent stem cells by automated cell culture system.

    Science.gov (United States)

    Konagaya, Shuhei; Ando, Takeshi; Yamauchi, Toshiaki; Suemori, Hirofumi; Iwata, Hiroo

    2015-11-17

    Pluripotent stem cells, such as embryonic stem cells and induced pluripotent stem (iPS) cells, are regarded as new sources for cell replacement therapy. These cells can unlimitedly expand under undifferentiated conditions and be differentiated into multiple cell types. Automated culture systems enable the large-scale production of cells. In addition to reducing the time and effort of researchers, an automated culture system improves the reproducibility of cell cultures. In the present study, we newly designed a fully automated cell culture system for human iPS maintenance. Using an automated culture system, hiPS cells maintained their undifferentiated state for 60 days. Automatically prepared hiPS cells had a potency of differentiation into three germ layer cells including dopaminergic neurons and pancreatic cells.

  16. Senescent vs. non-senescent cells in the human annulus in vivo: Cell harvest with laser capture microdissection and gene expression studies with microarray analysis

    Directory of Open Access Journals (Sweden)

    Ingram Jane A

    2010-01-01

    Full Text Available Abstract Background Senescent cells are well-recognized in the aging/degenerating human disc. Senescent cells are viable, cannot divide, remain metabolically active and accumulate within the disc over time. Molecular analysis of senescent cells in tissue offers a special challenge since there are no cell surface markers for senescence which would let one use fluorescence-activated cell sorting as a method for separating out senescent cells. Methods We employed a novel laser capture microdissection (LCM design to selectively harvest senescent and non-senescent annulus cells in paraffin-embedded tissue, and compared their gene expression with microarray analysis. LCM was used to separately harvest senescent and non-senescent cells from 11 human annulus specimens. Results Microarray analysis revealed significant differences in expression levels in senescent cells vs non-senescent cells: 292 genes were upregulated, and 321 downregulated. Genes with established relationships to senescence were found to be significantly upregulated in senescent cells vs. non-senescent cells: p38 (MPAK14, RB-Associated KRAB zinc finger, Discoidin, CUB and LCCL domain, growth arrest and DNA-damage inducible beta, p28ING5, sphingosine-1-phosphate receptor 2 and somatostatin receptor 3; cyclin-dependent kinase 8 showed significant downregulation in senescent cells. Nitric oxidase synthase 1, and heat shock 70 kDa protein 6, both of which were significantly down-regulated in senescent cells, also showed significant changes. Additional genes related to cytokines, cell proliferation, and other processes were also identified. Conclusions Our LCM-microarray analyses identified a set of genes associated with senescence which were significantly upregulated in senescent vs non-senescent cells in the human annulus. These genes include p38 MAP kinase, discoidin, inhibitor of growth family member 5, and growth arrest and DNA-damage-inducible beta. Other genes, including genes

  17. Colorimetric pH measurement of animal cell culture media.

    Science.gov (United States)

    Jang, Juno; Moon, Soo-Jin; Hong, Sung-Hwan; Kim, Ik-Hwan

    2010-11-01

    Most animal cell culture media can be buffered using bicarbonate and high pressure CO(2) in a closed system. However, in an open system, the pH of the culture media increases continuously due to the marked difference in CO(2) pressure between the culture media and the atmosphere. Therefore, it is important to measure the exact pH of the culture media in an intact closed system. In this study, a pH measurement method was developed using visible light. The pH was calculated from light absorbance by the cells and by the culture media. This method was successfully applied to both suspension and anchorage-dependent cell cultures.

  18. Novel culturing platform for brain slices and neuronal cells

    DEFF Research Database (Denmark)

    Svendsen, Winnie Edith; Al Atraktchi, Fatima Al-Zahraa; Bakmand, Tanya

    2015-01-01

    In this paper we demonstrate a novel culturing system for brain slices and neuronal cells, which can control the concentration of nutrients and the waste removal from the culture by adjusting the fluid flow within the device. The entire system can be placed in an incubator. The system has been te...... tested successfully with brain slices and PC12 cells. The culture substrate can be modified using metal electrodes and/or nanostructures for conducting electrical measurements while culturing and for better mimicking the in vivo conditions.......In this paper we demonstrate a novel culturing system for brain slices and neuronal cells, which can control the concentration of nutrients and the waste removal from the culture by adjusting the fluid flow within the device. The entire system can be placed in an incubator. The system has been...

  19. Development of an algorithm for production of inactivated arbovirus antigens in cell culture.

    Science.gov (United States)

    Goodman, C H; Russell, B J; Velez, J O; Laven, J J; Nicholson, W L; Bagarozzi, D A; Moon, J L; Bedi, K; Johnson, B W

    2014-11-01

    Arboviruses are medically important pathogens that cause human disease ranging from a mild fever to encephalitis. Laboratory diagnosis is essential to differentiate arbovirus infections from other pathogens with similar clinical manifestations. The Arboviral Diseases Branch (ADB) reference laboratory at the CDC Division of Vector-Borne Diseases (DVBD) produces reference antigens used in serological assays such as the virus-specific immunoglobulin M antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA). Antigen production in cell culture has largely replaced the use of suckling mice; however, the methods are not directly transferable. The development of a cell culture antigen production algorithm for nine arboviruses from the three main arbovirus families, Flaviviridae, Togaviridae, and Bunyaviridae, is described here. Virus cell culture growth and harvest conditions were optimized, inactivation methods were evaluated, and concentration procedures were compared for each virus. Antigen performance was evaluated by the MAC-ELISA at each step of the procedure. The antigen production algorithm is a framework for standardization of methodology and quality control; however, a single antigen production protocol was not applicable to all arboviruses and needed to be optimized for each virus.

  20. [Application of cell co-culture techniques in medical studies].

    Science.gov (United States)

    Luo, Yun; Sun, Gui-Bo; Qin, Meng; Yao, Fan; Sun, Xiao-Bo

    2012-11-01

    As the cell co-culture techniques can better imitate an in vivo environment, it is helpful in observing the interactions among cells and between cells and the culture environment, exploring the effect mechanisms of drugs and their possible targets and filling the gaps between the mono-layer cell culture and the whole animal experiments. In recently years, they has attracted much more attention from the medical sector, and thus becoming one of research hotspots in drug research and development and bio-pharmaceutical fields. The cell co-culture techniques, including direct and indirect methods, are mainly used for studying pathological basis, new-type treatment methods and drug activity screening. Existing cell co-culture techniques are used for more pharmacological studies on single drug and less studies on interaction of combined drugs, such as collaborative compatibility and attenuation and synergistic effect among traditional Chinese medicines (TCMs). In line with the action characteristics of multi-component and multi-target, the cell co-culture techniques provide certain reference value for future studies on the effect and mechanism of combined TCMs on organisms as well as new methods for studies on TCMs and their compounds. This essay summarizes cell co-culture methods and their application and look into the future of their application in studies on TCMs and compounds.

  1. Culture materials affect ex vivo expansion of hematopoietic progenitor cells.

    Science.gov (United States)

    LaIuppa, J A; McAdams, T A; Papoutsakis, E T; Miller, W M

    1997-09-01

    Ex vivo expansion of hematopoietic cells is important for applications such as cancer treatment, gene therapy, and transfusion medicine. While cell culture systems are widely used to evaluate the biocompatibility of materials for implantation, the ability of materials to support proliferation of primary human cells in cultures for reinfusion into patients has not been addressed. We screened a variety of commercially available polymer (15 types), metal (four types), and glass substrates for their ability to support expansion of hematopoietic cells when cultured under conditions that would be encountered in a clinical setting. Cultures of peripheral blood (PB) CD34+ cells and mononuclear cells (MNC) were evaluated for expansion of total cells and colony-forming unit-granulocyte monocyte (CFU-GM; progenitors committed to the granulocyte and/or monocyte lineage). Human hematopoietic cultures in serum-free medium were found to be extremely sensitive to the substrate material. The only materials tested that supported expansion at or near the levels of polystyrene were tissue culture polystyrene, Teflon perfluoroalkoxy, Teflon fluorinated ethylene propylene, cellulose acetate, titanium, new polycarbonate, and new polymethylpentene. MNC were less sensitive to the substrate materials than the primitive CD34+ progenitors, although similar trends were seen for expansion of the two cell populations on the substrates tested. CFU-GM expansion was more sensitive to substrate materials than was total cell expansion. The detrimental effects of a number of the materials on hematopoietic cultures appear to be caused by protein adsorption and/or leaching of toxins. Factors such as cleaning, sterilization, and reuse significantly affected the performance of some materials as culture substrates. We also used PB CD34+ cell cultures to examine the biocompatibility of gas-permeable cell culture and blood storage bags and several types of tubing commonly used with biomedical equipment

  2. Culturing Schwann Cells from Neonatal Rats by Improved Enzyme Digestion Combined with Explants-culture Method.

    Science.gov (United States)

    Liu, Di; Liang, Xiao-Chun; Zhang, Hong

    2016-08-01

    Objective To develop an improved method for culturing Schwann cells(SCs) by using both enzyme digestion and explants-culture approaches and compared with traditional explants-culture method and general hemi-explants-culture method. Methods Bilaterally sciatic nerves and brachial plexus nerves were dissected from 3 to 5-day-old neonatal SD rats and explants-culture method,general hemi-explants-culture method,and improved enzyme digestion combined with explants-culture method were adopted to culture SCs,respectively. SCs were digested and passaged after 7 days in culture and counted under the microscope. The purity of SCs was identified by S-100 immunofluorescence staining. Results The SCs of improved method group grew fastest and the total number of cells obtained was(1.85±0.13)×10(6);the SCs of the hemi-explants-culture method group grew slower than the improved method group and the total number of cells obtained was (1.10±0.10)×10(6);the SCs of the explants-culture method group grew slowest and the total number of cells obtained was (0.77±0.03)×10(6).The total number of cells obtained showed significant difference among the three groups(Pculture method group,and (74.50±4.23)% in the explants-culture method group(Pculture method can obtain sufficient amount of high-purity SCs in a short time and thus may be applied in further research on peripheral nerve regeneration.

  3. Cell cycle regulation in human embryonic stem cells: links to adaptation to cell culture.

    Science.gov (United States)

    Barta, Tomas; Dolezalova, Dasa; Holubcova, Zuzana; Hampl, Ales

    2013-03-01

    Cell cycle represents not only a tightly orchestrated mechanism of cell replication and cell division but it also plays an important role in regulation of cell fate decision. Particularly in the context of pluripotent stem cells or multipotent progenitor cells, regulation of cell fate decision is of paramount importance. It has been shown that human embryonic stem cells (hESCs) show unique cell cycle characteristics, such as short doubling time due to abbreviated G1 phase; these properties change with the onset of differentiation. This review summarizes the current understanding of cell cycle regulation in hESCs. We discuss cell cycle properties as well as regulatory machinery governing cell cycle progression of undifferentiated hESCs. Additionally, we provide evidence that long-term culture of hESCs is accompanied by changes in cell cycle properties as well as configuration of several cell cycle regulatory molecules.

  4. In vitro bone formation by human marrow cell culture on the surface of zinc-releasing calcium phosphate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Ikeuchi, M.; Noshi, T.; Horiuchi, K.; Yamamoto, K.; Sugimura, M. [Nara Medical Univ., Kashihara (Japan). Dept. of Oral and Maxillofacial Surgery; Dohi, Y. [Nara Medical Univ., Kashihara (Japan). Dept. of Public Health; Ohgushi, H. [Nara Medical Univ., Kashihara (Japan). Dept. of Orthopedics; Ito, A. [National Inst. for Advanced Interdisciplinary Research, MITI, Ibaraki (Japan)

    2001-07-01

    We examined the effect of zinc on the osteogenic differentiation of cultured human marrow cells on the surface of zinc-releasing TCP/HAP (Zn-TCP/HAP) ceramics in the shape of a disk. Three ml of human bone marrow harvested from the ilium was cultured in a medium containing 15% fetal bovine serum to reach confluent. After trypsinization, the cells were seeded at 20 x 10{sup 3} cells/16 mm {phi} on Falcon tissue wells with the ceramic disks (TCP/HAP containing 0, 0.32, 0.42, 0.63, 0.88 and 1.26 wt% Zn). After 2 weeks of subculture in the presence of {beta}-glycerophosphate, vitamin C phosphate, and dexamethasone (Dex), the cells were stained for alkaline phosphatase (ALP). The ALP stain was strengthened as zinc content of the disk increased. The data demonstrated that Zn-TCP/HAP influenced cell differentiation in human marrow cell culture and resulted in high osteoblastic activity. Furthermore, ALP activities of the cell layer significantly increased depending on zinc content of the disk in the presence of Dex. These results indicate that the surface of Zn-TCP/HAP stimulates osteogenic differentiation in human cultured marrow cells as well as in rat ones. Thus, Zn-TCP/HAP ceramics are expected to be useful materials for bone reconstructive surgery. (orig.)

  5. Isolation and differentiation potential of human mesenchymal stem cells from adipose tissue harvested by water jet-assisted liposuction.

    Science.gov (United States)

    Meyer, Juliane; Salamon, Achim; Herzmann, Nicole; Adam, Stefanie; Kleine, Hans-Dieter; Matthiesen, Inge; Ueberreiter, Klaus; Peters, Kirsten

    2015-11-01

    In recent years the therapeutic application of extracted adipose tissue for autologous fat grafting and the application of adipose tissue-derived mesenchymal stem cells (adMSC) isolated thereof has progressed. Water-jet assisted liposuction (WAL) is 1 procedure for harvesting adipose tissue and provides a favorable aesthetic outcome combined with high tissue protection. Tissue aspirated by WAL has been successfully applied in grafting procedures. The aims of this study were to confirm the tissue viability and to understand the abundance and mesenchymal differentiation capacity of stem cells within the tissue. We analyzed tissue integrity of WAL tissue particles via fluorescence microscopy. The adMSC content was determined by isolating the cells from the tissue. The mesenchymal differentiation capacity was confirmed with cytochemical staining methods. The stromal vascular fraction of WAL tissue showed high viability and contained an average of 2.6 × 105 CD34-positive cells per milliliter of tissue. Thus WAL tissue contains a high number of stem cells. Furthermore adMSC isolated from WAL tissue showed typical mesenchymal differentiation potential. WAL of adipose tissue is well suited for autologous fat grafting because it retains tissue viability. Furthermore it is a valid source for the subsequent isolation of adMSC with multipotent differentiation potential. 3 Therapeutic. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

  6. LIF-Free Embryonic Stem Cell Culture in Simulated Microgravity

    OpenAIRE

    Yumi Kawahara; Tomotaka Manabe; Masaya Matsumoto; Teruyuki Kajiume; Masayasu Matsumoto; Louis Yuge

    2009-01-01

    BACKGROUND: Leukemia inhibitory factor (LIF) is an indispensable factor for maintaining mouse embryonic stem (ES) cell pluripotency. A feeder layer and serum are also needed to maintain an undifferentiated state, however, such animal derived materials need to be eliminated for clinical applications. Therefore, a more reliable ES cell culture technique is required. METHODOLOGY/PRINCIPAL FINDINGS: We cultured mouse ES cells in simulated microgravity using a 3D-clinostat. We used feeder-free and...

  7. Three-dimensional cell culture models for investigating human viruses.

    Science.gov (United States)

    He, Bing; Chen, Guomin; Zeng, Yi

    2016-10-01

    Three-dimensional (3D) culture models are physiologically relevant, as they provide reproducible results, experimental flexibility and can be adapted for high-throughput experiments. Moreover, these models bridge the gap between traditional two-dimensional (2D) monolayer cultures and animal models. 3D culture systems have significantly advanced basic cell science and tissue engineering, especially in the fields of cell biology and physiology, stem cell research, regenerative medicine, cancer research, drug discovery, and gene and protein expression studies. In addition, 3D models can provide unique insight into bacteriology, virology, parasitology and host-pathogen interactions. This review summarizes and analyzes recent progress in human virological research with 3D cell culture models. We discuss viral growth, replication, proliferation, infection, virus-host interactions and antiviral drugs in 3D culture models.

  8. Multizone Paper Platform for 3D Cell Cultures

    Science.gov (United States)

    Derda, Ratmir; Hong, Estrella; Mwangi, Martin; Mammoto, Akiko; Ingber, Donald E.; Whitesides, George M.

    2011-01-01

    In vitro 3D culture is an important model for tissues in vivo. Cells in different locations of 3D tissues are physiologically different, because they are exposed to different concentrations of oxygen, nutrients, and signaling molecules, and to other environmental factors (temperature, mechanical stress, etc). The majority of high-throughput assays based on 3D cultures, however, can only detect the average behavior of cells in the whole 3D construct. Isolation of cells from specific regions of 3D cultures is possible, but relies on low-throughput techniques such as tissue sectioning and micromanipulation. Based on a procedure reported previously (“cells-in-gels-in-paper” or CiGiP), this paper describes a simple method for culture of arrays of thin planar sections of tissues, either alone or stacked to create more complex 3D tissue structures. This procedure starts with sheets of paper patterned with hydrophobic regions that form 96 hydrophilic zones. Serial spotting of cells suspended in extracellular matrix (ECM) gel onto the patterned paper creates an array of 200 micron-thick slabs of ECM gel (supported mechanically by cellulose fibers) containing cells. Stacking the sheets with zones aligned on top of one another assembles 96 3D multilayer constructs. De-stacking the layers of the 3D culture, by peeling apart the sheets of paper, “sections” all 96 cultures at once. It is, thus, simple to isolate 200-micron-thick cell-containing slabs from each 3D culture in the 96-zone array. Because the 3D cultures are assembled from multiple layers, the number of cells plated initially in each layer determines the spatial distribution of cells in the stacked 3D cultures. This capability made it possible to compare the growth of 3D tumor models of different spatial composition, and to examine the migration of cells in these structures. PMID:21573103

  9. Microfluidic cardiac cell culture model (μCCCM).

    Science.gov (United States)

    Giridharan, Guruprasad A; Nguyen, Mai-Dung; Estrada, Rosendo; Parichehreh, Vahidreza; Hamid, Tariq; Ismahil, Mohamed Ameen; Prabhu, Sumanth D; Sethu, Palaniappan

    2010-09-15

    Physiological heart development and cardiac function rely on the response of cardiac cells to mechanical stress during hemodynamic loading and unloading. These stresses, especially if sustained, can induce changes in cell structure, contractile function, and gene expression. Current cell culture techniques commonly fail to adequately replicate physical loading observed in the native heart. Therefore, there is a need for physiologically relevant in vitro models that recreate mechanical loading conditions seen in both normal and pathological conditions. To fulfill this need, we have developed a microfluidic cardiac cell culture model (μCCCM) that for the first time allows in vitro hemodynamic stimulation of cardiomyocytes by directly coupling cell structure and function with fluid induced loading. Cells are cultured in a small (1 cm diameter) cell culture chamber on a thin flexible silicone membrane. Integrating the cell culture chamber with a pump, collapsible pulsatile valve and an adjustable resistance element (hemostatic valve) in series allow replication of various loading conditions experienced in the heart. This paper details the design, modeling, fabrication and characterization of fluid flow, pressure and stretch generated at various frequencies to mimic hemodynamic conditions associated with the normal and failing heart. Proof-of-concept studies demonstrate successful culture of an embryonic cardiomyoblast line (H9c2 cells) and establishment of an in vivo like phenotype within this system.

  10. Isolating highly pure rat spermatogonial stem cells in culture.

    Science.gov (United States)

    Hamra, F Kent; Chapman, Karen M; Wu, Zhuoru; Garbers, David L

    2008-01-01

    Methods are detailed for isolating highly pure populations of spermatogonial stem cells from primary cultures of testis cells prepared from 22- to 24-day-old rats. The procedure is based on the principle that testicular somatic cells bind tightly to plastic and collagen matrices when cultured in serum-containing medium, whereas spermatogonia and spermatocytes do not bind to plastic or collagen when cultured in serum-containing medium. The collagen-non-binding testis cells obtained using these procedures are thus approx. 97% pure spermatogenic cells. Stem spermatogonia are then easily isolated from the purified spermatogenic population during a short incubation step in culture on laminin matrix. The spermatogenic cells that bind to laminin are more than 90% undifferentiated, type A spermatogonia and are greatly enriched in genetically modifiable stem cells that can develop into functional spermatozoa. This method does not require flow cytometry and can also be applied to obtain enriched cultures of mouse spermatogonial stem cells. The isolated spermatogonia provide a highly potent and effective source of stem cells that have been used to initiate in vitro and in vivo culture studies on spermatogenesis.

  11. Three Dimensional Culture of Human Renal Cell Carcinoma Organoids.

    Directory of Open Access Journals (Sweden)

    Cynthia A Batchelder

    Full Text Available Renal cell carcinomas arise from the nephron but are heterogeneous in disease biology, clinical behavior, prognosis, and response to systemic therapy. Development of patient-specific in vitro models that efficiently and faithfully reproduce the in vivo phenotype may provide a means to develop personalized therapies for this diverse carcinoma. Studies to maintain and model tumor phenotypes in vitro were conducted with emerging three-dimensional culture techniques and natural scaffolding materials. Human renal cell carcinomas were individually characterized by histology, immunohistochemistry, and quantitative PCR to establish the characteristics of each tumor. Isolated cells were cultured on renal extracellular matrix and compared to a novel polysaccharide scaffold to assess cell-scaffold interactions, development of organoids, and maintenance of gene expression signatures over time in culture. Renal cell carcinomas cultured on renal extracellular matrix repopulated tubules or vessel lumens in renal pyramids and medullary rays, but cells were not observed in glomeruli or outer cortical regions of the scaffold. In the polysaccharide scaffold, renal cell carcinomas formed aggregates that were loosely attached to the scaffold or free-floating within the matrix. Molecular analysis of cell-scaffold constructs including immunohistochemistry and quantitative PCR demonstrated that individual tumor phenotypes could be sustained for up to 21 days in culture on both scaffolds, and in comparison to outcomes in two-dimensional monolayer cultures. The use of three-dimensional scaffolds to engineer a personalized in vitro renal cell carcinoma model provides opportunities to advance understanding of this disease.

  12. Mammalian Cell Culture Clarification: A Case Study Using Chimeric Anti-CEA Monoclonal Antibodies

    Directory of Open Access Journals (Sweden)

    Mohamed Ali Abol Hassan

    2011-12-01

    Full Text Available The extracellular expression of monoclonal antibodies (mAbs in mammalian cell culture provides both opportunities and restrictions for the design of robust harvest and clarification operations. With advances in cell culture media and cell lines, it is now possible to achieve high titers of over 5 g/l for mAbs. However, Mammalian cells are sensitive to breakage due to shear stress that can result in release of proteases and other host cell proteins (HCPs which eventually affects product stability and purity. There is larger number of mAbs undergoing clinical development and it has placed significant importance on platform technologies of process development. Generally, Centrifugation and microfiltration are the primary harvest techniques used in the industry and depth filtration is also used as a step operation on clarification. This study compares the unit operations; centrifugation, microfiltration and depth filtration for maximum recovery of monoclonal antibodies. The results have shown that the depth filtration as more suitable operation for mammalian cell culture clarification since it gives 96% recovery of mAbs in comparison to centrifugation and microfiltration. ABSTRAK: Pengungkapan luar sel dari antibodi monoklon (monoclonal antibodies ((mAbs dalam kultur sel mamalia memberi ruang dan batasan terhadap reka bentuk penuaian yang cekap dan penerangan operasi. Dengan kemajuan dalam media sel kultur dan cell lines (produk yang berupa sel kekal yang digunakan untuk tujuan kajian biologi, kini adalah berkemungkinan untuk memperolehi titer tinggi melebihi 5g/l untuk mAbs [2]. Walaupun begitu, sel mamalia sensitif terhadap retakan disebabkan tegasan ricih yang menyebabkan pengeluaran protease dan hos sel protein yang lain, (host cell proteins (HCPs akhirnya mempengaruhi kestabilan dan keaslian produk. Terdapat mAbs dalam jumlah besar yang masih menjalani pembangunan klinikal dan sesungguhnya ini penting sebagai satu landasan teknologi dalam

  13. Harvesting the potential of the human umbilical cord: isolation and characterisation of four cell types for tissue engineering applications.

    Science.gov (United States)

    Hayward, Cindy J; Fradette, Julie; Galbraith, Todd; Rémy, Murielle; Guignard, Rina; Gauvin, Robert; Germain, Lucie; Auger, François A

    2013-01-01

    The human umbilical cord (UC) has attracted interest as a source of cells for many research applications. UC solid tissues contain four cell types: epithelial, stromal, smooth muscle and endothelial cells. We have developed a unique protocol for the sequential extraction of all four cell types from a single UC, allowing tissue reconstruction using multiple cell types from the same source. By combining perfusion, immersion and explant techniques, all four cell types have been successfully expanded in monolayer cultures. We have also characterised epithelial and Wharton's jelly cells (WJC) by immunolabelling of specific proteins. Epithelial cell yields averaged at 2.3 × 10(5) cells per centimetre UC, and the cells expressed an unusual combination of keratins typical of simple, mucous and stratified epithelia. Stromal cells in the Wharton's jelly expressed desmin, α-smooth muscle actin, elastin, keratins (K12, K16, K18 and K19), vimentin and collagens. Expression patterns in cultured cells resembled those found in situ except for basement membrane components and type III collagen. These stromal cells featured a sustained proliferation rate up to passage 12 after thawing. The mesenchymal stem cell (MSC) character of the WJC was confirmed by their expression of typical MSC surface markers and by adipogenic and osteogenic differentiation assays. To emphasise and demonstrate their potential for regenerative medicine, UC cell types were successfully used to produce human tissue-engineered constructs. Both bilayered stromal/epithelial and vascular substitutes were produced, establishing the versatility and importance of these cells for research and therapeutic applications.

  14. Development of bone marrow mesenchymal stem cell culture in vitro

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; PENG Li-pan; WU Nan; LI Le-ping

    2012-01-01

    Objective To review the in vitro development of bone marrow mesenchymal stem cells culture (BM-MSC).Data sources The data cited in this review were mainly obtained from articles listed in Medline and PubMed.The search terms were “bone marrow mesenchymal stem cell" and "cell culture".Study selection Articles regarding the in vitro development of BM-MSCs culture,as well as the challenge of optimizing cell culture environment in two-dimensional (2D) vs.3D.Results Improving the culture conditions increases the proliferation and reduces the differentiation.Optimal values for many culture parameters remain to be identified.Expansion of BM-MSCs under defined conditions remains challenging,including the development of optimal culture conditions for BMSC and large-volume production systems.Conclusions Expansion of BM-MSCs under defined conditions remains challenges,including the development of optimal culture conditions for BMSC and scale-up to large-volume production systems.Optimal values for many culture parameters remain to be identified.

  15. THE ULTRASTRUCTURE OF SEPARATED AND CULTURED CELL OF PORPHYRA YEZOENSIS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    There are many reports that cells (protoplasts) separated from the thallus of Porphyra by enzyme can develop to normal leafy thalli in the same way as monospores. But there are few investigations on the subcellular structure of the isolated vegetative cell for comparison with the subcellular structure of monospores. To clarify whether the separated and cultured cells undergo the same or similar ultrastructure changes during culture and germination as monospores undergo in their formation and germination, we observed their ultrastructure, compared them with those of the monospore and found that the ultrastructure of separated and cultured cells did not have the characteristic feature as that of monospore formation, such as production of small and large fibrous vesicles, but was accompanied by vacuolation and starch mobilization like that in monospore germination. The paper also discusses the relations between monospores and separated and cultured cells.

  16. Energy harvester

    NARCIS (Netherlands)

    Herder, J.L.; Tolou, N.

    2013-01-01

    Energy harvester comprising a mass (2) that is subjectable to environmental forces for bringing it into the status of a moving mass, and means (5) linked to the mass (2) for converting and storing of energy embodied in the moving mass, which means (5) are arranged for subsequent release of said ener

  17. Quantitative volumetric Raman imaging of three dimensional cell cultures

    Science.gov (United States)

    Kallepitis, Charalambos; Bergholt, Mads S.; Mazo, Manuel M.; Leonardo, Vincent; Skaalure, Stacey C.; Maynard, Stephanie A.; Stevens, Molly M.

    2017-03-01

    The ability to simultaneously image multiple biomolecules in biologically relevant three-dimensional (3D) cell culture environments would contribute greatly to the understanding of complex cellular mechanisms and cell-material interactions. Here, we present a computational framework for label-free quantitative volumetric Raman imaging (qVRI). We apply qVRI to a selection of biological systems: human pluripotent stem cells with their cardiac derivatives, monocytes and monocyte-derived macrophages in conventional cell culture systems and mesenchymal stem cells inside biomimetic hydrogels that supplied a 3D cell culture environment. We demonstrate visualization and quantification of fine details in cell shape, cytoplasm, nucleus, lipid bodies and cytoskeletal structures in 3D with unprecedented biomolecular specificity for vibrational microspectroscopy.

  18. Surface modified alginate microcapsules for 3D cell culture

    Science.gov (United States)

    Chen, Yi-Wen; Kuo, Chiung Wen; Chueh, Di-Yen; Chen, Peilin

    2016-06-01

    Culture as three dimensional cell aggregates or spheroids can offer an ideal platform for tissue engineering applications and for pharmaceutical screening. Such 3D culture models, however, may suffer from the problems such as immune response and ineffective and cumbersome culture. This paper describes a simple method for producing microcapsules with alginate cores and a thin shell of poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) to encapsulate mouse induced pluripotent stem (miPS) cells, generating a non-fouling surface as an effective immunoisolation barrier. We demonstrated the trapping of the alginate microcapsules in a microwell array for the continuous observation and culture of a large number of encapsulated miPS cells in parallel. miPS cells cultured in the microcapsules survived well and proliferated to form a single cell aggregate. Droplet formation of monodisperse microcapsules with controlled size combined with flow cytometry provided an efficient way to quantitatively analyze the growth of encapsulated cells in a high-throughput manner. The simple and cost-effective coating technique employed to produce the core-shell microcapsules could be used in the emerging field of cell therapy. The microwell array would provide a convenient, user friendly and high-throughput platform for long-term cell culture and monitoring.

  19. Nylon-3 polymers that enable selective culture of endothelial cells.

    Science.gov (United States)

    Liu, Runhui; Chen, Xinyu; Gellman, Samuel H; Masters, Kristyn S

    2013-11-06

    Substrates that selectively encourage the growth of specific cell types are valuable for the engineering of complex tissues. Some cell-selective peptides have been identified from extracellular matrix proteins; these peptides have proven useful for biomaterials-based approaches to tissue repair or regeneration. However, there are very few examples of synthetic materials that display selectivity in supporting cell growth. We describe nylon-3 polymers that support in vitro culture of endothelial cells but do not support the culture of smooth muscle cells or fibroblasts. These materials may be promising for vascular biomaterials applications.

  20. Fundamentals of microfluidic cell culture in controlled microenvironments.

    Science.gov (United States)

    Young, Edmond W K; Beebe, David J

    2010-03-01

    Microfluidics has the potential to revolutionize the way we approach cell biology research. The dimensions of microfluidic channels are well suited to the physical scale of biological cells, and the many advantages of microfluidics make it an attractive platform for new techniques in biology. One of the key benefits of microfluidics for basic biology is the ability to control parameters of the cell microenvironment at relevant length and time scales. Considerable progress has been made in the design and use of novel microfluidic devices for culturing cells and for subsequent treatment and analysis. With the recent pace of scientific discovery, it is becoming increasingly important to evaluate existing tools and techniques, and to synthesize fundamental concepts that would further improve the efficiency of biological research at the microscale. This tutorial review integrates fundamental principles from cell biology and local microenvironments with cell culture techniques and concepts in microfluidics. Culturing cells in microscale environments requires knowledge of multiple disciplines including physics, biochemistry, and engineering. We discuss basic concepts related to the physical and biochemical microenvironments of the cell, physicochemical properties of that microenvironment, cell culture techniques, and practical knowledge of microfluidic device design and operation. We also discuss the most recent advances in microfluidic cell culture and their implications on the future of the field. The goal is to guide new and interested researchers to the important areas and challenges facing the scientific community as we strive toward full integration of microfluidics with biology.

  1. Fundamentals of microfluidic cell culture in controlled microenvironments†

    Science.gov (United States)

    Young, Edmond W. K.; Beebe, David J.

    2010-01-01

    Microfluidics has the potential to revolutionize the way we approach cell biology research. The dimensions of microfluidic channels are well suited to the physical scale of biological cells, and the many advantages of microfluidics make it an attractive platform for new techniques in biology. One of the key benefits of microfluidics for basic biology is the ability to control parameters of the cell microenvironment at relevant length and time scales. Considerable progress has been made in the design and use of novel microfluidic devices for culturing cells and for subsequent treatment and analysis. With the recent pace of scientific discovery, it is becoming increasingly important to evaluate existing tools and techniques, and to synthesize fundamental concepts that would further improve the efficiency of biological research at the microscale. This tutorial review integrates fundamental principles from cell biology and local microenvironments with cell culture techniques and concepts in microfluidics. Culturing cells in microscale environments requires knowledge of multiple disciplines including physics, biochemistry, and engineering. We discuss basic concepts related to the physical and biochemical microenvironments of the cell, physicochemical properties of that microenvironment, cell culture techniques, and practical knowledge of microfluidic device design and operation. We also discuss the most recent advances in microfluidic cell culture and their implications on the future of the field. The goal is to guide new and interested researchers to the important areas and challenges facing the scientific community as we strive toward full integration of microfluidics with biology. PMID:20179823

  2. Controlling the diversity of cell populations in a stem cell culture

    NARCIS (Netherlands)

    Heo, Inha; Clevers, Hans

    2015-01-01

    Culturing intestinal stem cells into 3D organoids results in heterogeneous cell populations, reflecting the in vivo cell type diversity. In a recent paper published in Nature, Wang et al. established a culture condition for a highly homogeneous population of intestinal stem cells.

  3. Controlling the diversity of cell populations in a stem cell culture

    NARCIS (Netherlands)

    Heo, Inha; Clevers, Hans

    2015-01-01

    Culturing intestinal stem cells into 3D organoids results in heterogeneous cell populations, reflecting the in vivo cell type diversity. In a recent paper published in Nature, Wang et al. established a culture condition for a highly homogeneous population of intestinal stem cells.

  4. Umbilical cord Wharton's jelly repeated culture system: a new device and method for obtaining abundant mesenchymal stem cells for bone tissue engineering.

    Directory of Open Access Journals (Sweden)

    Zhengqi Chang

    Full Text Available To date, various types of cells for seeding regenerative scaffolds have been used for bone tissue engineering. Among seed cells, the mesenchymal stem cells derived from human umbilical cord Wharton's jelly (hUCMSCs represent a promising candidate and hold potential for bone tissue engineering due to the the lack of ethical controversies, accessibility, sourced by non-invasive procedures for donors, a reduced risk of contamination, osteogenic differentiation capacities, and higher immunomodulatory capacity. However, the current culture methods are somewhat complicated and inefficient and often fail to make the best use of the umbilical cord (UC tissues. Moreover, these culture processes cannot be performed on a large scale and under strict quality control. As a result, only a small quantity of cells can be harvested using the current culture methods. To solve these problems, we designed and evaluated an UC Wharton's jelly repeated culture device. Using this device, hUCMSCs were obtained from the repeated cultures and their quantities and biological characteristics were compared. We found that using our culture device, which retained all tissue blocks on the bottom of the dish, the total number of obtained cells increased 15-20 times, and the time required for the primary passage was reduced. Moreover, cells harvested from the repeated cultures exhibited no significant difference in their immunophenotype, potential for multilineage differentiation, or proliferative, osteoinductive capacities, and final osteogenesis. The application of the repeated culture frame (RCF not only made full use of the Wharton's jelly but also simplified and specified the culture process, and thus, the culture efficiency was significantly improved. In summary, abundant hUCMSCs of dependable quality can be acquired using the RCF.

  5. Ontogeny of electrically excitable cells in cultured olfactory epithelium.

    OpenAIRE

    Schubert, D; Stallcup, W.; LaCorbiere, M; Kidokoro, Y; Orgel, L

    1985-01-01

    A primary system has been developed in which it is possible to study the production of electrically excitable neuron-like cells from a precursor population of olfactory epithelial cells. Rat nasal epithelium was dissociated and placed in culture. The initial surviving cells are flat and ciliated and contain glial fibrillary acidic protein (GFAP). After 3-5 days electrically excitable cells appear that contain neuron-specific enolase but not GFAP. These round cells originate by means of the di...

  6. Effect of the hydrophobic basal layer of thermoresponsive block co-polymer brushes on thermally-induced cell sheet harvest.

    Science.gov (United States)

    Matsuzaka, Naoki; Takahashi, Hironobu; Nakayama, Masamichi; Kikuchi, Akihiko; Okano, Teruo

    2012-01-01

    Thermoresponsive poly(benzyl methacrylate)-b-poly(N-isopropylacrylamide) (PBzMA-b-PIPAAm) block co-polymer brush surfaces were prepared by surface-initiated two-step reversible addition-fragmentation chain transfer radical (RAFT) polymerization. PBzMA brushes were fabricated on azoinitiator-immobilized glass substrates in the presence of dithiobenzoate (DTB) compound as a RAFT agent. The amount of grafted polymer was regulated by initial monomer concentrations. The second thermoresponsive blocks were added to the RAFT-related DTB groups located at PBzMA termini through the propagation of PIPAAm chains, resulting in formation of PBzMA-b-PIPAAm brushes. Surface characteristics of the block co-polymer brushes and its influence on thermally regulated cellular behavior were investigated using bovine carotid artery endothelial cells (BAECs), compared with PIPAAm brush surfaces. Cell adhesion/detachment behavior on thermoresponsive polymer brush surfaces significantly depended on their individual polymer architectures and chemical compositions of grafted polymers. Low-temperature treatment at 20°C, below the phase-transition temperature of PIPAAm, induced the spontaneous detachment of adhering cells from the PBzMA-b-PIPAAm brush surfaces with a higher rate than that from PIPAAm brush surfaces. In addition, the cell-repellent effect of the hydrophobic basal layer successfully accelerated for harvesting BAEC sheets from the block co-polymer brush surfaces. Unique features of thermoresponsive block co-polymer brush architectures can be applied to control cell-adhesion strength for enhancing cell adhesion or accelerating cell detachment.

  7. Enhanced casein kinase II activity in human tumour cell cultures

    DEFF Research Database (Denmark)

    Prowald, K; Fischer, H; Issinger, O G

    1984-01-01

    Casein kinase II (CKII) activity is enhanced as much as 2-3 fold in established and 4-5-fold in transformed human cell lines when compared to that of fibroblasts and primary human tumour cell cultures where CKII activity never exceeded a basic level. The high activity of CKII in transformed cells...

  8. Microfluidic bioreactors for culture of non-adherent cells

    DEFF Research Database (Denmark)

    Shah, Pranjul Jaykumar; Vedarethinam, Indumathi; Kwasny, Dorota

    2011-01-01

    Microfluidic bioreactors (μBR) are becoming increasingly popular for cell culture, sample preparation and analysis in case of routine genetic and clinical diagnostics. We present a novel μBR for non-adherent cells designed to mimic in vivo perfusion of cells based on diffusion of media through...

  9. [Cytotoxicity studies on T-3262 in cultured Chinese hamster cells].

    Science.gov (United States)

    Yoneda, T; Nakamura, S; Nojima, Y; Nishio, Y

    1989-04-01

    T-3262 is an antibacterial drug which belongs to the group of pyridonecarboxylic acids. In this study, we investigated cytotoxicity of T-3262 for inhibition of cell growth and effects on viability of, and morphological changes in cultured Chinese hamster cells (V79 cells). The following results were obtained. 1. The 50% inhibition dose of T-3262 for cell growth (ID50, cultured for 48 hours) was 12 micrograms/ml, showing that the inhibitory effect of T-3262 on the cell growth was stronger than that of enoxacin (ENX: ID50 44 micrograms/ml), norfloxacin (NFLX: ID50 105 micrograms/ml) or ofloxacin (OFLX: ID50 145 micrograms/ml). 2. The number of cells increased and dead cells were scarcely seen at the highest concentration tested in culture medium (40 micrograms/ml of T-3262 for 48 hours). At this concentration, degeneration of cytoplasm (atrophy and round shape) and decrease of mitotic cells were observed. These morphological changes were similar to those of the cells treated 400 micrograms/ml of NFLX or OFLX for 48 hours. 3. After the removal of T-3262 from culture medium, the cells began to grow actively and recovered from the morphological changes. The similar phenomenon was observed with ENX treated cells but not with fluorouracil or mitomycin C treated cells.

  10. Application of cell co-culture system to study fat and muscle cells.

    Science.gov (United States)

    Pandurangan, Muthuraman; Hwang, Inho

    2014-09-01

    Animal cell culture is a highly complex process, in which cells are grown under specific conditions. The growth and development of these cells is a highly unnatural process in vitro condition. Cells are removed from animal tissues and artificially cultured in various culture vessels. Vitamins, minerals, and serum growth factors are supplied to maintain cell viability. Obtaining result homogeneity of in vitro and in vivo experiments is rare, because their structure and function are different. Living tissues have highly ordered complex architecture and are three-dimensional (3D) in structure. The interaction between adjacent cell types is quite distinct from the in vitro cell culture, which is usually two-dimensional (2D). Co-culture systems are studied to analyze the interactions between the two different cell types. The muscle and fat co-culture system is useful in addressing several questions related to muscle modeling, muscle degeneration, apoptosis, and muscle regeneration. Co-culture of C2C12 and 3T3-L1 cells could be a useful diagnostic tool to understand the muscle and fat formation in animals. Even though, co-culture systems have certain limitations, they provide a more realistic 3D view and information than the individual cell culture system. It is suggested that co-culture systems are useful in evaluating the intercellular communication and composition of two different cell types.

  11. Establishment of sorghum cell suspension culture system for ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-03-18

    Mar 18, 2008 ... Total soluble proteins (TSP) and culture filtrate (CF) proteins were extracted from the cell culture ... Even though. Arabidopsis provides for an excellent model system for .... stained, destained and imaged using a Molecular Imager PharosFX ... system, are dynamic and heterogeneous, being com- posed of a ...

  12. Expansion of Endothelial Progenitor Cells in High Density Dot Culture of Rat Bone Marrow Cells

    Science.gov (United States)

    Wang, Ling; Kretlow, James D.; Zhou, Guangdong; Cao, Yilin; Liu, Wei; Zhang, Wen Jie

    2014-01-01

    In vitro expansion of endothelial progenitor cells (EPCs) remains a challenge in stem cell research and its application. We hypothesize that high density culture is able to expand EPCs from bone marrow by mimicking cell-cell interactions of the bone marrow niche. To test the hypothesis, rat bone marrow cells were either cultured in high density (2×105 cells/cm2) by seeding total 9×105 cells into six high density dots or cultured in regular density (1.6×104 cells/cm2) with the same total number of cells. Flow cytometric analyses of the cells cultured for 15 days showed that high density cells exhibited smaller cell size and higher levels of marker expression related to EPCs when compared to regular density cultured cells. Functionally, these cells exhibited strong angiogenic potentials with better tubal formation in vitro and potent rescue of mouse ischemic limbs in vivo with their integration into neo-capillary structure. Global gene chip and ELISA analyses revealed up-regulated gene expression of adhesion molecules and enhanced protein release of pro-angiogenic growth factors in high density cultured cells. In summary, high density cell culture promotes expansion of bone marrow contained EPCs that are able to enhance tissue angiogenesis via paracrine growth factors and direct differentiation into endothelial cells. PMID:25254487

  13. Feeding lactate for CHO cell culture processes: impact on culture metabolism and performance.

    Science.gov (United States)

    Li, Jincai; Wong, Chun Loong; Vijayasankaran, Natarajan; Hudson, Terry; Amanullah, Ashraf

    2012-05-01

    Lactate has long been regarded as one of the key metabolites of mammalian cell cultures. High levels of lactate have clear negative impacts on cell culture processes, and therefore, a great amount of efforts have been made to reduce lactate accumulation and/or to induce lactate consumption in the later stage of cultures. However, there is virtually no report on the impact of lactate depletion after initial accumulation. In this work, we observed that glucose uptake rate dropped over 50% at the onset of lactate consumption, and that catabolism of alanine due to lactate depletion led to ammonium accumulation. We explored the impact of feeding lactate as well as pyruvate to the cultures. In particular, a strategy was employed where CO(2) was replaced by lactic acid for culture pH control, which enabled automatic lactate feeding. The results demonstrated that lactate or pyruvate can serve as an alternative or even preferred carbon source during certain stage of the culture in the presence of glucose, and that by feeding lactate or pyruvate, very low levels of ammonia can be achieved throughout the culture. In addition, low levels of pCO(2) were also maintained in these cultures. This was in strong contrast to the control cultures where lactate was depleted during the culture, and ammonia and pCO(2) build-up were significant. Culture growth and productivity were similar between the control and lactate-fed cultures, as well as various product quality attributes. To our knowledge, this work represents the first comprehensive study on lactate depletion and offers a simple yet effective strategy to overcome ammonia and pCO(2) accumulation that could arise in certain cultures due to early depletion of lactate.

  14. Adherence of Moraxella bovis to cell cultures of bovine origin.

    Science.gov (United States)

    Annuar, B O; Wilcox, G E

    1985-09-01

    The adherence of five strains of Moraxella bovis to cell cultures was investigated. M bovis adhered to cultures of bovine corneal epithelial and Madin-Darby bovine kidney cells but not to cell types of non-bovine origin. Both piliated and unpiliated strains adhered but piliated strains adhered to a greater extent than unpiliated strains. Antiserum against pili of one strain inhibited adherence of piliated strains but caused only slight inhibition of adherence to the unpiliated strains. Treatment of bacteria with magnesium chloride caused detachment of pili from the bacterial cell and markedly inhibited adherence of piliated strains but caused only slight inhibition of adherence by the unpiliated strains. The results suggested that adhesion of piliated strains to cell cultures was mediated via pili but that adhesins other than pili may be involved in the attachment of unpiliated strains of M bovis to cells.

  15. Quantitative volumetric Raman imaging of three dimensional cell cultures

    KAUST Repository

    Kallepitis, Charalambos

    2017-03-22

    The ability to simultaneously image multiple biomolecules in biologically relevant three-dimensional (3D) cell culture environments would contribute greatly to the understanding of complex cellular mechanisms and cell–material interactions. Here, we present a computational framework for label-free quantitative volumetric Raman imaging (qVRI). We apply qVRI to a selection of biological systems: human pluripotent stem cells with their cardiac derivatives, monocytes and monocyte-derived macrophages in conventional cell culture systems and mesenchymal stem cells inside biomimetic hydrogels that supplied a 3D cell culture environment. We demonstrate visualization and quantification of fine details in cell shape, cytoplasm, nucleus, lipid bodies and cytoskeletal structures in 3D with unprecedented biomolecular specificity for vibrational microspectroscopy.

  16. Mixed cultures of Kimchi lactic acid bacteria show increased cell ...

    African Journals Online (AJOL)

    ufuoma

    kimchi lactobacilli on batch fermentation increased the cell density and lactic acid production with low nutrients .... first series of fermentations were carried out using pure cultures of each ... Each number represents the mean. ± SD of three ...

  17. Cell/Tissue Culture Radiation Exposure Facility Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a Cell/Tissue Culture Radiation Exposure Facility (CTC-REF) to enable radiobiologists to investigate the real-time radiation effects on...

  18. Bifunctional Polymer Nanocomposites as Hole-Transport Layers for Efficient Light Harvesting: Application to Perovskite Solar Cells.

    Science.gov (United States)

    Wang, Jhong-Yao; Hsu, Fang-Chi; Huang, Jeng-Yeh; Wang, Leeyih; Chen, Yang-Fang

    2015-12-23

    A new approach to largely enhancing light harvesting of solar cells by employing bifunctional polymer nanocomposites as hole-transport layers (HTLs) is proposed. To illustrate our working principle, CH3NH3PbI3-xClx perovskite solar cells are used as examples. Gold nanoparticles (Au-NPs) are added into a conjugated poly(3-hexylthiophene-2,5-diyl) (P3HT) matrix, resulting in a ∼4-fold enhancement in the electrical conductivity and carrier mobility of the native P3HT film. The improved electrical properties are attributed to enhanced polymer chain ordering caused by Au-NPs. By integration of those P3HT:Au-NP films with an optimum loading concentration of 20% into perovskite solar cells as HTLs, this leads to a more than 25% enhancement in the power conversion efficiency (PCE) compared with that of the NP-free one. In addition to the modulated electrical properties of the HTL, the improved performance can also be attributed to the scattering effect from the incorporated Au-NPs, which effectively extends the optical pathway to amplify photon absorption of the photoactive layer. The design principle shown here can be generalized to other organic materials as well, which should be very useful for the further development of high-performance optoelectronic devices.

  19. Upright nanopyramid structured cover glass with light harvesting and self-cleaning effects for solar cell applications

    Science.gov (United States)

    Amalathas, Amalraj Peter; Alkaisi, Maan M.

    2016-11-01

    In this paper, we demonstrate the effect of upright nanopyramid (UNP) structured cover glass with light harvesting and self-cleaning functions on the device performance of monocrystalline Si solar cells. The UNP structures were fabricated on the surface of the glass substrate by simple, high throughput and low cost UV nanoimprint lithography, using a Si master mold with inverted nanopyramid (INP) structures. The diffuse transmittance and haze ratio values were significantly increased for UNP patterned glass, especially in the wavelength range 300-600 nm compared to the bare glass; this implies that antireflection and strong light scattering are due to the UNP structures. By replacing a bare cover glass with UNP patterned glass, the power conversion efficiency of the monocrystalline Si solar cell was substantially enhanced by about 10.97%; this is mainly due to the increased short-circuit current density J SC of 32.39 mA cm-2 compared to the reference cell with bare cover glass (i.e. J SC  =  31.60 mA cm-2). In addition, unlike the bare cover glass (i.e. θ CA ~ 36°), the fluorinated UNP structured cover glass exhibited a hydrophobic surface with a water contact angle (θ CA) of ~132° and excellent self-cleaning of dust particles by rolling down water droplets.

  20. A stack-based flex-compressive piezoelectric energy harvesting cell for large quasi-static loads

    Science.gov (United States)

    Wang, Xianfeng; Shi, Zhifei; Wang, Jianjun; Xiang, Hongjun

    2016-05-01

    In this paper, a flex-compressive piezoelectric energy harvesting cell (F-C PEHC) is proposed. This cell has a large load capacity and adjustable force transmission coefficient assembled from replaceable individual components. A statically indeterminate mechanical model for the cell is established and the theoretical force transmission coefficient is derived based on structural mechanics. An inverse correlation between the force transmission coefficient and the relative stiffness of Element 1’s limbs is found. An experimental study is also conducted to verify the theoretical results. Both weakened and enhanced modes are achieved for this experiment. The maximum power output approaches 4.5 mW at 120 kΩ resistive load under a 4 Hz harmonic excitation with 600 N amplitude for the weakened mode, whereas the maximum power output approaches 17.8 mW at 120 kΩ under corresponding load for the enhanced mode. The experimental measurements of output voltages are compared with the theoretical ones in both weakened and enhanced modes. The experimental measurements of open-circuit voltages are slightly smaller for harmonic excitations with amplitudes that vary from 400 N to 800 N and the errors are within 14%. During the experiment, the maximum load approaches 2.8 kN which is quite large but not the ultimate bearing capacity of the present device. The mechanical model and theoretical transmission coefficient can be used in other flex-compressive mode energy transducers.

  1. “Seren Taun” between hegemony and culture industry; Reading a Sundanese ritual of harvest in Cigugur, West Java

    Directory of Open Access Journals (Sweden)

    Lilawati Kurnia

    2015-07-01

    Full Text Available Seren Taun is a ritual ceremony and celebration, which is practiced in West Java by the Sundanese. It is similar to Thanksgiving in many countries. The village Cigugur, located 3 km west of Kuningan, is the focus of the paper, because the Seren Taun celebration there has been a major event and received a lot of attention from the media, government, and scholars. Many non-Javanese traditional celebrations were repressed during the Suharto era and traditional beliefs were either also repressed or co-opted into one of the five official religions. During the post-Suharto era, the spirit of reformation has brought diversity of more than 300 ethnic groups onto the surface. With the aim to preserve and maintain the tradition of Seren Taun, but as well as to preserve the identity and collective memory of the community, Djatikusumah, chairman of PACKU, has in these recent years developed several policies, concerning traditional art performances, buildings/sites used for ceremonies, and the batik motives that were taken from woodcarvings in the Paseban hall. This paper will explore the intersection between the role of Djatikusumah as an agency and the culture industry he invented.

  2. Isolation, Culture and Identification of Porcine Skeletal Muscle Satellite Cells

    Directory of Open Access Journals (Sweden)

    Bo-jiang Li

    2015-08-01

    Full Text Available The objective of this study was to establish the optimum protocol for the isolation and culture of porcine muscle satellite cells. Mononuclear muscle satellite cells are a kind of adult stem cell, which is located between the basal lamina and sarcolemma of muscle fibers and is the primary source of myogenic precursor cells in postnatal muscle. Muscle satellite cells are a useful model to investigate the mechanisms of muscle growth and development. Although the isolation and culture protocols of muscle satellite cells in some species (e.g. mouse have been established successfully, the culture system for porcine muscle satellite cells is very limited. In this study, we optimized the isolation procedure of porcine muscle satellite cells and elaborated the isolation and culture process in detail. Furthermore, we characterized the porcine muscle satellite cells using the immunofluorecence. Our study provides a reference for the isolation of porcine muscle satellite cells and will be useful for studying the molecular mechanisms in these cells.

  3. Co-cultivation of fungal and microalgal cells as an efficient system for harvesting microalgal cells, lipid production and wastewater treatment.

    Science.gov (United States)

    Wrede, Digby; Taha, Mohamed; Miranda, Ana F; Kadali, Krishna; Stevenson, Trevor; Ball, Andrew S; Mouradov, Aidyn

    2014-01-01

    The challenges which the large scale microalgal industry is facing are associated with the high cost of key operations such as harvesting, nutrient supply and oil extraction. The high-energy input for harvesting makes current commercial microalgal biodiesel production economically unfeasible and can account for up to 50% of the total cost of biofuel production. Co-cultivation of fungal and microalgal cells is getting increasing attention because of high efficiency of bio-flocculation of microalgal cells with no requirement for added chemicals and low energy inputs. Moreover, some fungal and microalgal strains are well known for their exceptional ability to purify wastewater, generating biomass that represents a renewable and sustainable feedstock for biofuel production. We have screened the flocculation efficiency of the filamentous fungus A. fumigatus against 11 microalgae representing freshwater, marine, small (5 µm), large (over 300 µm), heterotrophic, photoautotrophic, motile and non-motile strains. Some of the strains are commercially used for biofuel production. Lipid production and composition were analysed in fungal-algal pellets grown on media containing alternative carbon, nitrogen and phosphorus sources contained in wheat straw and swine wastewater, respectively. Co-cultivation of algae and A. fumigatus cells showed additive and synergistic effects on biomass production, lipid yield and wastewater bioremediation efficiency. Analysis of fungal-algal pellet's fatty acids composition suggested that it can be tailored and optimised through co-cultivating different algae and fungi without the need for genetic modification.

  4. Co-cultivation of fungal and microalgal cells as an efficient system for harvesting microalgal cells, lipid production and wastewater treatment.

    Directory of Open Access Journals (Sweden)

    Digby Wrede

    Full Text Available The challenges which the large scale microalgal industry is facing are associated with the high cost of key operations such as harvesting, nutrient supply and oil extraction. The high-energy input for harvesting makes current commercial microalgal biodiesel production economically unfeasible and can account for up to 50% of the total cost of biofuel production. Co-cultivation of fungal and microalgal cells is getting increasing attention because of high efficiency of bio-flocculation of microalgal cells with no requirement for added chemicals and low energy inputs. Moreover, some fungal and microalgal strains are well known for their exceptional ability to purify wastewater, generating biomass that represents a renewable and sustainable feedstock for biofuel production. We have screened the flocculation efficiency of the filamentous fungus A. fumigatus against 11 microalgae representing freshwater, marine, small (5 µm, large (over 300 µm, heterotrophic, photoautotrophic, motile and non-motile strains. Some of the strains are commercially used for biofuel production. Lipid production and composition were analysed in fungal-algal pellets grown on media containing alternative carbon, nitrogen and phosphorus sources contained in wheat straw and swine wastewater, respectively. Co-cultivation of algae and A. fumigatus cells showed additive and synergistic effects on biomass production, lipid yield and wastewater bioremediation efficiency. Analysis of fungal-algal pellet's fatty acids composition suggested that it can be tailored and optimised through co-cultivating different algae and fungi without the need for genetic modification.

  5. Co-Cultivation of Fungal and Microalgal Cells as an Efficient System for Harvesting Microalgal Cells, Lipid Production and Wastewater Treatment

    Science.gov (United States)

    Wrede, Digby; Taha, Mohamed; Miranda, Ana F.; Kadali, Krishna; Stevenson, Trevor; Ball, Andrew S.; Mouradov, Aidyn

    2014-01-01

    The challenges which the large scale microalgal industry is facing are associated with the high cost of key operations such as harvesting, nutrient supply and oil extraction. The high-energy input for harvesting makes current commercial microalgal biodiesel production economically unfeasible and can account for up to 50% of the total cost of biofuel production. Co-cultivation of fungal and microalgal cells is getting increasing attention because of high efficiency of bio-flocculation of microalgal cells with no requirement for added chemicals and low energy inputs. Moreover, some fungal and microalgal strains are well known for their exceptional ability to purify wastewater, generating biomass that represents a renewable and sustainable feedstock for biofuel production. We have screened the flocculation efficiency of the filamentous fungus A. fumigatus against 11 microalgae representing freshwater, marine, small (5 µm), large (over 300 µm), heterotrophic, photoautotrophic, motile and non-motile strains. Some of the strains are commercially used for biofuel production. Lipid production and composition were analysed in fungal-algal pellets grown on media containing alternative carbon, nitrogen and phosphorus sources contained in wheat straw and swine wastewater, respectively. Co-cultivation of algae and A. fumigatus cells showed additive and synergistic effects on biomass production, lipid yield and wastewater bioremediation efficiency. Analysis of fungal-algal pellet's fatty acids composition suggested that it can be tailored and optimised through co-cultivating different algae and fungi without the need for genetic modification. PMID:25419574

  6. Development of Biologically Modified Anodes for Energy Harvesting Using Microbial Fuel Cells

    Science.gov (United States)

    2012-09-01

    media and mediators. The media for Shewanella can be either LB broth , fresh M9 with lactate added as the fuel or spent M9 from yeast cultures. The...include: Inexpensive electrodes, catalysts, scale-up designs, field tests, electron transfer mechanisms, fermentation control, designed consortia...Current Generation and Cellulose Fermentation in a Microbial Fuel Cell”, Applied Microbiology and Biotechnology 76(3), 561- 568 (2007). [9] Lowy, D.A

  7. Culture of Iris Pigment Epithelial Cells on Expanded-Polytetrafluroethylene (ePTFE Substrates for the Treatment of Age-Related Macular Degeneration

    Directory of Open Access Journals (Sweden)

    S Nian

    2011-05-01

    Full Text Available Introduction: Transplantation of an intact differentiated retinal pigment epithelial (RPE cell layer may provide a means to treat Age-Related Macular Degeneration (AMD. However, harvesting RPE cells can be a technically complicated procedure. Our current work aimed to prepare intact differentiated iris pigment epithelial (IPE cell layers, which are easy to obtain and have the same embryonic origin and similar properties as RPE cells, on ePTFE substrates for transplantation purposes to rescue deteriorated photoreceptors in AMD. Methods: IPE cells isolated from rat eyes were seeded on different substrates, including fibronectin n-heptylamine (HA ePTFE substrates, HA ePTFE substrates, ePTFE substrates and fibronectin tissue culture polystyrene (TCPS as control. Cell number and morphology were assessed at each time interval. The formation of tight junction was examined by immunostaining of junction proteins. Results: An obvious increasing trend of cell number was observed in IPE cells on fibronectin n-heptylamine (HA ePTFE substrate, exhibiting heavy pigmentation and epithelial morphology. At Day 28, tight junction formation was indicated by cell-cell junctional proteins along cell borders. Conclusion: Harvested IPE cells cultured on fibronectin HA-ePTFE substrates can differentiate and form a cell monolayer that may be suitable for transplantation.

  8. Pharmacodynamic modeling of anti-cancer activity of tetraiodothyroacetic acid in a perfused cell culture system.

    Directory of Open Access Journals (Sweden)

    Hung-Yun Lin

    Full Text Available Unmodified or as a poly[lactide-co-glycolide] nanoparticle, tetraiodothyroacetic acid (tetrac acts at the integrin αvβ3 receptor on human cancer cells to inhibit tumor cell proliferation and xenograft growth. To study in vitro the pharmacodynamics of tetrac formulations in the absence of and in conjunction with other chemotherapeutic agents, we developed a perfusion bellows cell culture system. Cells were grown on polymer flakes and exposed to various concentrations of tetrac, nano-tetrac, resveratrol, cetuximab, or a combination for up to 18 days. Cells were harvested and counted every one or two days. Both NONMEM VI and the exact Monte Carlo parametric expectation maximization algorithm in S-ADAPT were utilized for mathematical modeling. Unmodified tetrac inhibited the proliferation of cancer cells and did so with differing potency in different cell lines. The developed mechanism-based model included two effects of tetrac on different parts of the cell cycle which could be distinguished. For human breast cancer cells, modeling suggested a higher sensitivity (lower IC50 to the effect on success rate of replication than the effect on rate of growth, whereas the capacity (Imax was larger for the effect on growth rate. Nanoparticulate tetrac (nano-tetrac, which does not enter into cells, had a higher potency and a larger anti-proliferative effect than unmodified tetrac. Fluorescence-activated cell sorting analysis of harvested cells revealed tetrac and nano-tetrac induced concentration-dependent apoptosis that was correlated with expression of pro-apoptotic proteins, such as p53, p21, PIG3 and BAD for nano-tetrac, while unmodified tetrac showed a different profile. Approximately additive anti-proliferative effects were found for the combinations of tetrac and resveratrol, tetrac and cetuximab (Erbitux, and nano-tetrac and cetuximab. Our in vitro perfusion cancer cell system together with mathematical modeling successfully described the anti

  9. Time related variations in stem cell harvesting of umbilical cord blood

    Science.gov (United States)

    Mazzoccoli, Gianluigi; Miscio, Giuseppe; Fontana, Andrea; Copetti, Massimiliano; Francavilla, Massimo; Bosi, Alberto; Perfetto, Federico; Valoriani, Alice; De Cata, Angelo; Santodirocco, Michele; Totaro, Angela; Rubino, Rosa; di Mauro, Lazzaro; Tarquini, Roberto

    2016-01-01

    Umbilical cord blood (UCB) contains hematopoietic stem cells and multipotent mesenchymal cells useful for treatment in malignant/nonmalignant hematologic-immunologic diseases and regenerative medicine. Transplantation outcome is correlated with cord blood volume (CBV), number of total nucleated cells (TNC), CD34+ progenitor cells and colony forming units in UCB donations. Several studies have addressed the role of maternal/neonatal factors associated with the hematopoietic reconstruction potential of UCB, including: gestational age, maternal parity, newborn sex and birth weight, placental weight, labor duration and mode of delivery. Few data exist regarding as to how time influences UCB collection and banking patterns. We retrospectively analyzed 17.936 cord blood donations collected from 1999 to 2011 from Tuscany and Apulia Cord Blood Banks. Results from generalized multivariable linear mixed models showed that CBV, TNC and CD34+ cell were associated with known obstetric and neonatal parameters and showed rhythmic patterns in different time domains and frequency ranges. The present findings confirm that volume, total nucleated cells and stem cells of the UCB donations are hallmarked by rhythmic patterns in different time domains and frequency ranges and suggest that temporal rhythms in addition to known obstetric and neonatal parameters influence CBV, TNC and CD34+ cell content in UBC units. PMID:26906327

  10. Human hematopoietic cell culture, transduction, and analyses

    DEFF Research Database (Denmark)

    Bonde, Jesper; Wirthlin, Louisa; Kohn, Donald B;

    2008-01-01

    This unit provides methods for introducing genes into human hematopoietic progenitor cells. The Basic Protocol describes isolation of CD34(+) cells, transduction of these cells with a retroviral vector on fibronectin-coated plates, assaying the efficiency of transduction, and establishing long...

  11. Generation of a patterned co-culture system composed of adherent cells and immobilized nonadherent cells.

    Science.gov (United States)

    Yamazoe, Hironori; Ichikawa, Takashi; Hagihara, Yoshihisa; Iwasaki, Yasuhiko

    2016-02-01

    Patterned co-culture is a promising technique used for fundamental investigation of cell-cell communication and tissue engineering approaches. However, conventional methods are inapplicable to nonadherent cells. In this study, we aimed to establish a patterned co-culture system composed of adherent and nonadherent cells. Nonadherent cells were immobilized on a substrate using a cell membrane anchoring reagent conjugated to a protein, in order to incorporate them into the co-culture system. Cross-linked albumin film, which has unique surface properties capable of regulating protein adsorption, was used to control their spatial localization. The utility of our approach was demonstrated through the fabrication of a patterned co-culture consisting of micropatterned neuroblastoma cells surrounded by immobilized myeloid cells. Furthermore, we also created a co-culture system composed of cancer cells and immobilized monocytes. We observed that monocytes enhanced the drug sensitivity of cancer cells and its influence was limited to cancer cells located near the monocytes. Therefore, the incorporation of nonadherent cells into a patterned co-culture system is useful for creating culture systems containing immune cells, as well as investigating the influence of these immune cells on cancer drug sensitivity. Various methods have been proposed for creating patterned co-culture systems, in which multiple cell types are attached to a substrate with a desired pattern. However, conventional methods, including our previous report published in Acta Biomaterialia (2010, 6, 526-533), are unsuitable for nonadherent cells. Here, we developed a novel method that incorporates nonadherent cells into the co-culture system, which allows us to precisely manipulate and study microenvironments containing nonadherent and adherent cells. Using this technique, we demonstrated that monocytes (nonadherent cells) could enhance the drug sensitivity of cancer cells and that their influence had a

  12. Which form of collagen is suitable for nerve cell culture?*

    Institute of Scientific and Technical Information of China (English)

    Mohsen Fathi Najafi; Saber Zahri; Fatemeh Vahedi; Leila Esmaililian Toosi; Nazila Ariaee

    2013-01-01

    In this study, we investigated the effects of hydrolyzed and non-hydrolyzed col agen and two-dimensional and three-dimensional col agen matrices on cell survival, attachment and neurite outgrowth of primary cultured nerve cells using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay and inverted microscopy. Hydrolyzed col agen facilitated nerve cell survival and neurite outgrowth, but it had no obvious influences on cellattachment. In contrast, non-hydrolyzed two-dimensional collagen matrix had no obvious effects on neurite outgrowth. These findings suggest that hydrolyzed col agen is an ideal nerve cell culture media.

  13. Study on Cell Suspension Culture of Floribunda Rose

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chun'ai; WANG Jingang; FAN Jinping; GONG Shufang; CHE Daidi

    2008-01-01

    Friable callus was induced when immature seeds of floribunda rose were inoculated on MS medium supplemented with 2,4-D 3.0 mg-L-1.When transfered onto subculture media,fi-iable callus developed into embryogenic callus,which was used to establish cell suspension lines.Cell suspensions had to be subcultured at a interval of 4-5 days at the first several culture cycles.The best subculturing cycle for the stable cell suspensions was 8-10 days.The best inoculum quantity was 1 mL PCV(Packed Cell Volume) per 40 mL culture fluid.

  14. 2D- and 3D-culture of cell

    Directory of Open Access Journals (Sweden)

    Khoruzhenko A. I.

    2011-02-01

    Full Text Available The cultivation of mammalian cells in three-dimensional conditions acquires a priority in a variety of biomedical applications. In the areas of toxicology and anticancer drug development it concerns a significant difference of responses to proapoptotic factors of the cells cultured in 2D versus 3D environment. Besides, the clear-cut differences have been found in cell polarity, cytoskeleton structure, distribution of receptors to wide range of hormones, growth factors, etc. in mammalian cells depending on culture conditions. It is resulted in different response of cultured cells to extracellular stimuli. Multicellular spheroids are regarded presently as the most convenient model of solid tumour growth in vitro. The cultivation of thyroid follicles, mammary acini and other structure units, maintaining initial tissue organization, allows studying the behavior, biochemical features and gene profile of differentiated cells. On the other hand, 3D cultures have some limitations in comparison with a well established monolayer culture. The advantages and disadvantages of each type of cultures and their application in biological and medical researches will be discussed in this review

  15. Effect of phenylalanine on Taxol production and antioxidant activity of extracts of suspension-cultured hazel (Corylus avellana L.) cells.

    Science.gov (United States)

    Bemani, Ebrahim; Ghanati, Faezeh; Rezaei, Ayatollah; Jamshidi, Mitra

    2013-07-01

    Taxol is produced by a few microorganisms and plants such as yew (Taxus sp.). Recent researches have shown that hazel (Corylus avellana L.) is also able to produce Taxol. In the present study, effects of different concentrations of phenylalanine (Phe) on the production of Taxol, antioxidant activity, and cytotoxic effects of extracts of suspension-cultured hazel cells were investigated. The cells were treated with different concentrations of Phe on day 7 of subculture and were harvested on day 14. The results showed that the amounts of Taxol and antioxidant activity were increased by increasing the phenylalanine supply. Interestingly, the cytotoxic effects of hazel cell extract were even stronger than that of pure Taxol (standard), suggesting hazel cell extract as a novel and suitable probe for treating human cancer. Application of phenylalanine to hazel cells exaggerates their effects.

  16. Convoluted cells as a marker for maternal cell contamination in CVS cultures

    DEFF Research Database (Denmark)

    Hertz, Jens Michael; Jensen, P K; Therkelsen, A J

    1987-01-01

    In order to identify cells of maternal origin in CVS cultures, tissue from 1st trimester abortions were cultivated and the cultures stained in situ for X-chromatin. Convoluted cells and maternal fibroblasts were found to be positive. By chromosome analysis of cultures from 105 diagnostic placenta...... biopsies, obtained by the transabdominal route, metaphases of maternal origin were found in nine cases. In eight of these cases colonies of convoluted cells were observed. We conclude that convoluted cells are of maternal origin and are a reliable marker for maternal cell contamination in CVS cultures....

  17. Systematic microcarrier screening and agitated culture conditions improves human mesenchymal stem cell yield in bioreactors.

    Science.gov (United States)

    Rafiq, Qasim A; Coopman, Karen; Nienow, Alvin W; Hewitt, Christopher J

    2016-03-01

    Production of human mesenchymal stem cells for allogeneic cell therapies requires scalable, cost-effective manufacturing processes. Microcarriers enable the culture of anchorage-dependent cells in stirred-tank bioreactors. However, no robust, transferable methodology for microcarrier selection exists, with studies providing little or no reason explaining why a microcarrier was employed. We systematically evaluated 13 microcarriers for human bone marrow-derived MSC (hBM-MSCs) expansion from three donors to establish a reproducible and transferable methodology for microcarrier selection. Monolayer studies demonstrated input cell line variability with respect to growth kinetics and metabolite flux. HBM-MSC1 underwent more cumulative population doublings over three passages in comparison to hBM-MSC2 and hBM-MSC3. In 100 mL spinner flasks, agitated conditions were significantly better than static conditions, irrespective of donor, and relative microcarrier performance was identical where the same microcarriers outperformed others with respect to growth kinetics and metabolite flux. Relative growth kinetics between donor cells on the microcarriers were the same as the monolayer study. Plastic microcarriers were selected as the optimal microcarrier for hBM-MSC expansion. HBM-MSCs were successfully harvested and characterised, demonstrating hBM-MSC immunophenotype and differentiation capacity. This approach provides a systematic method for microcarrier selection, and the findings identify potentially significant bioprocessing implications for microcarrier-based allogeneic cell therapy manufacture.

  18. Xeno-free culture of human periodontal ligament stem cells.

    Science.gov (United States)

    Trubiani, Oriana; Diomede, Francesca

    2015-01-01

    The possibility of transplanting adult stem cells into damaged organs has opened a new prospective for the treatment of several human pathologies. Currently, in vitro expansion and culture of mesenchymal stem cells is founded on supplementing cell culture and differentiation medium with fetal calf serum (FCS) or fetal bovine serum (FBS) that contain numerous growth factors inducing cell attachment to plastic surfaces, proliferation, and differentiation. Mesenchymal stem cells (MSCs) cultured with medium containing FCS or FBS are unusable in the cell therapy; in fact the central issues regarding limitations in using animal sera for cell therapy is that its components are highly variable and often unknown and may trigger a xenogenic immune response, immunological reactions, and the potential transmission of prion diseases and zoonoses. Here we describe the culture system protocols for the expansion and production of human Periodontal Ligament Stem Cells (hPDLSCs) using a new xeno-free medium formulation ensuring the maintenance of the stem cells features comprising the multiple passage expansion, mesengenic lineage differentiation, cellular phenotype, and genomic stability, essential elements for conforming to translation to cell therapy.

  19. Guard cell protoplasts: isolation, culture, and regeneration of plants.

    Science.gov (United States)

    Tallman, Gary

    2006-01-01

    Guard cell protoplasts have been used extensively in short-term experiments designed to elucidate the signal transduction mechanisms that regulate stomatal movements. The utility of uard cell protoplasts for other types of longer-term signal transduction experiments is just now being realized. Because highly purified, primary isolates of guard cell protoplasts are synchronous initially, they are uniform in their responses to changes in culture conditions. Such isolates have demonstrated potential to reveal mechanisms that underlie hormonal signalling for plant cell survival, cell cycle re-entry, reprogramming of genes during dedifferentiation to an embryogenic state, and plant cell thermotolerance. Plants have been regenerated from cultured guard cell protoplasts of two species: Nicotiana glauca (Graham), tree tobacco, and Beta vulgaris, sugar beet. Plants genetically engineered for herbicide tolerance have been regenerated from cultured guard cell protoplasts of B. vulgaris. The method for isolating, culturing, and regenerating plants from guard cell protoplasts of N. glauca is described here. A recently developed procedure for large-scale isolation of these cells from as many as nine leaves per experiment is described. Using this protocol, yields of 1.5-2 x 10(7) per isolate may be obtained. Such yields are sufficient for standard methods of molecular, biochemical, and proteomic analysis.

  20. Auxin requirements of sycamore cells in suspension culture.

    Science.gov (United States)

    Moloney, M M; Hall, J F; Robinson, G M; Elliott, M C

    1983-04-01

    Sycamore (Acer pseudoplatanus L.) cell suspension cultures (strain OS) require 2,4-dichlorophenoxyacetic acid (2,4-D) in their culture medium for normal growth. If the 2,4-D is omitted, rates of cell division are dramatically reduced and cell lysis may occur. Despite this ;auxin requirement,' it has been shown by gas chromatography-mass spectrometry that the cells synthesize indol-3yl-acetic acid (IAA). Changes in free 2,4-D and IAA in the cells during a culture passage have been monitored.There is a rapid uptake of 2,4-D by the cells during the lag phase leading to a maximum concentration per cell (125 nanograms per 10(6) cells) on day 2 followed by a decline to 45 nanograms per 10(6) cells by day 9 (middle of linear phase). The initial concentration of IAA (0.08 nanograms per 10(6) cells) rises slowly to a peak of 1.4 nanograms per 10(6) cells by day 9 then decreases rapidly to 0.2 nanograms per 10(6) cells by day 15 (early declining phase) and 0.08 nanograms per 10(6) cells by day 23 (early stationary phase).

  1. Isolation and Culture of Satellite Cells from Mouse Skeletal Muscle.

    Science.gov (United States)

    Musarò, Antonio; Carosio, Silvia

    2017-01-01

    Skeletal muscle tissue is characterized by a population of quiescent mononucleated myoblasts, localized between the basal lamina and sarcolemma of myofibers, known as satellite cells. Satellite cells play a pivotal role in muscle homeostasis and are the major source of myogenic precursors in mammalian muscle regeneration.This chapter describes protocols for isolation and culturing satellite cells isolated from mouse skeletal muscles. The classical procedure, which will be discussed extensively in this chapter, involves the enzymatic dissociation of skeletal muscles, while the alternative method involves isolation of satellite cells from isolated myofibers in which the satellite cells remain in their in situ position underneath the myofiber basal lamina.In particular, we discuss the technical aspect of satellite cell isolation, the methods necessary to enrich the satellite cell fraction and the culture conditions that optimize proliferation and myotube formation of mouse satellite cells.

  2. [Effect evaluation of three cell culture models].

    Science.gov (United States)

    Wang, Aiguo; Xia, Tao; Yuan, Jing; Chen, Xuemin

    2003-11-01

    Primary rat hepatocytes were cultured using three kinds of models in vitro and the enzyme leakage, albumin secretion, and cytochrome P450 1A (CYP 1A) activity were observed. The results showed that the level of LDH in the medium decreased over time in the period of culture. However, on 5 days, LDH showed a significant increase in monolayer culture (MC) while after 8 days LDH was not detected in sandwich culture (SC). The levels of AST and ALT in the medium did not change significantly over the investigated time. The basic CYP 1A activity gradually decreased with time in MC and SC. The decline of CYP 1A in rat hepatocytes was faster in MC than that in SC. This effect was partially reversed by using cytochrome P450 (CYP450) inducers such as omeprazol and 3-methylcholanthrene (3-MC) and the CYP 1A induction was always higher in MC than that in SC. Basic CYP 1A activity in bioreactor was keeped over 2 weeks and the highest albumin production was observed in bioreactor, and next were SC and MC. In conclusion, our results clearly indicated that there have some advantages and disadvantages in each of models in which can address different questions in metabolism of toxicants and drugs.

  3. Qualitative study of three cell culture methods.

    Science.gov (United States)

    Wang, Aiguo; Xia, Tao; Ran, Peng; Chen, Xuemin; Nuessler, Andreas K

    2002-01-01

    Primary rat hepatocytes were cultured using different in vitro models and the enzyme leakage, albumin secretion, and cytochrome P450 1A (CYP 1A) activity were observed. The results showed that the level of LDH was decreased over time in culture. However, on day 5, LDH showed a significant increase in monolayer culture (MC) while after day 8 no LDH was detectable in sandwich culture (SC). The levels of AST and ALT did not change significantly over the investigated time. The CYP 1A activity was gradually decreased in a time-dependent manner in MC and SC. The decline of CYP 1A was faster in MC than in SC. This effect was partially reversed by using cytochrome P450 (CYP450) inducer such as Omeprazol and 3-methylcholanthrene (3-MC) and the CYP 1A induction was always higher in MC than in SC. In bioreactor basic CYP 1A activity was preserved over 2 weeks and the highest albumin production was observed in bioreactor followed by SC and MC. Taken together, it was indicated each investigated model had its advantages and disadvantages. It was also underlined that various in vitro models may address different questions.

  4. Morphology of primary human venous endothelial cell cultures before and after culture medium exchange.

    Science.gov (United States)

    Krüger-Genge, A; Fuhrmann, R; Jung, F; Franke, R P

    2015-01-01

    The evaluation of the interaction of human, venous endothelial cells (HUVEC) with body foreign materials on the cellular level cannot be performed in vivo, but is investigated in vitro under standard culture conditions. To maintain the vitality, proliferation and morphology of HUVEC seeded on body foreign substrates over days, the cell culture medium is usually exchanged every second day. It is well known, that alterations in the microenvironment of cells bear the risk of influencing cell morphology and function. In the current study the influence of cell culture medium exchange on HUVEC cytoskeletal microfilament structure and function was investigated. HUVEC in the third passage were seeded on extracellular matrix (ECM) - which was secreted from bovine corneal endothelial cells on glass- until functional confluence was reached. The experiment started 11 days after HUVEC seeding with an exchange of the cell culture medium followed by a staining of the actin microfilaments with phalloidin-rhodamin 1.5 and 5 minutes after medium exchange. The microfilaments were documented by use of an Olympus microscope (IMT-2) equipped with a UV lamp and online connected to a TV chain (Sony XC 50 ST/monochrome) implying an OPTIMAS - Image analysis system. Prostacyclin was analysed in the cell culture supernatant. 1.5 min after culture medium exchange in the functionally confluent cultures a slight disturbance of the actin microfilament structure with a broadening of the marginal filament band, a partial disconnection of cell-cell contacts and the appearance of intercellular fenestrations were observed. 5 minutes after medium exchange a redevelopment of the slightly disturbed microfilament structure with a condensation and narrowing of the marginal filament band was seen. 12 h later a further consolidation of the microfilament structure occurred. In addition, a perturbation of the cultured HUVEC occurred after cell culture medium exchange. The prostacyclin concentration in the

  5. A Novel Flow-Perfusion Bioreactor Supports 3D Dynamic Cell Culture

    Directory of Open Access Journals (Sweden)

    Alexander M. Sailon

    2009-01-01

    Full Text Available Background. Bone engineering requires thicker three-dimensional constructs than the maximum thickness supported by standard cell-culture techniques (2 mm. A flow-perfusion bioreactor was developed to provide chemotransportation to thick (6 mm scaffolds. Methods. Polyurethane scaffolds, seeded with murine preosteoblasts, were loaded into a novel bioreactor. Control scaffolds remained in static culture. Samples were harvested at days 2, 4, 6, and 8 and analyzed for cellular distribution, viability, metabolic activity, and density at the periphery and core. Results. By day 8, static scaffolds had a periphery cell density of 67%±5.0%, while in the core it was 0.3%±0.3%. Flow-perfused scaffolds demonstrated peripheral cell density of 94%±8.3% and core density of 76%±3.1% at day 8. Conclusions. Flow perfusion provides chemotransportation to thick scaffolds. This system may permit high throughput study of 3D tissues in vitro and enable prefabrication of biological constructs large enough to solve clinical problems.

  6. [Primary culture and functional identification of distal pulmonary artery smooth muscle cells in mice].

    Science.gov (United States)

    Li, M C; Chen, Y Q; Zhang, C T; Jiang, Q; Lu, W J; Wang, J

    2017-02-12

    Objective: To establish a method of isolation and primary culture of mice distal pulmonary artery smooth muscle cells (PASMCs) and identify the functional properties. Methods: PASMCs were harvested from the distal pulmonary artery (PA) tissue of mice by enzymatic digestion of collagenaseⅠand papain; and the growth characteristics were observed under inverted microscope and identified by Immunofluorescence technique. Effects on the intracellular calcium ion concentration of distal PASMCs were detected by Fura-2-AM fluorescent probe tracer under a fluorescence microscope in Krebs solution containing clopiazonic acid (CPA) and nifedipin (Nif). Results: PASMCs density reached approximately to 80% in a typical valley-peak-like shape after 6 days. Cell α-smooth muscle actin (α-SMA) immunofluorescence identified that 95% of the cultured cells were PASMCs. More than 95% PASMCs responded well to calcium-potassium Krebs solution (potassium ion concentration of 60 mmol/L) and showed a rapid increase in basal [Ca(2+) ](i) after 1 minute's perfusion (Δ[Ca(2+) ](i)>50), which demonstrated that the voltage-dependent calcium channels (VDCC) of distal PASMCs were in good function; after the perfusion of calcium Krebs, calcium-free/calcium-Krebs containing CPA and Nif, distal PASMCs showed two typical peaks, indicated the full function of store-operated calcium channel (SOCC) in distal PASMCs. Conclusion: This experiment successfully established a stable and reliable mice distal PASMCs model and the study of pulmonary vascular diseases could benefit from its higher purity and better functional condition.

  7. Lacrimal gland primary acinar cell culture: the role of insulin

    Directory of Open Access Journals (Sweden)

    Leonardo Tannus Malki

    2016-04-01

    Full Text Available ABSTRACT Purpose: The goal of the present study was to establish a protocol for primary culture of lacrimal gland acinar cells (LGACs and to assess the effect of adding insulin to the culture media. Methods: LGACs were isolated and cultured from lacrimal glands of Wistar male rats. The study outcomes included cell number, viability, and peroxidase release over time and in response to three concentrations of insulin (0.5, 5.0, and 50.0 μg/mL. Results: In LGAC primary culture, cells started to form clusters by day 3. There was a time-response pattern of peroxidase release, which rose by day 6, in response to carbachol. Culture viability lasted for 12 days. An insulin concentration of 5.0 μg/mL in the culture medium resulted in higher viability and secretory capacity. Conclusions: The present method simplifies the isolation and culture of LGACs. The data confirmed the relevance of adding insulin to maintain LGACs in culture.

  8. Production of recombinant proteins in suspension-cultured plant cells.

    Science.gov (United States)

    Plasson, Carole; Michel, Rémy; Lienard, David; Saint-Jore-Dupas, Claude; Sourrouille, Christophe; de March, Ghislaine Grenier; Gomord, Véronique

    2009-01-01

    Plants have emerged in the past decade as a suitable alternative to the current production systems for recombinant pharmaceutical proteins and, today their potential for low-cost production of high quality, much safer and biologically active mammalian proteins is largely documented. Among various plant expression systems being explored, genetically modified suspension-cultured plant cells offer a promising system for production of biopharmaceuticals. Indeed, when compared to other plant-based production platforms that have been explored, suspension-cultured plant cells have the advantage of being totally devoid of problems associated with the vagaries of weather, pest, soil and gene flow in the environment. Because of short growth cycles, the timescale needed for the production of recombinant proteins in plant cell culture can be counted in days or weeks after transformation compared to months needed for the production in transgenic plants. Moreover, recovery and purification of recombinant proteins from plant biomass is an expensive and technically challenging business that may amount to 80-94% of the final product cost. One additional advantage of plant cell culture is that the recombinant protein fused with a signal sequence can be expressed and secreted into the culture medium, and therefore recovered and purified in the absence of large quantities of contaminating proteins. Consequently, the downstream processing of proteins extracted from plant cell culture medium is less expensive, which may/does balance the higher costs of fermentation. When needed for clinical use, recombinant proteins are easily produced in suspension-cultured plant cells under certified, controllable and sterile conditions that offer improved safety and provide advantages for good manufacturing practices and regulatory compliance. In this chapter, we present basic protocols for rapid generation of transgenic suspension-cultured cells of Nicotiana tabacum, Oriza sativa and Arabidopis

  9. Exposure to Music Alters Cell Viability and Cell Motility of Human Nonauditory Cells in Culture

    Directory of Open Access Journals (Sweden)

    Nathalia R. Lestard

    2016-01-01

    Full Text Available Although music is part of virtually all cultures in the world, little is known about how it affects us. Since the beginning of this century several studies suggested that the response to music, and to sound in general, is complex and might not be exclusively due to emotion, given that cell types other than auditory hair cells can also directly react to audible sound. The present study was designed to better understand the direct effects of acoustic vibrations, in the form of music, in human cells in culture. Our results suggest that the mechanisms of cell growth arrest and/or cell death induced by acoustic vibrations are similar for auditory and nonauditory cells.

  10. Topological defects control collective dynamics in neural progenitor cell cultures

    Science.gov (United States)

    Kawaguchi, Kyogo; Kageyama, Ryoichiro; Sano, Masaki

    2017-04-01

    Cultured stem cells have become a standard platform not only for regenerative medicine and developmental biology but also for biophysical studies. Yet, the characterization of cultured stem cells at the level of morphology and of the macroscopic patterns resulting from cell-to-cell interactions remains largely qualitative. Here we report on the collective dynamics of cultured murine neural progenitor cells (NPCs), which are multipotent stem cells that give rise to cells in the central nervous system. At low densities, NPCs moved randomly in an amoeba-like fashion. However, NPCs at high density elongated and aligned their shapes with one another, gliding at relatively high velocities. Although the direction of motion of individual cells reversed stochastically along the axes of alignment, the cells were capable of forming an aligned pattern up to length scales similar to that of the migratory stream observed in the adult brain. The two-dimensional order of alignment within the culture showed a liquid-crystalline pattern containing interspersed topological defects with winding numbers of +1/2 and -1/2 (half-integer due to the nematic feature that arises from the head-tail symmetry of cell-to-cell interaction). We identified rapid cell accumulation at +1/2 defects and the formation of three-dimensional mounds. Imaging at the single-cell level around the defects allowed us to quantify the velocity field and the evolving cell density; cells not only concentrate at +1/2 defects, but also escape from -1/2 defects. We propose a generic mechanism for the instability in cell density around the defects that arises from the interplay between the anisotropic friction and the active force field.

  11. Dynamic 3D cell culture via a chemoselective photoactuated ligand.

    Science.gov (United States)

    Westcott, Nathan P; Luo, Wei; Goldstein, Jeffrey; Yousaf, Muhammad N

    2014-09-01

    A new strategy to create a dynamic scaffold for three-dimensional (3D) cell experiments based on a photo-activated cell adhesive peptide ligand is described. After polymerization, the inert matrix becomes cell adhesive by chemoselective modification through the conjugation of oxyamine-terminated ligands. Furthermore, spatial and temporal control of cell culture within the 3D matrix was achieved by the use of a biospecific photoprotected peptide and visualized by confocal microscopy.

  12. Hydrofocusing Bioreactor for Three-Dimensional Cell Culture

    Science.gov (United States)

    Gonda, Steve R.; Spaulding, Glenn F.; Tsao, Yow-Min D.; Flechsig, Scott; Jones, Leslie; Soehnge, Holly

    2003-01-01

    The hydrodynamic focusing bioreactor (HFB) is a bioreactor system designed for three-dimensional cell culture and tissue-engineering investigations on orbiting spacecraft and in laboratories on Earth. The HFB offers a unique hydrofocusing capability that enables the creation of a low-shear culture environment simultaneously with the "herding" of suspended cells, tissue assemblies, and air bubbles. Under development for use in the Biotechnology Facility on the International Space Station, the HFB has successfully grown large three-dimensional, tissuelike assemblies from anchorage-dependent cells and grown suspension hybridoma cells to high densities. The HFB, based on the principle of hydrodynamic focusing, provides the capability to control the movement of air bubbles and removes them from the bioreactor without degrading the low-shear culture environment or the suspended three-dimensional tissue assemblies. The HFB also provides unparalleled control over the locations of cells and tissues within its bioreactor vessel during operation and sampling.

  13. Good Cell Culture Practice for stem cells and stem-cell-derived models.

    Science.gov (United States)

    Pamies, David; Bal-Price, Anna; Simeonov, Anton; Tagle, Danilo; Allen, Dave; Gerhold, David; Yin, Dezhong; Pistollato, Francesca; Inutsuka, Takashi; Sullivan, Kristie; Stacey, Glyn; Salem, Harry; Leist, Marcel; Daneshian, Mardas; Vemuri, Mohan C; McFarland, Richard; Coecke, Sandra; Fitzpatrick, Suzanne C; Lakshmipathy, Uma; Mack, Amanda; Wang, Wen Bo; Yamazaki, Daiju; Sekino, Yuko; Kanda, Yasunari; Smirnova, Lena; Hartung, Thomas

    2017-01-01

    The first guidance on Good Cell Culture Practice (GCCP) dates back to 2005. This document expands this to include aspects of quality assurance for in vitro cell culture focusing on the increasingly diverse cell types and culture formats used in research, product development, testing and manufacture of biotechnology products and cell-based medicines. It provides a set of basic principles of best practice that can be used in training new personnel, reviewing and improving local procedures, and helping to assure standard practices and conditions for the comparison of data between laboratories and experimentation performed at different times. This includes recommendations for the documentation and reporting of culture conditions. It is intended as guidance to facilitate the generation of reliable data from cell culture systems, and is not intended to conflict with local or higher level legislation or regulatory requirements. It may not be possible to meet all recommendations in this guidance for practical, legal or other reasons. However, when it is necessary to divert from the principles of GCCP, the risk of decreasing the quality of work and the safety of laboratory staff should be addressed and any conclusions or alternative approaches justified. This workshop report is considered a first step toward a revised GCCP 2.0.

  14. Characterization of a novel rat cholangiocarcinoma cell culture model-CGCCA

    Institute of Scientific and Technical Information of China (English)

    Chun-Nan Yeh; Kun-Ju Lin; Tsung-Wen Chen; Ren-Ching Wu; Lee-Cheng Tsao; Ying-Tzu Chen; Wen-Hui Weng; Miin-Fu Chen

    2011-01-01

    AIM: To characterize a culture model of rat CCA cells, which were derived from a transplantable TTA-induced CCA and designated as Chang Gung CCA (CGCCA). METHODS: The CGCCA cells were cultured at in vitro passage 12 times on a culture dish in DMEM medium. To measure the doubling time, 103 cells were plated in a 96-well plate containing the growth medium. The cells were harvested 4 to 10 d after seeding, and a standard MTT assay was used to measure the growth. The phenotype of CACCA cell and xenograft was determined by immunohistochemical study. We also determine the chromosomal alterations of CGCCA, G-banding and spectral karyotyping studies were performed. The CGCCA cell line was transplanted into the nude mice for examining its tumorigenicity. 2-Deoxy-2-(18F)fluoro-Dglucose (FDG) autoradiography was also performed to evaluate the FDG uptake of the tumor xenograft. RESULTS: The doubling time for the CGCCA cell line was 32 h. After transplantation into nude mice, FDG autoradiography showed that the tumors formed at the cell transplantation site had a latency period of 4-6 wk with high FDG uptake excluding necrosis tissue. Moreover, immunohistochemical staining revealed prominent cytoplasmic expression of c-erb-B2, CK19, c-Met, COX-Ⅱ, EGFR, MUC4, and a negative expression of K-ras. All data confirmed the phenotypic features of the CGCCA cell line coincide with the xenograft mice tumors, indicating cells containing the tumorigenicity of CCA originated from CCA. In addition, karyotypic banding analysis showed that the diploid (2n) cell status combines with ring and giant rod marker chromosomes in these clones; either both types simultaneously appeared or only one type of marker chromosome in a pair appeared in a cell. The major materials contained in the marker chromosome were primarily identified from chromosome 4. CONCLUSION: The current CGCCA cell line may be used as a non-K-ras effect CCA model and to obtain information and reveal novel pathways for CCA. Further

  15. Characterization of a novel rat cholangiocarcinoma cell culture model-CGCCA.

    Science.gov (United States)

    Yeh, Chun-Nan; Lin, Kun-Ju; Chen, Tsung-Wen; Wu, Ren-Ching; Tsao, Lee-Cheng; Chen, Ying-Tzu; Weng, Wen-Hui; Chen, Miin-Fu

    2011-06-28

    To characterize a culture model of rat CCA cells, which were derived from a transplantable TTA-induced CCA and designated as Chang Gung CCA (CGCCA). The CGCCA cells were cultured at in vitro passage 12 times on a culture dish in DMEM medium. To measure the doubling time, 10(3) cells were plated in a 96-well plate containing the growth medium. The cells were harvested 4 to 10 d after seeding, and a standard MTT assay was used to measure the growth. The phenotype of CACCA cell and xenograft was determined by immunohistochemical study. We also determine the chromosomal alterations of CGCCA, G-banding and spectral karyotyping studies were performed. The CGCCA cell line was transplanted into the nude mice for examining its tumorigenicity. 2-Deoxy-2-((18)F)fluoro-D-glucose (FDG) autoradiography was also performed to evaluate the FDG uptake of the tumor xenograft. The doubling time for the CGCCA cell line was 32 h. After transplantation into nude mice, FDG autoradiography showed that the tumors formed at the cell transplantation site had a latency period of 4-6 wk with high FDG uptake excluding necrosis tissue. Moreover, immunohistochemical staining revealed prominent cytoplasmic expression of c-erb-B2, CK19, c-Met, COX-II, EGFR, MUC4, and a negative expression of K-ras. All data confirmed the phenotypic features of the CGCCA cell line coincide with the xenograft mice tumors, indicating cells containing the tumorigenicity of CCA originated from CCA. In addition, karyotypic banding analysis showed that the diploid (2n) cell status combines with ring and giant rod marker chromosomes in these clones; either both types simultaneously appeared or only one type of marker chromosome in a pair appeared in a cell. The major materials contained in the marker chromosome were primarily identified from chromosome 4. The current CGCCA cell line may be used as a non-K-ras effect CCA model and to obtain information and reveal novel pathways for CCA. Further applications regarding tumor

  16. Theoretical design of multi-colored semi-transparent organic solar cells with both efficient color filtering and light harvesting.

    Science.gov (United States)

    Wen, Long; Chen, Qin; Sun, Fuhe; Song, Shichao; Jin, Lin; Yu, Yan

    2014-11-13

    Solar cells incorporated with multi-coloring capability not only offer an aesthetic solution to bridge the gap between solar modules and building decorations but also open up the possibility for self-powered colorful display. In this paper, we proposed a multi-colored semi-transparent organic solar cells (TOSCs) design containing metallic nanostructures with the both high color purity and efficiency based on theoretical considerations. By employing guided mode resonance effect, the multi-colored TOSC behave like an efficient color filter that selectively transmits light with the desired wavelengths and generates electricity with light of other wavelengths. Broad range of coloring and luminosity adjusting for the transmission light can be achieved by simply tuning the period and the duty cycle of the metallic nanostructures. Furthermore, accompanying with the efficient color filtering characteristics, the optical absorption of TOSCs was improved due to the marked suppression of transmission loss at the off-resonance wavelengths and the increased light trapping in TOSCs. The mechanisms of the light guiding in photoactive layer and broadband backward scattering from the metallic nanostructures were identified to make an essential contribution to the improved light-harvesting. By enabling efficient color control and high efficiency simultaneously, this approach holds great promise for future versatile photovoltaic energy utilization.

  17. Layered co-sensitization of gardenia and monascus for panchromatic light harvesting in dye-sensitized solar cells

    Science.gov (United States)

    Kwon, Oh Oun; Lee, Hyo Jung; Kim, Sang-Wook; Kim, Jung-Hun; Kim, Tae-Young; Park, Kyung-Hee; Lee, Jae-Wook

    2015-04-01

    TiO2 electrodes adsorbed with two natural dyes (gardenia yellow and monascus) were used as sensitizers to improve the conversion efficiency of cocktail dye-sensitized solar cells (CDSC) for light harvesting over a wide range of wavelength. Adsorption and electrochemical properties of two dyes were evaluated based on adsorption kinetics and electrochemical measurements. In addition, the photovoltaic performance of a photo-electrode adsorbed with single-dye (gardenia yellow and monascus) or the mixture or successive adsorption of the two dyes, was evaluated from current-voltage measurements. Layered co-sensitization of the two natural dyes was compared depending on the adsorption modes. As for the TiO2 electrode with successive adsorption of monascus and gardenia yellow dyes, the solar cell yields a short-circuit current density (Jsc) of 2.04 mA/cm2, a photovoltage (Voc) of 0.63 V, and a fill factor of 0.64, corresponding to an energy conversion efficiency (η) of 0.82%.

  18. EXPLANTATION OF MESANGIAL CELL HILLOCKS - A METHOD FOR OBTAINING HUMAN MESANGIAL CELLS IN CULTURE

    NARCIS (Netherlands)

    MULLER, EW; KIM, Y; MICHAEL, AF; VERNIER, RL; VANDERHEM, GK; VANDERWOUDE, FJ

    1992-01-01

    A simple method is presented for selective cell culture of human mesangial cells using explanatation of mesangial cell hillocks. Glomeruli which had been incubated with collagenase were explanted on plastic tissue culture flasks. Three to 6 weeks after explantation, a rapidly growing multilayer of e

  19. EXPLANTATION OF MESANGIAL CELL HILLOCKS - A METHOD FOR OBTAINING HUMAN MESANGIAL CELLS IN CULTURE

    NARCIS (Netherlands)

    MULLER, EW; KIM, Y; MICHAEL, AF; VERNIER, RL; VANDERHEM, GK; VANDERWOUDE, FJ

    1992-01-01

    A simple method is presented for selective cell culture of human mesangial cells using explanatation of mesangial cell hillocks. Glomeruli which had been incubated with collagenase were explanted on plastic tissue culture flasks. Three to 6 weeks after explantation, a rapidly growing multilayer of e

  20. Learning about Cells as Dynamic Entities: An Inquiry-Driven Cell Culture Project

    Science.gov (United States)

    Palombi, Peggy Shadduck; Jagger, Kathleen Snell

    2008-01-01

    Using cultured fibroblast cells, undergraduate students explore cell division and the responses of cultured cells to a variety of environmental changes. The students learn new research techniques and carry out a self-designed experiment. Through this project, students enhance their creative approach to scientific inquiry, learn time-management and…

  1. Cell culture process development: advances in process engineering.

    Science.gov (United States)

    Heath, Carole; Kiss, Robert

    2007-01-01

    Representatives from the cell culture process development community met on September 11 and 12, 2006 at the ACS National Meeting in San Francisco to discuss "Cell Culture Process Development: Advances in Process Engineering". This oral session was held as part of the Division of Biochemical Technology (BIOT) program. The presentations addressed the very small scale (less than 1 mL) to the very large scale (20,000 L). The topics covered included development of high throughput cell culture screening systems, modeling and characterization of bioreactor environments from mixing and shear perspectives at both small and large scales, systematic approaches for improving scale-up and scale-down activities, development of disposable bioreactor technologies, and novel perfusion culture approaches. All told, this well-attended session resulted in a valuable exchange of technical information and demonstrated a high level of interest within the process development community.

  2. Stability of resazurin in buffers and mammalian cell culture media

    DEFF Research Database (Denmark)

    Rasmussen, Eva; Nicolaisen, G.M.

    1999-01-01

    The utility of a ferricyanide/ferrocyanide system used in the AlamarBlue(TM) (Serotec, Oxford, UK) vital. dye to inhibit the reduction of resazurin by mammalian cell culture media is questioned. Resazurin was found to be relatively stable when dissolved in phosphate-buffered saline (PBS). The use...... of HEPES resulted in a huge immediate dye reduction, which was significantly enhanced by exposure to diffuse light from fluorescent tubes in the laboratory 8 h per day. The reduction of resazurin by various cell culture media was time and temperature dependent, and it was significantly enhanced......'s nutrient mixture F-10 and F-12. Fetal calf serum (5-20%) slightly decreased resazurin reduction during the first 2 days of incubation. The reduction of resazurin by mammalian cell culture media do not appear to be problematic under normal culture conditions, and it is primarily dependent upon the presence...

  3. Current progress and future prospect of microalgal biomass harvest using various flocculation technologies.

    Science.gov (United States)

    Wan, Chun; Alam, Md Asraful; Zhao, Xin-Qing; Zhang, Xiao-Yue; Guo, Suo-Lian; Ho, Shih-Hsin; Chang, Jo-Shu; Bai, Feng-Wu

    2015-05-01

    Microalgae have been extensively studied for the production of various valuable products. Application of microalgae for the production of renewable energy has also received increasing attention in recent years. However, high cost of microalgal biomass harvesting is one of the bottlenecks for commercialization of microalgae-based industrial processes. Considering harvesting efficiency, operation economics and technological feasibility, flocculation is a superior method to harvest microalgae from mass culture. In this article, the latest progress of various microalgal cell harvesting methods via flocculation is reviewed with the emphasis on the current progress and prospect in environmentally friendly bio-based flocculation. Harvesting microalgae through bio-based flocculation is a promising component of the low-cost microalgal biomass production technology.

  4. Modeling of cell culture damage and recovery leads to increased antibody and biomass productivity in CHO cell cultures.

    Science.gov (United States)

    Naderi, Saeideh; Nikdel, Ali; Meshram, Mukesh; McConkey, Brendan; Ingalls, Brian; Budman, Hector; Scharer, Jeno

    2014-09-01

    The development of an efficient and productive cell-culture process requires a deep understanding of intracellular mechanisms and extracellular conditions for optimal product synthesis. Mathematical modeling provides an effective strategy to predict, control, and optimize cell performance under a range of culture conditions. In this study, a mathematical model is proposed for the investigation of cell damage of a Chinese hamster ovary cell culture secreting recombinant anti-RhD monoclonal antibody (mAb). Irreversible cell damage was found to be correlated with a reduction in pH. This irreversible damage to cellular function is described mathematically by a Tessier-based model, in which the actively growing fraction of cells is dependent on an intracellular metabolic product acting as a growth inhibitor. To further verify the model, an offline model-based optimization of mAb production in the cell culture was carried out, with the goal of minimizing cell damage and thereby enhancing productivity through intermittent refreshment of the culture medium. An experimental implementation of this model-based strategy resulted in a doubling of the yield as compared to the batch operation and the resulting biomass and productivity profiles agreed with the model predictions.

  5. Introducing Mammalian Cell Culture and Cell Viability Techniques in the Undergraduate Biology Laboratory.

    Science.gov (United States)

    Bowey-Dellinger, Kristen; Dixon, Luke; Ackerman, Kristin; Vigueira, Cynthia; Suh, Yewseok K; Lyda, Todd; Sapp, Kelli; Grider, Michael; Crater, Dinene; Russell, Travis; Elias, Michael; Coffield, V McNeil; Segarra, Verónica A

    2017-01-01

    Undergraduate students learn about mammalian cell culture applications in introductory biology courses. However, laboratory modules are rarely designed to provide hands-on experience with mammalian cells or teach cell culture techniques, such as trypsinization and cell counting. Students are more likely to learn about cell culture using bacteria or yeast, as they are typically easier to grow, culture, and manipulate given the equipment, tools, and environment of most undergraduate biology laboratories. In contrast, the utilization of mammalian cells requires a dedicated biological safety cabinet and rigorous antiseptic techniques. For this reason, we have devised a laboratory module and method herein that familiarizes students with common cell culture procedures, without the use of a sterile hood or large cell culture facility. Students design and perform a time-efficient inquiry-based cell viability experiment using HeLa cells and tools that are readily available in an undergraduate biology laboratory. Students will become familiar with common techniques such as trypsinizing cells, cell counting with a hemocytometer, performing serial dilutions, and determining cell viability using trypan blue dye. Additionally, students will work with graphing software to analyze their data and think critically about the mechanism of death on a cellular level. Two different adaptations of this inquiry-based lab are presented-one for non-biology majors and one for biology majors. Overall, these laboratories aim to expose students to mammalian cell culture and basic techniques and help them to conceptualize their application in scientific research.

  6. Canine muscle cell culture and consecutive patch-clamp measurements - a new approach to characterize muscular diseases in dogs

    Directory of Open Access Journals (Sweden)

    Schenk Henning Christian

    2012-11-01

    Full Text Available Abstract Background The recognition of functional muscular disorders, (e.g. channelopathies like Myotonia is rising in veterinary neurology. Morphologic (e.g. histology and even genetic based studies in these diseases are not able to elucidate the functional pathomechanism. As there is a deficit of knowledge and skills considering this special task, the aim of the current pilot study was to develop a canine muscle cell culture system derived from muscle biopsies of healthy client-owned dogs, which allows sampling of the biopsies under working conditions in the daily veterinary practise. Results Muscular biopsies from 16 dogs of different age and breed were taken during standard surgical procedures and were stored for one to three days at 4°C in a transport medium in order to simulate shipping conditions. Afterwards biopsies were professionally processed, including harvesting of satellite cells, inducing their proliferation, differentiating them into myotubes and recultivating myotubes after long-term storage in liquid nitrogen. Myogenic origin of cultured cells was determined by immunofluorescence, immunohistology and by their typical morphology after inducing differentiation. Subsequent to the differentiation into myotubes feasibility of patch-clamp recordings of voltage gated ion channels was successfully. Conclusion We have developed a canine muscle cell culture system, which allows sampling of biopsies from young and old dogs of different breeds under practical conditions. Patch clamp measurements can be carried out with the cultured myotubes demonstrating potential of these cells as source for functional research.

  7. Interactions between airway epithelial cells and dendritic cells during viral infections using an in vitro co-culture model

    Science.gov (United States)

    Rationale: Historically, single cell culture models have been limited in pathological and physiological relevance. A co-culture model of dendritic cells (DCs) and differentiated human airway epithelial cells was developed to examine potential interactions between these two cell t...

  8. Callus and cell suspension cultures of carnation

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen

    1972-01-01

    Callus cultures of carnation, Dianthus caryophyllus L. ev. G. J. Sim, were grown on a synthetic medium of half strength Murashige and Skoog salts, 3 % sucrose, 100 mg/l of myo-inositol, 0.5 mg/l each of thiamin, HCl, pyridoxin, HCl and nicotinic acid and 10 g/l agar. Optimal concentrations of gro......, but all attempts to induce formation of shoots or em-bryoids gave negative results....

  9. Enhanced light harvesting of dye-sensitized solar cells with TiO2 microspheres as light scattering layer

    Science.gov (United States)

    Guan, Yingli; Song, Lixin; Zhou, Yangyang; Yin, Xin; Xie, Xueyao; Xiong, Jie

    2017-03-01

    Two kinds of TiO2 microspheres (TMS) with average diameter of 1500 nm but different surface were fabricated by solvothermal method from different Ti source. The effect of TMS on the light harvesting and photovoltaic performance of dye-sensitized solar cells (DSSCs)was investigated. The UV-Vis diffusion reflectance spectra and absorption spectra of N719 dye in detached solutions proved that the TMS showed dual functions of light scattering and dye-adsorption which was an important functional material in DSSCs. The results showed that the TMS made from titanium(IV) isopropoxide with rough surface (TMSR) exhibited better photovoltaic performance than that of TMS made from tetrabutyl titanate with smooth surface (TMSS). To further improve the photovoltaic performance, the double-layered DSSCs made of P25 as an underlayer and TMS as a light-scattering layer (P25-TMS) were fabricated. The photovoltaic performance of double-layered DSSCs was higher than that of the single-layered DSSCs with similar thickness. Especially, the DSSCs made of P25 as an underlayer and the TMSR as a light-scattering layer (P25-TMSR) had a highest power conversion efficiency of 7.62%. This was higher than that of single-layered TMSR-based cell (5.54%), P25-based cell (5.75%), and double-layered P25-TMSS-based cell (6.78%) with similar thickness. This was mainly attributed to the large specific surface area, superior light scattering ability, and fast electron transport of TMSR.

  10. In vitro methods to culture primary human breast epithelial cells.

    Science.gov (United States)

    Raouf, Afshin; Sun, Yu Jia

    2013-01-01

    Current evidence suggests that much like leukemia, breast tumors are maintained by a small subpopulation of tumor cells that have stem cell properties. These cancer stem cells are envisaged to be responsible for tumor formation and relapse. Therefore, knowledge about their nature will provide a platform to develop therapies to eliminate these breast cancer stem cells. This concept highlights the need to understand the mechanisms that regulate the normal functions of the breast stem cells and their immediate progeny as alterations to these same mechanisms can cause these primitive cells to act as cancer stem cells. The study of the primitive cell functions relies on the ability to isolate them from primary sources of breast tissue. This chapter describes processing of discarded tissue from reduction mammoplasty samples as sources of normal primary human breast epithelial cells and describes cell culture systems to grow single-cell suspensions prepared from these reduction samples in vitro.

  11. Metabolism Kinetics of Glucose in Anchorage-dependent Cell Cultures

    Institute of Scientific and Technical Information of China (English)

    孙祥明; 张元兴

    2001-01-01

    The kinetic model of glucose metabolism was established and successfully applied to batchcultures of rCHO and rBHK cells. It was found that a large amount of glucose was utilized for cellmaintenance, and the overwhelming majority of maintenance energy from glucose was by its anaerobicmetabolism in both rBHK and rCHO cell cultures. The overall maintenance coefficients from aerobicmetabolism were 1.9×10-13 mmol/(cell.h) for rCHO cells and 7×10-13 mmol/(cell.h) for rBHK cells. Inaddition, all Go/T and Eo/T gradually increased with the same trend as the cell growth in the culture ofboth rCHO and rBHK cells. The overall molecule yield coefficients of lactate to glucose were 1.61 for rCHO cells and 1.38 for rBHK cells. The yield coefficients of cell to glucose were 4.5×108 cells/mmol for rCHO cells and 1.9 × 108 cells/mmol for rBHK cells, respectively.

  12. Periodically arranged colloidal gold nanoparticles for enhanced light harvesting in organic solar cells

    DEFF Research Database (Denmark)

    Mirsafaei, Mina; Fernandes Cauduro, André Luis; Kunstmann-Olsen, Casper

    2016-01-01

    , which makes it possible to improve the light absorption and charge extraction in the device’s active layer. Here, periodically arranged colloidal gold nanoparticles are demonstrated experimentally and theoretically to improve light absorption and thus enhance the efficiency of organic solar cells....... Surface-ordered gold nanoparticle arrangements are integrated at the bottom electrode of organic solar cells. The resulting optical interference and absorption effects are numerically investigated in bulk hetero-junction solar cells based on the Finite-Difference Time-Domain (FDTD) and Transfer Matrix...... Method (TMM) and as a function of size and periodicity of the plasmonic arrangements. In addition, light absorption enhancement in the organic active layer is investigated experimentally following integration of the nanoparticle arrangements. The latter are fabricated using a lithography-free stamping...

  13. Power Harvesting from Human Serum in Buckypaper-Based Enzymatic Biofuel Cell

    Directory of Open Access Journals (Sweden)

    Güray eGüven

    2016-02-01

    Full Text Available The requirement for a miniature, high density, long life, rechargeable power source is common to a vast majority of microsystems, including the implantable devices for medical applications. A model biofuel cell system operating in human serum has been studied for future applications of biomedical and implantable medical devices. Anodic and cathodic electrodes were made of carbon nanotube –buckypaper modified with PQQ-dependent glucose dehydrogenase and laccase, respectively. Modified electrodes were characterized electrochemically and assembled in a biofuel cell set-up. Power density of 16.12 μW/cm2 was achieved in human serum for lower than physiological glucose concentrations. Increasing the glucose concentration and biofuel cell temperature caused an increase on power output leading up to 49.16 μW/cm2.

  14. Increased light harvesting in dye-sensitized solar cells with energy relay dyes

    KAUST Repository

    Hardin, Brian E.

    2009-06-21

    Conventional dye-sensitized solar cells have excellent charge collection efficiencies, high open-circuit voltages and good fill factors. However, dye-sensitized solar cells do not completely absorb all of the photons from the visible and near-infrared domain and consequently have lower short-circuit photocurrent densities than inorganic photovoltaic devices. Here, we present a new design where high-energy photons are absorbed by highly photoluminescent chromophores unattached to the titania and undergo Förster resonant energy transfer to the sensitizing dye. This novel architecture allows for broader spectral absorption, an increase in dye loading, and relaxes the design requirements for the sensitizing dye. We demonstrate a 26% increase in power conversion efficiency when using an energy relay dye (PTCDI) with an organic sensitizing dye (TT1). We estimate the average excitation transfer efficiency in this system to be at least 47%. This system offers a viable pathway to develop more efficient dye-sensitized solar cells.

  15. Challenges of culturing human norovirus in three-dimensional organoid intestinal cell culture models.

    Directory of Open Access Journals (Sweden)

    Efstathia Papafragkou

    Full Text Available Human noroviruses are the most common cause of acute gastroenteritis worldwide. Recently, cell culture systems have been described using either human embryonic intestinal epithelial cells (Int-407 or human epithelial colorectal adenocarcinoma cells (Caco-2 growing on collagen-I porous micro carrier beads in a rotating bioreactor under conditions of physiological fluid shear. Here, we describe the efforts from two independent laboratories to implement this three dimensional (3D cell culture system for the replication of norovirus. Int-407 and Caco-2 were grown in a rotating bioreactor for up to 28 days. Prior to infection, cells were screened for the presence of microvilli by electron microscopy and stained for junction proteins (zonula occludens-1, claudin-1, and β-catenin. Differentiated 3D cells were transferred to 24-well plates and infected with bacteria-free filtrates of various norovirus genotypes (GI.1, GI.3, GI.8, GII.2, GII.4, GII.7, and GII.8. At 12 h, 24 h, and 48 h post inoculation, viral RNA from both cells and supernatants were collected and analyzed for norovirus RNA by real-time reverse transcription PCR. Despite observations of high expression of junction proteins and microvilli development in stained thin sections, our data suggest no significant increase in viral titer based on norovirus RNA copy number during the first 48 h after inoculation for the different samples and virus culture conditions tested. Our combined efforts demonstrate that 3D cell culture models using Int-407 or Caco-2 cells do not support norovirus replication and highlight the complexity and difficulty of developing a reproducible in vitro cell culture system for human norovirus.

  16. Miniaturized concentration cells for small-scale energy harvesting based on reverse electrodialysis

    Science.gov (United States)

    Banan Sadeghian, Ramin; Pantchenko, Oxana; Tate, Daniel; Shakouri, Ali

    2011-10-01

    We describe experimental and theoretical results that demonstrate the feasibility of power generation using concentration cells based on ionic concentration gradients and reverse electrodialysis. A peak power density of 0.2 (0.7) μW cm-2 and a maximum energy density of 0.4 (0.4) mJ cm-3 delivered in 3 h to a 2 (5) kΩ resistor were recorded using a microfiltration (anion exchange) membrane, respectively. A comprehensive model is developed to predict the evolution of the output voltage with time in relation to the solute concentration in each cell and derive the power density and efficiency limits.

  17. Bioinspired Organic PV Cells Using Photosynthetic Pigment Complex for Energy Harvesting Materials

    Science.gov (United States)

    2010-05-10

    electron transfer from TiO2  and stabilizes the resultant charge-separated state between TiOand carotenoid. No dye-based PV solar cells have...as TiO2 as shown bellow, collaborated with Prof. Minoru Taya, University of Washinton in Seattle,US. 10 Scheme 4. Schemetic model of dye...sensitized solar cell ( DSSC ) Design of Dye using tandem system Electronic integration of devices were achieved by self-assembled monolayers with

  18. Seed train optimization for cell culture.

    Science.gov (United States)

    Frahm, Björn

    2014-01-01

    For the production of biopharmaceuticals a seed train is required to generate an adequate number of cells for inoculation of the production bioreactor. This seed train is time- and cost-intensive but offers potential for optimization. A method and a protocol are described for the seed train mapping, directed modeling without major effort, and its optimization regarding selected optimization criteria such as optimal points in time for cell passaging. Furthermore, the method can also be applied for the set-up of a new seed train, for example for a new cell line. Although the chapter is directed towards suspension cell lines, the method is also generally applicable, e.g. for adherent cell lines.

  19. Characterisation and germline transmission of cultured avian primordial germ cells.

    Directory of Open Access Journals (Sweden)

    Joni Macdonald

    Full Text Available BACKGROUND: Avian primordial germ cells (PGCs have significant potential to be used as a cell-based system for the study and preservation of avian germplasm, and the genetic modification of the avian genome. It was previously reported that PGCs from chicken embryos can be propagated in culture and contribute to the germ cell lineage of host birds. PRINCIPAL FINDINGS: We confirm these results by demonstrating that PGCs from a different layer breed of chickens can be propagated for extended periods in vitro. We demonstrate that intracellular signalling through PI3K and MEK is necessary for PGC growth. We carried out an initial characterisation of these cells. We find that cultured PGCs contain large lipid vacuoles, are glycogen rich, and express the stem cell marker, SSEA-1. These cells also express the germ cell-specific proteins CVH and CDH. Unexpectedly, using RT-PCR we show that cultured PGCs express the pluripotency genes c-Myc, cKlf4, cPouV, cSox2, and cNanog. Finally, we demonstrate that the cultured PGCs will migrate to and colonise the forming gonad of host embryos. Male PGCs will colonise the female gonad and enter meiosis, but are lost from the gonad during sexual development. In male hosts, cultured PGCs form functional gametes as demonstrated by the generation of viable offspring. CONCLUSIONS: The establishment of in vitro cultures of germline competent avian PGCs offers a unique system for the study of early germ cell differentiation and also a comparative system for mammalian germ cell development. Primary PGC lines will form the basis of an alternative technique for the preservation of avian germplasm and will be a valuable tool for transgenic technology, with both research and industrial applications.

  20. Derivation of completely cell culture-derived mice from early-passage embryonic stem cells.

    OpenAIRE

    Nagy, A.; Rossant, J.; Nagy, R.; Abramow-Newerly, W; Roder, J C

    1993-01-01

    Several newly generated mouse embryonic stem (ES) cell lines were tested for their ability to produce completely ES cell-derived mice at early passage numbers by ES cell tetraploid embryo aggregation. One line, designated R1, produced live offspring which were completely ES cell-derived as judged by isoenzyme analysis and coat color. These cell culture-derived animals were normal, viable, and fertile. However, prolonged in vitro culture negatively affected this initial totipotency of R1, and...

  1. Suspension culture of pluripotent stem cells: effect of shear on stem cell fate.

    Science.gov (United States)

    Keller, Kevin C; Rodrigues, Beatriz; zur Nieden, Nicole I

    2014-01-01

    Despite significant promise, the routine usage of suspension cell culture to manufacture stem cell-derived differentiated cells has progressed slowly. Suspension culture is an innovative way of either expanding or differentiating cells and sometimes both are combined into a single bioprocess. Its advantages over static 2D culturing include a homogeneous and controllable culture environment and producing a large quantity of cells in a fraction of time. This feature makes suspension cell culture ideal for use in stem cell research and eventually ideal in the large-scale production of differentiated cells for regenerative medicine. Because of their tremendous differentiation capacities and unlimited growth properties, pluripotent stem cells (PSCs) in particular are considered potential sources for future cell-replacement therapies. Currently, expansion of PSCs is accomplished in 2D, which only permits a limited amount of cell growth per culture flask before cells need to be passaged. However, before stem cells can be applied clinically, several aspects of their expansion, such as directed growth, but also differentiation, need to be better controlled. This review will summarize recent advantages in suspension culture of PSCs, while at the same time highlighting current challenges.

  2. Imprinting of confining sites for cell cultures on thermoplastic substrates

    Science.gov (United States)

    Cone, C. D.; Fleenor, E. N.

    1969-01-01

    Prevention of test cell migration beyond the field of observation involves confining cells or cultures in microlagoons made in either a layer of grease or a thermoplastic substrate. Thermoplastic films or dishes are easily imprinted with specifically designed patterns of microlagoons.

  3. Effect of Nanoparticles on Complement System in Cell Culture Model

    Science.gov (United States)

    2006-09-15

    7 Primary endothelial cells isolated from human umbilical veins Aseptically taken umbilical cord, preferably abort 20...suspended in cell culture medium. Prepared suspensions were agitated with ultrasounds for 20 minutes at 37C, then stored at +4C and used for testing on the

  4. Animal-cell culture in aqueous two-phase systems.

    NARCIS (Netherlands)

    Zijlstra, G.M.

    1998-01-01

    In current industrial biotechnology, animal-cell culture is an important source of therapeutic protein products. The conventional animal-cell production processes, however, include many unit operations as part of the fermentation and downstream processing strategy. The research described in this the

  5. Process validation for cell culture-derived pharmaceutical proteins.

    Science.gov (United States)

    Lubiniecki, A S; Wiebe, M E; Builder, S E

    1990-01-01

    Principles of process validation are extremely powerful tools in assurance of product quality. They are especially useful for reducing those risks not easily measured routinely during production. When combined with effective process and facility design principles, characterization of cell banks and products, appropriate lot release tests, and adherence to cGMP, safe cell culture biologicals can be prepared in a reliable manner.

  6. Isolation and Characterization of Poliovirus in Cell Culture Systems.

    Science.gov (United States)

    Thorley, Bruce R; Roberts, Jason A

    2016-01-01

    The isolation and characterization of enteroviruses by cell culture was accepted as the "gold standard" by clinical virology laboratories. Methods for the direct detection of all enteroviruses by reverse transcription polymerase chain reaction, targeting a conserved region of the genome, have largely supplanted cell culture as the principal diagnostic procedure. However, the World Health Organization's Global Polio Eradication Initiative continues to rely upon cell culture to isolate poliovirus due to the lack of a reliable sensitive genetic test for direct typing of enteroviruses from clinical specimens. Poliovirus is able to infect a wide range of mammalian cell lines, with CD155 identified as the primary human receptor for all three seroytpes, and virus replication leads to an observable cytopathic effect. Inoculation of cell lines with extracts of clinical specimens and subsequent passaging of the cells leads to an increased virus titre. Cultured isolates of poliovirus are suitable for testing by a variety of methods and remain viable for years when stored at low temperature.This chapter describes general procedures for establishing a cell bank and routine passaging of cell lines. While the sections on specimen preparation and virus isolation focus on poliovirus, the protocols are suitable for other enteroviruses.

  7. Quantitative phase imaging for cell culture quality control.

    Science.gov (United States)

    Kastl, Lena; Isbach, Michael; Dirksen, Dieter; Schnekenburger, Jürgen; Kemper, Björn

    2017-05-01

    The potential of quantitative phase imaging (QPI) with digital holographic microscopy (DHM) for quantification of cell culture quality was explored. Label-free QPI of detached single cells in suspension was performed by Michelson interferometer-based self-interference DHM. Two pancreatic tumor cell lines were chosen as cellular model and analyzed for refractive index, volume, and dry mass under varying culture conditions. Firstly, adequate cell numbers for reliable statistics were identified. Then, to characterize the performance and reproducibility of the method, we compared results from independently repeated measurements and quantified the cellular response to osmolality changes of the cell culture medium. Finally, it was demonstrated that the evaluation of QPI images allows the extraction of absolute cell parameters which are related to cell layer confluence states. In summary, the results show that QPI enables label-free imaging cytometry, which provides novel complementary integral biophysical data sets for sophisticated quantification of cell culture quality with minimized sample preparation. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

  8. Cell cultures from the symbiotic soft coral Sinularia flexibilis

    NARCIS (Netherlands)

    Khalesi, M.K.; Vera-Jimenez, N.I.; Aanen, D.K.; Beeftink, H.H.; Wijffels, R.H.

    2008-01-01

    The symbiotic octocoral Sinularia flexibilis is a producer of potential pharmaceuticals. Sustainable mass production of these corals as a source of such compounds demands innovative approaches, including coral cell culture. We studied various cell dissociation methodologies and the feasibility of cu

  9. Animal-cell culture in aqueous two-phase systems

    NARCIS (Netherlands)

    Zijlstra, G.M.

    1998-01-01

    In current industrial biotechnology, animal-cell culture is an important source of therapeutic protein products. The conventional animal-cell production processes, however, include many unit operations as part of the fermentation and downstream processing strategy. The research described in

  10. Replica-moulded polydimethylsiloxane culture vessel lids attenuate osmotic drift in long-term cell cultures

    Indian Academy of Sciences (India)

    Axel Blau; Tanja Neumann; Christiane Ziegler; Fabio Benfenati

    2009-03-01

    An imbalance in medium osmolarity is a determinant that affects cell culture longevity. Even in humidified incubators, evaporation of water leads to a gradual increase in osmolarity overtime. We present a simple replica-moulding strategy for producing self-sealing lids adaptable to standard, small-size cell-culture vessels. They are made of polydimethylsiloxane (PDMS), a flexible, transparent and biocompatible material, which is gas-permeable but largely impermeable to water. Keeping cell cultures in a humidified 5% CO2 incubator at 37°C, medium osmolarity increased by +6.86 mosmol/kg/day in standard 35 mm Petri dishes, while PDMS lids attenuated its rise by a factor of four to changes of +1.72 mosmol/kg/ day. Depending on the lid membrane thickness, pH drifts at ambient CO2 levels were attenuated by a factor of 4 to 9. Comparative evaporation studies at temperatures below 60°C yielded a 10-fold reduced water vapour flux of 1.75 g/day/dm2 through PDMS lids as compared with 18.69 g/day/dm2 with conventional Petri dishes. Using such PDMS lids, about 2/3 of the cell cultures grew longer than 30 days in vitro. Among these, the average survival time was 69 days with the longest survival being 284 days under otherwise conventional cell culture conditions.

  11. Cultivation and energy efficient harvesting of microalgae using thermoreversible sol-gel transition

    Science.gov (United States)

    Estime, Bendy; Ren, Dacheng; Sureshkumar, Radhakrishna

    2017-01-01

    Microalgae represent a promising source of renewable biomass for the production of biofuels and valuable chemicals. However, energy efficient cultivation and harvesting technologies are necessary to improve economic viability. A Tris-Acetate-Phosphate-Pluronic (TAPP) medium that undergoes a thermoreversible sol-gel transition is developed to efficiently culture and harvest microalgae without affecting the productivity as compared to that in traditional culture in a well-mixed suspension. After seeding microalgae in the TAPP medium in a solution phase at 15 °C, the temperature is increased by 7 °C to induce gelation. Within the gel, microalgae are observed to grow in large clusters rather than as isolated cells. The settling velocity of the microalgal clusters is approximately ten times larger than that of individual cells cultured in typical solution media. Such clusters are easily harvested gravimetrically by decreasing the temperature to bring the medium to a solution phase.

  12. Cultivation and energy efficient harvesting of microalgae using thermoreversible sol-gel transition

    Science.gov (United States)

    Estime, Bendy; Ren, Dacheng; Sureshkumar, Radhakrishna

    2017-01-01

    Microalgae represent a promising source of renewable biomass for the production of biofuels and valuable chemicals. However, energy efficient cultivation and harvesting technologies are necessary to improve economic viability. A Tris-Acetate-Phosphate-Pluronic (TAPP) medium that undergoes a thermoreversible sol-gel transition is developed to efficiently culture and harvest microalgae without affecting the productivity as compared to that in traditional culture in a well-mixed suspension. After seeding microalgae in the TAPP medium in a solution phase at 15 °C, the temperature is increased by 7 °C to induce gelation. Within the gel, microalgae are observed to grow in large clusters rather than as isolated cells. The settling velocity of the microalgal clusters is approximately ten times larger than that of individual cells cultured in typical solution media. Such clusters are easily harvested gravimetrically by decreasing the temperature to bring the medium to a solution phase. PMID:28102313

  13. Canola Oil Fuel Cell Demonstration: Volume 3 - Technical, Commercialization, and Application Issues Associated with Harvested Biomass

    Science.gov (United States)

    2006-08-17

    Fuels for Fuel Cells.” International Journal of Hydrogen Energy , vol 26, pp. 291-301. Arthur D. Little, Inc. 2001. Conceptual Design of POX / SOFC 5...Compact Plasmatron-Boosted Hydrogen Generation Technology for Vehicular Applications.” International Journal of Hydrogen Energy , No. 24. pp. 341

  14. Combining light-harvesting with detachability in high-efficiency thin-film silicon solar cells

    DEFF Research Database (Denmark)

    Ram, Sanjay K.; Desta, Derese; Rizzoli, Rita

    2017-01-01

    the substrate by dissolution of the sacrificial NaCl layer in water and then transferred onto a plastic sheet, with a resultant post-transfer efficiency of 9%. The light-trapping effect of the surface nanotextures originating from the NaCl layer on the overlying solar cell is studied theoretically...

  15. Enhancement of Diosgenin Production in Dioscorea zingiberensis Cell Cultures by Oligosaccharides from Its Endophytic Fungus Fusarium oxysporum Dzf17

    Directory of Open Access Journals (Sweden)

    Ligang Zhou

    2011-12-01

    Full Text Available The effects of the oligosaccharides from the endophytic fungus Fusarium oxysporum Dzf17 as elicitors on diosgenin production in cell suspension cultures of its host Dioscorea zingiberensis were investigated. Three oligosaccharides, DP4, DP7 and DP10, were purified from the oligosaccharide fractions DP2-5, DP5-8 and DP8-12, respectively, which were prepared from the water-extracted mycelial polysaccharide of the endophytic fungus F. oxysporum Dzf17. When the cell cultures were treated with fraction DP5-8 at 20 mg/L on day 26 and harvested on day 32, the maximum diosgenin yield (2.187 mg/L was achieved, which was 5.65-fold of control (0.387 mg/L. When oligosaccharides DP4, DP7 and DP10 were individually added to 26-day-old D. zingiberensis cell cultures at concentrations of 2, 4, 6, 8 and 10 mg/L in medium, DP7 at 6 mg/L was found to significantly enhance diosgenin production, with a yield of 3.202 mg/L, which was 8.27-fold of control. When the cell cultures were treated with DP7 twice on days 24 and 26, and harvested on day 30, both diosgenin content and yield were significantly increased and reached the maximums of 1.159 mg/g dw and 4.843 mg/L, both of which were higher than those of single elicitation, and were 9.19- and 12.38-fold of control, respectively.

  16. Radiosensitivity of cultured insect cells: I. Lepidoptera

    Energy Technology Data Exchange (ETDEWEB)

    Koval, T.M.

    1983-10-01

    The radiosensitivity of five lepidopteran insect cell lines representing five different genera has been investigated. These lines are: (1) TN-368, Trichoplusia ni; (2) IPLB-SF-1254, Spodoptera frugiperda; (3) IPLB-1075, Heliothis zea; (4) MRRL-CHl, clone GVl, Manduca sexta; and (5) IAL-PID2, Plodia interpunctella. The cell lines grew at different rates and had population doubling times that ranged from 19 to 52 hr. All of the lines are highly heteroploid and have approximate chromosome numbers near or above 100. The chromosomes are very small. All of the lines are extremely radioresistant; cell populations are able to recover from 260 kVp X-ray exposures up to and including 400 Gy, the highest dose examined. Cell survival curves were obtainable for only the TN-368 and IPLB-SF-1254 lines. The TN-368 cells displayed a biphasic survival response with D/sub 0/, d/sub q/, and n values of 65.7 and 130.2 Gy, 9.0 and -36.1 Gy, and 1.2 and 0.8, respectively, for the steep and shallow portions of the curve. The IPLB-SF-1254 cells had a D/sub 0/ of 63.9 Gy. D/sub q/ of 19.0 Gy, and n value of 1.4. These studies provide definitive evidence of the radioresistance of lepidopteran cells, and suggest that this radioresistance is a characteristic of lepidopteran insects.

  17. Phenotypic changes in satellite glial cells in cultured trigeminal ganglia.

    Science.gov (United States)

    Belzer, Vitali; Shraer, Nathanael; Hanani, Menachem

    2010-11-01

    Satellite glial cells (SGCs) are specialized cells that form a tight sheath around neurons in sensory ganglia. In recent years, there is increasing interest in SGCs and they have been studied in both intact ganglia and in tissue culture. Here we studied phenotypic changes in SGCs in cultured trigeminal ganglia from adult mice, containing both neurons and SGCs, using phase optics, immunohistochemistry and time-lapse photography. Cultures were followed for up to 14 days. After isolation virtually every sensory neuron is ensheathed by SGCs, as in the intact ganglia. After one day in culture, SGCs begin to migrate away from their parent neurons, but in most cases the neurons still retain an intact glial cover. At later times in culture, there is a massive migration of SGCs away from the neurons and they undergo clear morphological changes, and at 7 days they become spindle-shaped. At one day in culture SGCs express the glial marker glutamine synthetase, and also the purinergic receptor P2X7. From day 2 in culture the glutamine synthetase expression is greatly diminished, whereas that of P2X7 is largely unchanged. We conclude that SGCs retain most of their characteristics for about 24 h after culturing, but undergo major phenotypic changes at later times.

  18. Schwann cell cultures from human fetal dorsal root ganglia

    Institute of Scientific and Technical Information of China (English)

    Yaping Feng; Hui Zhu; Jiang Hao; Xinmin Wang; Shengping Wu; Li Bai; Xiangming Li; Yun Zha

    2009-01-01

    BACKGROUND:Previous studies have used many methods for in vitro Schwann cells (SCs) cul-tures and purification,such as single cell suspension and cytosine arabinoside.However,it has been difficult to obtain sufficient cellular density,and the procedures have been quite tedious.OBJECTIVE:To investigate the feasibility of culturing high-density SCs using fetal human dorsal root ganglion tissue explants.DESIGN,TIME AND SETTING:Cell culture and immunohistochemistry were performed at the Cen-tral Laboratory of Kunming General Hospital of Chinese PLA between March 2001 and October 2008.MATERIALS:Culture media containing 10% fetal bovine serum,as well as 0.2% collagenase and 0.25% trypsin were purchased from Gibco,USA;mouse anti-human S-100 monoclonal antibody and goat anti-mouse IgG labeled with horseradish peroxidase were provided by Beijing Institute of Bi-ological Products,China.METHODS:Primarily cultured SCs were dissociated from dorsal root ganglia of human aborted fe-tuses at 4-6 months pregnancy.Following removal of the dorsal root ganglion perineurium,the gan-glia were dissected into tiny pieces and digested with 0.2% collagenase and 0.25% trypsin (volume ratio 1:1),then explanted and cultured.SC purification was performed with 5 mL 10% fetal bovine serum added to the culture media,followed by differential adhesion.MAIN OUTCOME MEASURES:SCs morphology was observed under inverted phase contrast light microscopy.SC purity was evaluated according to percentage of S-100 immunostained cells.RESULTS:SCs were primarily cultured for 5-6 days and then subcultured for 4-5 passages.The highly enriched SC population reached > 95% purity and presented with normal morphology.CONCLUSION:A high purity of SCs was obtained with culture methods using human fetal dorsal root ganglion tissue explants.

  19. InGaP/GaAs heterojunction photosensor powered by an on-chip GaAs solar cell for energy harvesting

    Science.gov (United States)

    Than, Phuc Hong; Uchida, Kazuo; Makino, Takahiro; Ohshima, Takeshi; Nozaki, Shinji

    2016-04-01

    In this study, an InGaP/GaAs heterojunction phototransistor (HPT) and a GaAs solar cell were monolithically integrated into an HPT epitaxial wafer, and the battery-free operation of the HPT was demonstrated for energy harvesting. Although the thickness and doping condition of the layers were optimized for the HPT performance, but not for the solar cell performance, the obtained short-circuit current was high enough to operate the InGaP/GaAs HPT in a two-terminal (2T) configuration. A collector photocurrent of 0.63 mA was obtained when the energy-harvesting InGaP/GaAs 2T-HPT was exposed to white light with a power density of 35 mW/cm2, and it linearly increased with the power density. For a potential application of the energy-harvesting InGaP/GaAs HPT as a photosensor in space, the device was irradiated with electrons of 1 MeV energy and 1015 cm-2 fluence. No significant degradation of the fabricated energy-harvesting 2T-HPT after the high-energy electron irradiation guarantees its battery-free operation in space.

  20. Growth and Plating of Cell Suspension Cultures of Datura Innoxia

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen

    1974-01-01

    Suspension cultures of Datura innoxia Mill, were successfully grown on a modified Murashige and Skoog medium with 2,4–D, NAA or BAP as growth substances, provided the micronutrient levels were reduced to 1/10. Normal amounts of micronutrients were toxic. Attempts to identify the toxic elements did...... malate) or on NO3−-N alone. Dry weight yield was proportional to the amount of nitrate-N added (47 mg/mg N). Filtered suspension cultures containing single cells (plating cultures) could be grown in agar in petri dishes when NAA or 2,4-D were used as growth substances. Cells grew at densities above 500...... units/ml in the agar. Most colonies grew from cell aggregates but division in single cells was observed. The highest plating efficiency was about 50% on 10−6 M 2,4-D + 1 g/1 casein hydrolysate....

  1. Cloning higher plants from aseptically cultured tissues and cells

    Science.gov (United States)

    Krikorian, A. D.

    1982-01-01

    A review of aseptic culture methods for higher plants is presented, which focuses on the existing problems that limit or prevent the full realization of cloning plants from free cells. It is shown that substantial progress in clonal multiplication has been made with explanted stem tips or lateral buds which can be stimulated to produce numerous precocious axillary branches. These branches can then be separated or subdivided and induced to root in order to yield populations of genetically and phenotypically uniorm plantlets. Similarly, undifferentiated calluses can sometimes be induced to form shoots and/or roots adventitiously. Although the cell culture techniques required to produce somatic embryos are presently rudimentary, steady advances are being made in learning how to stimulate formation of somatic or adventive embryos from totipotent cells grown in suspension cultures. It is concluded that many problems exist in the producing and growing of totipotent or morphogenetically competent cell suspensions, but the potential benefits are great.

  2. Miniature Bioreactor System for Long-Term Cell Culture

    Science.gov (United States)

    Gonda, Steve R.; Kleis, Stanley J.; Geffert, Sandara K.

    2010-01-01

    A prototype miniature bioreactor system is designed to serve as a laboratory benchtop cell-culturing system that minimizes the need for relatively expensive equipment and reagents and can be operated under computer control, thereby reducing the time and effort required of human investigators and reducing uncertainty in results. The system includes a bioreactor, a fluid-handling subsystem, a chamber wherein the bioreactor is maintained in a controlled atmosphere at a controlled temperature, and associated control subsystems. The system can be used to culture both anchorage-dependent and suspension cells, which can be either prokaryotic or eukaryotic. Cells can be cultured for extended periods of time in this system, and samples of cells can be extracted and analyzed at specified intervals. By integrating this system with one or more microanalytical instrument(s), one can construct a complete automated analytical system that can be tailored to perform one or more of a large variety of assays.

  3. Culture of isolated single cells from Taxus suspensions for the propagation of superior cell populations.

    Science.gov (United States)

    Naill, Michael C; Roberts, Susan C

    2005-11-01

    Single cells isolated from aggregated Taxus cuspidata cultures via enzymatic digestion were grown in suspension culture. High seeding density (4 x 10(5 )cells/ml) and the addition of cell-free conditioned medium were essential for growth. Doubling the concentration of the nutrients [ascorbic acid (150 g/l), glutamine (6.25 mM: ), and citric acid (150 g/l)] had no effect on single cell growth or viability. A specific growth rate of 0.11 days(-1) was achieved, which is similar to the observed growth rate of aggregated Taxus suspensions. The biocide, Plant Preservative Mixture, added at 0.2% (v/v) to all single cell cultures to prevent microbial contamination, had no significant effect on growth or viability. Following cell sorting, single cell cultures can be used to establish new cell lines for biotechnology applications or provide cells for further study.

  4. Establishing a stem cell culture laboratory for clinical trials

    Directory of Open Access Journals (Sweden)

    Elíseo Joji Sekiya

    2012-01-01

    Full Text Available Adult stem/progenitor cells are found in different human tissues. An in vitro cell culture is needed for their isolation or for their expansion when they are not available in a sufficient quantity to regenerate damaged organs and tissues. The level of complexity of these new technologies requires adequate facilities, qualified personnel with experience in cell culture techniques, assessment of quality and clear protocols for cell production. The rules for the implementation of cell therapy centers involve national and international standards of good manufacturing practices. However, such standards are not uniform, reflecting the diversity of technical and scientific development. Here standards from the United States, the European Union and Brazil are analyzed. Moreover, practical solutions encountered for the implementation of a cell therapy center appropriate for the preparation and supply of cultured cells for clinical studies are described. Development stages involved the planning and preparation of the project, the construction of the facility, standardization of laboratory procedures and development of systems to prevent cross contamination. Combining the theoretical knowledge of research centers involved in the study of cells with the practical experience of blood therapy services that manage structures for cell transplantation is presented as the best potential for synergy to meet the demands to implement cell therapy centers.

  5. Cell death in mammalian cell culture: molecular mechanisms and cell line engineering strategies.

    Science.gov (United States)

    Krampe, Britta; Al-Rubeai, Mohamed

    2010-07-01

    Cell death is a fundamentally important problem in cell lines used by the biopharmaceutical industry. Environmental stress, which can result from nutrient depletion, by-product accumulation and chemical agents, activates through signalling cascades regulators that promote death. The best known key regulators of death process are the Bcl-2 family proteins which constitute a critical intracellular checkpoint of apoptosis cell death within a common death pathway. Engineering of several members of the anti-apoptosis Bcl-2 family genes in several cell types has extended the knowledge of their molecular function and interaction with other proteins, and their regulation of cell death. In this review, we describe the various modes of cell death and their death pathways at molecular and organelle level and discuss the relevance of the growing knowledge of anti-apoptotic engineering strategies to inhibit cell death and increase productivity in mammalian cell culture.

  6. Cell division and differentiation in protoplasts from cell cultures of Glycine species and leaf tissue of soybean.

    Science.gov (United States)

    Gamborg, O L; Davis, B P; Stahlhut, R W

    1983-08-01

    Protoplasts were isolated from cell cultures of G. soja and G. tabacina, respectively. The isolation procedure employed Percoll for the separation and concentration of protoplasts. The cultured protoplasts formed cells which developed into embryo-like structures. Protoplasts also were isolated from leaf tissue of soybean cv. Williams 82. Upon culture, the protoplasts regenerated cell walls and divided to form cell cultures.

  7. Cytopathogenicity of Naegleria for cultured neuroblastoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Fulford, D.E.

    1985-01-01

    The cytopathic activity of live Naegleria amoebae and cell-free lysates of Naegleria for B-103 rat neuroblastoma cells was investigated using a /sup 51/Cr release assay. Live amoebae and cell-free lysates of N. fowleri, N. australiensis, N. lovaniensis, and N. gruberi all induced sufficient damage to radiolabeled B-103 cells to cause a significant release of chromium. The cytotoxic activity present in the cell-free lysates of N. fowleri can be recovered in the supernatant fluid following centrifugation at 100,000xg and precipitation of the 100,000xg supernatant fluid with ammonium sulfate. Initial characterization of the cytotoxic factor indicates that it is a heat labile, pH sensitive, soluble protein. The cytotoxic activity is abolished by either extraction, unaffected by repeated freeze-thawing, and is not sensitive to inhibitors of proteolytic enzymes. Phospholipase A activity was detected in the cytotoxic ammonium sulfate precipitable material, suggesting that this enzyme activity may have a role in the cytotoxic activity of the cell-free lysates.

  8. Resonant cavity enhanced light harvesting in flexible thin-film organic solar cells.

    Science.gov (United States)

    Sergeant, Nicholas P; Niesen, Bjoern; Liu, Albert S; Boman, Lee; Stoessel, Chris; Heremans, Paul; Peumans, Peter; Rand, Barry P; Fan, Shanhui

    2013-05-01

    Dielectric/metal/dielectric (DMD) electrodes have the potential to significantly increase the absorption efficiency and photocurrent in flexible organic solar cells. We demonstrate that this enhancement is attributed to a broadband cavity resonance. Silver-based semitransparent DMD electrodes with sheet resistances below 10 ohm/sq. are fabricated on flexible polyethylene terephthalate (PET) substrates in a high-throughput roll-to-roll sputtering tool. We carefully study the effect of the semitransparent DMD electrode (here composed of Zn(x)Sn(y)O(z)/Ag/In(x)Sn(y)O(z)) on the optical device performance of a copper phthalocyanine (CuPc)/fullerene (C60) bilayer cell and illustrate that a resonant cavity enhanced light trapping effect dominates the optical behavior of the device.

  9. Temperature Field Analysis for PZT Pyroelectric Cells for Thermal Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Chi-Yuan Lee

    2011-11-01

    Full Text Available This paper proposes the idea of etching PZT to improve the temperature variation rate of a thicker PZT sheet in order to enhance the energy conversion efficiency when used as pyroelectric cells. A partially covered electrode was proven to display a higher output response than a fully covered electrode did. A mesh top electrode monitored the temperature variation rate and the electrode area. The mesh electrode width affected the distribution of the temperature variation rate in a thinner pyroelectric material. However, a pyroelectric cell with a thicker pyroelectric material was beneficial in generating electricity pyroelectrically. The PZT sheet was further etched to produce deeper cavities and a smaller electrode width to induce lateral temperature gradients on the sidewalls of cavities under homogeneous heat irradiation, enhancing the temperature variation rate.

  10. Resonant cavity enhanced light harvesting in flexible thin-film organic solar cells

    KAUST Repository

    Sergeant, Nicholas P.

    2013-04-24

    Dielectric/metal/dielectric (DMD) electrodes have the potential to significantly increase the absorption efficiency and photocurrent in flexible organic solar cells. We demonstrate that this enhancement is attributed to a broadband cavity resonance. Silver-based semitransparent DMD electrodes with sheet resistances below 10 ohm/sq. are fabricated on flexible polyethylene terephthalate (PET) substrates in a high-throughput roll-to-roll sputtering tool. We carefully study the effect of the semitransparent DMD electrode (here composed of ZnxSnyOz/Ag/InxSn yOz) on the optical device performance of a copper phthalocyanine (CuPc)/fullerene (C60) bilayer cell and illustrate that a resonant cavity enhanced light trapping effect dominates the optical behavior of the device. © 2013 Optical Society of America.

  11. Functionalized zinc porphyrin as light harvester in dye sensitized solar cells

    Indian Academy of Sciences (India)

    L Giribabu; Ch Vijay Kumar; M Raghavender; K Somaiah; P Yella Reddy; P Venkateswara Rao

    2008-09-01

    A new photosensitizer having two rhodanine acetic acid groups at meso-positions of a zinc porphyrin [meso-Rhod-Zn-Rhod] has been synthesized and characterized by UV-Visible, 1H NMR, MALDI-MS, fluorescence spectroscopies and cyclic voltammetry. The new photosensitizer was tested in dye-sensitized solar cells with three different liquid redox electrolytes and compared its efficiency () with dyad. Both dyad and triad were also tested in DSSC using a polymer gel redox electrolyte and observed low efficiency because of small short circuiting current i.e. ISc though the IPCE is significantly high. The probable reason for the low efficiency small ISc has been attributed to the internal resistance of the cell.

  12. Low Illumination Light (LIL) Solar Cells: Indoor and Monochromatic Light Harvesting

    Science.gov (United States)

    2015-11-01

    instrumentation , and sensors handbook Second Edition: Spatial, mechanical, thermal, and radiation measurement , Boca Raton (FL). CRC Press Taylor...Phosphor Components Used in Report 37 iv Appendix C. Quantum Efficiency Measurements of Single-Junction Solar Cells 41 Appendix D...575, and 600 nm. All have the same relative intensities between 470 to 500 nm. ...........39 Fig. C-1 QE measurements of single-junction PV solar

  13. The replacement of serum by hormones in cell culture media.

    Science.gov (United States)

    Sato, G; Hayashi, I

    1976-12-01

    The replacement of serum by hormones in cell culture media. (Reemplazo del suero por hormonas en el medio de cultivo de células). Arch. Biol. Med. Exper. 10: 120-121, 1976. The serum used in cell culture media can be replaced by a mixture of hormones and some accesory blood factors. The pituitary cell line GH3 can be grown in a medium in which serum is replaced by triiodothyronine, transferrin, parathormone, tyrotrophin releasing hormone and somatomedins. Hela and BHK cell strains can also be grown in serum free medium supplemented with hormones. Each cell type appears to have different hormonal requirements yet it may found that some hormones are required for most cell types.

  14. The role of community engagement in the adoption of new agricultural biotechnologies by farmers: the case of the Africa harvest tissue-culture banana in Kenya.

    Science.gov (United States)

    Bandewar, Sunita V S; Wambugu, Florence; Richardson, Emma; Lavery, James V

    2017-03-13

    The tissue culture banana (TCB) is a biotechnological agricultural innovation that has been adopted widely in commercial banana production. In 2003, Africa Harvest Biotech Foundation International (AH) initiated a TCB program that was explicitly developed for smallholder farmers in Kenya to help them adopt the TCB as a scalable agricultural business opportunity. At the heart of the challenge of encouraging more widespread adoption of the TCB is the question: what is the best way to introduce the TCB technology, and all its attendant practices and opportunities, to smallholder farmers. In essence, a challenge of community or stakeholder engagement (CE). In this paper, we report the results of a case study of the CE strategies employed by AH to introduce TCB agricultural practices to small-hold farmers in Kenya, and their impact on the uptake of the TCB, and on the nature of the relationship between AH and the relevant community of farmers and other stakeholders. We identified six specific features of CE in the AH TCB project that were critical to its effectiveness: (1) adopting an empirical, "evidence-based" approach; (2) building on existing social networks; (3) facilitating farmer-to-farmer engagement; (4) focusing engagement on farmer groups; (5) strengthening relationships of trust through collaborative experiential learning; and (6) helping farmers to "learn the marketing game". We discuss the implications of AH's "values-based" approach to engagement, and how these guiding values functioned as "design constraints" for the key features of their CE strategy. And we highlight the importance of attention to the human dimensions of complex partnerships as a key determinant of successful CE. Our findings suggest new ways of conceptualizing the relationship between CE and the design and delivery of new technologies for global health and global development.

  15. Isolation and Culture of Human Endothelial Cells from Micro- and Macro-vessels.

    Science.gov (United States)

    Hewett, Peter W

    2016-01-01

    The endothelium from different vascular beds exhibits a high degree of phenotypic heterogeneity. Endothelial cells (EC) can be harvested easily from large vessels by mechanical removal or collagenase digestion. In particular, the human umbilical vein has been used due to its wide availability, and the study of ECs derived from it has undoubtedly greatly advanced our knowledge of vascular biology. However, the majority of the body's endothelium (>95 %) forms the microvasculature, and it is these cells providing the interface between the blood and tissues that play a critical role in the development of new blood vessels. This has led to the establishment of techniques for the isolation of microvascular ECs (MEC) from different tissues to provide more physiologically relevant in vitro models of angiogenesis and EC function.In this chapter the use of superparamagnetic beads (Dynabeads) coated with anti-PECAM-1 (CD31) antibodies (PECA-beads) to culture MECs from human adipose tissue is described along with the standard methods used to characterize them. Adipose tissue is an ideal source of MECs as it is composed mainly of adipocytes with a very rich microvasculature and is easy to disaggregate. Furthermore, it can be obtained in large quantities during plastic surgery procedures. Adipose obtained at reduction mammoplasty or abdominoplasty is first dissected free of the connective tissue, minced finely, and subjected to collagenase type II digestion. The adipocytes are removed by centrifugation to obtain a microvessel rich pellet, which is further disaggregated with trypsin/EDTA solution. Following filtration to remove fragments of the connective tissue, the pellet is incubated with PECA-beads and microvessel fragments/ECs and washed and harvested using a magnet. In addition, the adaptation of this basic technique for the isolation of the human lung and stomach MECs is also described along with common methods for the preparation of large vessel endothelial cells.

  16. Foetal hepatic progenitor cells assume a cholangiocytic cell phenotype during two-dimensional pre-culture.

    Science.gov (United States)

    Anzai, Kazuya; Chikada, Hiromi; Tsuruya, Kota; Ida, Kinuyo; Kagawa, Tatehiro; Inagaki, Yutaka; Mine, Tesuya; Kamiya, Akihide

    2016-06-23

    Liver consists of parenchymal hepatocytes and other cells. Liver progenitor cell (LPC) is the origin of both hepatocytes and cholangiocytic cells. The analyses of mechanism regulating differentiation of LPCs into these functional cells are important for liver regenerative therapy using progenitor cells. LPCs in adult livers were found to form cysts with cholangiocytic characteristics in 3D culture. In contrast, foetal LPCs cannot form these cholangiocytic cysts in the same culture. Thus, the transition of foetal LPCs into cholangiocytic progenitor cells might occur during liver development. Primary CD45(-)Ter119(-)Dlk1(+) LPCs derived from murine foetal livers formed ALBUMIN (ALB)(+)CYTOKERATIN (CK)19(-) non-cholangiocytic cysts within 3D culture. In contrast, when foetal LPCs were pre-cultured on gelatine-coated dishes, they formed ALB(-)CK19(+) cholangiocytic cysts. When hepatocyte growth factor or oncostatin M, which are inducers of hepatocytic differentiation, was added to pre-culture, LPCs did not form cholangiocytic cysts. These results suggest that the pre-culture on gelatine-coated dishes changed the characteristics of foetal LPCs into cholangiocytic cells. Furthermore, neonatal liver progenitor cells were able to form cholangiocytic cysts in 3D culture without pre-culture. It is therefore possible that the pre-culture of mid-foetal LPCs in vitro functioned as a substitute for the late-foetal maturation step in vivo.

  17. Differential heat shock response of primary human cell cultures and established cell lines

    DEFF Research Database (Denmark)

    Richter, W W; Issinger, O G

    1986-01-01

    degrees C treatment, whereas in immortalized cell lines usually 90% of the cells were found in suspension. Enhanced expression of the major heat shock protein (hsp 70) was found in all heat-treated cells. In contrast to the primary cell cultures, established and transformed cell lines synthesized...

  18. Wave characterization for mammalian cell culture: residence time distribution.

    Science.gov (United States)

    Rodrigues, Maria Elisa; Costa, Ana Rita; Henriques, Mariana; Azeredo, Joana; Oliveira, Rosário

    2012-02-15

    The high dose requirements of biopharmaceutical products led to the development of mammalian cell culture technologies that increase biomanufacturing capacity. The disposable Wave bioreactor is one of the most promising technologies, providing ease of operation and no cross-contamination, and using an innovative undulation movement that ensures good mixing and oxygen transfer without cell damage. However, its recentness demands further characterization. This study evaluated the residence time distribution (RTD) in Wave, allowing the characterization of mixing and flow and the comparison with ideal models and a Stirred tank reactor (STR) used for mammalian cell culture. RTD was determined using methylene blue with pulse input methodology, at three flow rates common in mammalian cell culture (3.3×10(-5)m(3)/h, 7.9×10(-5)m(3)/h, and 1.25×10(-4)m(3)/h) and one typical of microbial culture (5×10(-3)m(3)/h). Samples were taken periodically and the absorbance read at 660nm. It was observed that Wave behavior diverted from ideal models, but was similar to STR. Therefore, the deviations are not related to the particular Wave rocking mechanism, but could be associated with the inadequacy of these reactors to operate in continuous mode or to a possible inability of the theoretical models to properly describe the behavior of reactors designed for mammalian cell culture. Thus, the development of new theoretical models could better characterize the performance of these reactors.

  19. Isolation and Culture of Postnatal Stem Cells from Deciduous Teeth

    OpenAIRE

    Olávez, Daniela; Facultad de Odontología Universidad de Los Andes; Salmen, Siham; Instituto de Inmunología Clínica, Universidad de Los Andes.; Padrón, Karla; Facultad de Odontología. Univerisdad de Los Andes.; Lobo, Carmine; Facultad de Odontología. Univerisdad de Los Andes.; Díaz, Nancy; Facultad de Odontología, Universidad de Los Andes.; Berrueta, Lisbeth; Doctora en Inmunología por Instituto Venezolano de Investigaciones Científicas (IVIC). Instituto de Inmunología Clínica, Facultad de Medicina, Universidad de Los Andes, Venezuela.; Solorzanio, Eduvigis; Facultad de Odontología, Universidad de Los Andes.

    2014-01-01

    Background: Currently, degenerative diseases represent a public health problem; therefore, the development and implementation of strategies to fully or partially recover of damaged tissues has a special interest in the biomedical field. Therapeutic strategies based on mesenchymal stem cells transplantation from dental pulp have been proposed as an alternative. Purpose: To develop a mesenchymal stem cells culture isolated from dental pulp of deciduous teeth. Methods: The mesenchymal stem cells...

  20. Culture of Neural Stem Cells in Calcium-alginate Microbeads

    Institute of Scientific and Technical Information of China (English)

    Li-Song YAO; Tian-Qing LIU; Dan GE; Xue-Hu MA; Zhan-Feng CUI

    2005-01-01

    @@ 1 Introduction Recent research shows that neural stem cells may play an important role in the nerve injury reparation and nerve disease treatment. The shortage of the source and the number of NSCs, however, is the main challenge for its clinic application. In this situation, expansion of NSCs in large scale and culture in three dimensional environment are very worth of exploration. Notablely, the shear stress existed in bioreactors can cause serious cell injury especially for the shear sensitive cells like NSCs.

  1. Isolation and Culture of Postnatal Stem Cells from Deciduous Teeth

    OpenAIRE

    Olávez, Daniela; Facultad de Odontología Universidad de Los Andes; Salmen, Siham; Instituto de Inmunología Clínica, Universidad de Los Andes.; Padrón, Karla; Facultad de Odontología. Univerisdad de Los Andes.; Lobo, Carmine; Facultad de Odontología. Univerisdad de Los Andes.; Díaz, Nancy; Facultad de Odontología, Universidad de Los Andes.; Berrueta, Lisbeth; Doctora en Inmunología por Instituto Venezolano de Investigaciones Científicas (IVIC). Instituto de Inmunología Clínica, Facultad de Medicina, Universidad de Los Andes, Venezuela.; Solorzanio, Eduvigis; Facultad de Odontología, Universidad de Los Andes.

    2014-01-01

    Background: Currently, degenerative diseases represent a public health problem; therefore, the development and implementation of strategies to fully or partially recover of damaged tissues has a special interest in the biomedical field. Therapeutic strategies based on mesenchymal stem cells transplantation from dental pulp have been proposed as an alternative. Purpose: To develop a mesenchymal stem cells culture isolated from dental pulp of deciduous teeth. Methods: The mesenchymal stem cells...

  2. Isolation, Culture, Differentiation, and Nuclear Reprogramming of Mongolian Sheep Fetal Bone Marrow-Derived Mesenchymal Stem Cells.

    Science.gov (United States)

    Su, Xiaohu; Ling, Yu; Liu, Chunxia; Meng, Fanhua; Cao, Junwei; Zhang, Li; Zhou, Huanmin; Liu, Zongzheng; Zhang, Yanru

    2015-08-01

    We have characterized the differentiation potentiality and the developmental potential of cloned embryos of fetal bone marrow mesenchymal stem cells (BMSCs) isolated from Mongolian sheep. BMSCs were harvested by centrifuging after the explants method and the mononuclear cells obtained were cultured. The isolated BMSCs were uniform, with a fibroblast-like spindle or stellate appearance, and we confirmed expression of OCT4, SOX2, and NANOG genes at passage 3 (P3) by RT-PCR. We measured the growth of the passage 1, 5, and 10 cultures and found exponential growth with a population doubling time of 29.7±0.05 h. We cultured the P3 BMSCs in vitro under inductive environments and were able to induce them to undergo neurogenesis and form cardiomyocytes and adipocytes. Donor cells at passages 3-4 were used for nuclear transfer (NT). We found the BMSCs could be expanded in vitro and used as nuclear donors for somatic cell nuclear transfer (SCNT). Thus, BMSCs are an attractive cell type for large-animal autologous studies and will be valuable material for somatic cell cloning and future transgenic research.

  3. A novel closed cell culture device for fabrication of corneal epithelial cell sheets.

    Science.gov (United States)

    Nakajima, Ryota; Kobayashi, Toyoshige; Moriya, Noboru; Mizutani, Manabu; Kan, Kazutoshi; Nozaki, Takayuki; Saitoh, Kazuo; Yamato, Masayuki; Okano, Teruo; Takeda, Shizu

    2015-11-01

    Automation technology for cell sheet-based tissue engineering would need to optimize the cell sheet fabrication process, stabilize cell sheet quality and reduce biological contamination risks. Biological contamination must be avoided in clinical settings. A closed culture system provides a solution for this. In the present study, we developed a closed culture device called a cell cartridge, to be used in a closed cell culture system for fabricating corneal epithelial cell sheets. Rabbit limbal epithelial cells were cultured on the surface of a porous membrane with 3T3 feeder cells, which are separate from the epithelial cells in the cell cartridges and in the cell-culture inserts as a control. To fabricate the stratified cell sheets, five different thicknesses of the membranes which were welded to the cell cartridge, were examined. Multilayered corneal epithelial cell sheets were fabricated in cell cartridges that were welded to a 25 µm-thick gas-permeable membrane, which was similar to the results with the cell-culture inserts. However, stratification of corneal epithelial cell sheets did not occur with cell cartridges that were welded to 100-300 µm-thick gas-permeable membranes. The fabricated cell sheets were evaluated by histological analyses to examine the expression of corneal epithelial-specific markers. Immunohistochemical analyses showed that a putative stem cell marker, p63, a corneal epithelial differentiation maker, CK3, and a barrier function marker, Claudin-1, were expressed in the appropriate position in the cell sheets. These results suggest that the cell cartridge is effective for fabricating corneal epithelial cell sheets.

  4. Screening π-conjugated bridges of organic dyes for dye-sensitized solar cells with panchromatic visible light harvesting

    Science.gov (United States)

    Yang, Zhenqing; Liu, Chunmeng; Shao, Changjin; Zeng, Xiaofei; Cao, Dapeng

    2016-07-01

    Developing highly efficient organic dyes with panchromatic visible light harvesting for dye-sensitized solar cells (DSSCs) is still one of the most important scientific challenges. Here, we design a series of phenothiazine derivative organic dyes with donor-π-acceptor (D-π-A) structure using density functional theory (DFT) and time-dependent DFT (TDDFT) based on experimentally synthesized typical SH-6 organic dyes. Results indicate that the newly designed BUCT13 - BUCT30 dyes show smaller HOMO-LUMO energy gaps, higher molar extinction coefficients and obvious redshifts compared to the SH-6 dye, and the maximum absorption peaks of eight dyes are greater than 650 nm among the newly designed dyes. In particular, BUCT27 exhibits a 234 nm redshift and the maximum molar extinction coefficient with an increment of about 80% compared to the SH-6 dye. BUCT19 exhibits not only a 269 nm redshift and higher molar extinction coefficient with an increment of about 50% compared to the SH-6 dye, but the extremely broad absorption spectrum covering the entire visible range up to the near-IR region of 1200 nm. It is expected that this work can provide a new strategy and guidance for the investigation of these dye-sensitized devices.

  5. Ruthenium based metallopolymer grafted reduced graphene oxide as a new hybrid solar light harvester in polymer solar cells

    Science.gov (United States)

    Vinoth, R.; Babu, S. Ganesh; Bharti, Vishal; Gupta, V.; Navaneethan, M.; Bhat, S. Venkataprasad; Muthamizhchelvan, C.; Ramamurthy, Praveen C.; Sharma, Chhavi; Aswal, Dinesh K.; Hayakawa, Yasuhiro; Neppolian, B.

    2017-01-01

    A new class of pyridyl benzimdazole based Ru complex decorated polyaniline assembly (PANI-Ru) was covalently grafted onto reduced graphene oxide sheets (rGO) via covalent functionalization approach. The covalent attachment of PANI-Ru with rGO was confirmed from XPS analysis and Raman spectroscopy. The chemical bonding between PANI-Ru and rGO induced the electron transfer from Ru complex to rGO via backbone of the conjugated PANI chain. The resultant hybrid metallopolymer assembly was successfully demonstrated as an electron donor in bulk heterojunction polymer solar cells (PSCs). A PSC device fabricated with rGO/PANI-Ru showed an utmost ~6 fold and 2 fold enhancement in open circuit potential (Voc) and short circuit current density (Jsc) with respect to the standard device made with PANI-Ru (i.e., without rGO) under the illumination of AM 1.5 G. The excellent electronic properties of rGO significantly improved the electron injection from PANI-Ru to PCBM and in turn the overall performance of the PSC device was enhanced. The ultrafast excited state charge separation and electron transfer role of rGO sheet in hybrid metallopolymer was confirmed from ultrafast spectroscopy measurements. This covalent modification of rGO with metallopolymer assembly may open a new strategy for the development of new hybrid nanomaterials for light harvesting applications. PMID:28225039

  6. A biocompatible micro cell culture chamber (microCCC) for the culturing and on-line monitoring of eukaryote cells

    DEFF Research Database (Denmark)

    Stangegaard, Michael; Petronis, Sarunas; Jørgensen, A M

    2006-01-01

    We have previously shown that a polymeric (PMMA) chip with medium perfusion and integrated heat regulation provides sufficiently precise heat regulation, pH-control and medium exchange to support cell growth for weeks. However, it was unclear how closely the cells cultured in the chip resembled c...

  7. Experiments on tissue culture in the genus Lycopersicon miller : Shoot formation from protoplasts of tomato long-term cell cultures.

    Science.gov (United States)

    Koblitz, H; Koblitz, D

    1982-06-01

    Callus cultures from cotyledon explants were established and maintained in culture for more than two years. After several months callus cultures were transferred into liquid medium and cultured as cell suspensions. Protoplasts were isolated from these cell suspension cultures and cultured in a liquid medium. After formation of new cell walls the cells were further cultured in liquid medium and afterwards transferred to an agar-solidified medium to give a vigorously growing callus culture. In the case of the cultivar 'Lukullus' shoots were recovered from callus. All efforts to root these shoots failed and this, in addition to variations in appearence, suggests that the shoots are changed genetically possibly due to the prolonged culture period.

  8. Comparison of human nasal epithelial cells grown as explant outgrowth cultures or dissociated tissue cultures in vitro.

    Science.gov (United States)

    Jiao, Jian; Meng, Na; Wang, Hong; Zhang, Luo

    2013-12-01

    The purpose of this study was to compare cell growth characteristics, ciliated cell differentiation, and function of human nasal epithelial cells established as explant outgrowth cultures or dissociated tissue cultures. Human nasal mucosa of the uncinate process was obtained by endoscopy and epithelial cell cultures were established by explant outgrowth or dissociated tissue culture methods. Epithelial cell growth characteristics were observed by inverted phase contrast microscopy. Ciliated cell differentiation was detected by β-tubulin IVand ZO-1 immunocytochemistry. Basal and ATP-stimulated ciliary beat frequency (CBF) was measured using a highspeed digital microscopic imaging system. Both the explant and dissociated tissue cultures established as monolayers with tight junctions and differentiated cell composition, with both types of cultures comprising ciliated and non-ciliated epithelial cells. Fibroblasts were also frequently found in explant cultures but rarely seen in dissociated tissue cultures. In both culture systems, the highest ciliated cell density appeared at 7th-10th culture day and declined with time, with the lifespan of ciliated cells ranging from 14 to 21 days. Overall, 10% of the cells in explant cultures and 20% of the cells in the dissociated tissue cultures were ciliated. These two cultures demonstrated similar ciliary beat frequency values at baseline (7.78 ± 1.99 Hz and 7.91 ± 2.52 Hz, respectively) and reacted equivalently following stimulation with 100 μM ATP. The results of this study indicate that both the explant outgrowth and dissociated tissue culture techniques are suitable for growing well-differentiated nasal ciliated and non-ciliated cells, which have growth characteristics and ciliary activity similar to those of nasal epithelial cells in vivo.

  9. Metabolic measurements in cell culture and tissue constructs

    Science.gov (United States)

    Rolfe, P.

    2008-10-01

    This paper concerns the study and use of biological cells in which there is a need for sensors and assemblies for the measurement of a diverse range of physical and chemical variables. In this field cell culture is used for basic research and for applications such as protein and drug synthesis, and in cell, tissue and organ engineering. Metabolic processes are fundamental to cell behaviour and must therefore be monitored reliably. Basic metabolic studies measure the transport of oxygen, glucose, carbon dioxide, lactic acid to, from, or within cells, whilst more advanced research requires examination of energy storage and utilisation. Assemblies are designed to incorporate bioreactor functions for cell culture together with appropriate sensing devices. Oxygen consumption by populations of cells is achieved in a flowthrough assembly that incorporates O2 micro-sensors based on either amperometry or fluorescence. Measurements in single cell are possible with intra-cellular fluorophores acting as biosensors together with optical stimulation and detection. Near infra-red spectroscopy (NIRS) is used for analysis within culture fluid, for example for estimation of glucose levels, as well as within cell populations, for example to study the respiratory enzymes.Â#

  10. Cellular interactions regulate stem cell differentiation in tri-culture.

    Science.gov (United States)

    Wang, I-Ning E; Bogdanowicz, Danielle R; Mitroo, Siddarth; Shan, Jing; Kala, Sonam; Lu, Helen H

    2016-11-01

    Currently, the mechanism governing the regeneration of the soft tissue-to-bone interface, such as the transition between the anterior cruciate ligament (ACL) and bone, is not known. Focusing on the ACL-to-bone insertion, this study tests the novel hypothesis that interactions between cells from the ligament (fibroblasts) and bone (osteoblasts) initiate interface regeneration. Specifically, these heterotypic cell interactions direct the fibrochondrogenic differentiation of interface-relevant cell populations, defined here as ligament fibroblasts and bone marrow stromal cells (BMSC). The objective of this study is to examine the effects of heterotypic cellular interactions on BMSC or fibroblast growth and biosynthesis, as well as expression of fibrocartilage-relevant markers in tri-culture. The effects of cell-cell physical contact and paracrine interactions between fibroblasts and osteoblasts were also determined. It was found that, in tri-culture with fibroblasts and osteoblasts, BMSC exhibited greater fibrochondrogenic potential than ligament fibroblasts. The growth of BMSC decreased while proteoglycan production and TGF-β3 expression increased. Moreover, tri-culture regulated BMSC response via paracrine factors, and interestingly, fibroblast-osteoblast contact further promoted proteoglycan and TGF-β1 synthesis as well as induced SOX9 expression in BMSC. Collectively, the findings of this study suggest that fibroblast-osteoblast interactions play an important role in regulating the stem cell niche for fibrocartilage regeneration, and the mechanisms of these interactions are directed by paracrine factors and augmented with direct cell-cell contact.

  11. Hydroxyapatite incorporated into collagen gels for mesenchymal stem cell culture.

    Science.gov (United States)

    Laydi, F; Rahouadj, R; Cauchois, G; Stoltz, J-F; de Isla, N

    2013-01-01

    Collagen gels could be used as carriers in tissue engineering to improve cell retention and distribution in the defect. In other respect hydroxyapatite could be added to gels to improve mechanical properties and regulate gel contraction. The aim of this work was to analyze the feasibility to incorporate hydroxyapatite into collagen gels and culture mesenchymal stem cells inside it. Human bone marrow mesenchymal stem cells (hMSC-BM) were used in this study. Gels were prepared by mixing rat tail type I collagen, hydroxyapatite microparticles and MSCs. After polymerization gels were kept in culture while gel contraction and mechanical properties were studied. In parallel, cell viability and morphology were analyzed. Gels became free-floating gels contracted from day 3, only in the presence of cells. A linear rapid contraction phase was observed until day 7, then a very slow contraction phase took place. The incorporation of hydroxyapatite improved gel stability and mechanical properties. Cells were randomly distributed on the gel and a few dead cells were observed all over the experiment. This study shows the feasibility and biocompatibility of hydroxyapatite supplemented collagen gels for the culture of mesenchymal stem cells that could be used as scaffolds for cell delivery in osteoarticular regenerative medicine.

  12. Specimen Sample Preservation for Cell and Tissue Cultures

    Science.gov (United States)

    Meeker, Gabrielle; Ronzana, Karolyn; Schibner, Karen; Evans, Robert

    1996-01-01

    The era of the International Space Station with its longer duration missions will pose unique challenges to microgravity life sciences research. The Space Station Biological Research Project (SSBRP) is responsible for addressing these challenges and defining the science requirements necessary to conduct life science research on-board the International Space Station. Space Station will support a wide range of cell and tissue culture experiments for durations of 1 to 30 days. Space Shuttle flights to bring experimental samples back to Earth for analyses will only occur every 90 days. Therefore, samples may have to be retained for periods up to 60 days. This presents a new challenge in fresh specimen sample storage for cell biology. Fresh specimen samples are defined as samples that are preserved by means other than fixation and cryopreservation. The challenge of long-term storage of fresh specimen samples includes the need to suspend or inhibit proliferation and metabolism pending return to Earth-based laboratories. With this challenge being unique to space research, there have not been any ground based studies performed to address this issue. It was decided hy SSBRP that experiment support studies to address the following issues were needed: Fixative Solution Management; Media Storage Conditions; Fresh Specimen Sample Storage of Mammalian Cell/Tissue Cultures; Fresh Specimen Sample Storage of Plant Cell/Tissue Cultures; Fresh Specimen Sample Storage of Aquatic Cell/Tissue Cultures; and Fresh Specimen Sample Storage of Microbial Cell/Tissue Cultures. The objective of these studies was to derive a set of conditions and recommendations that can be used in a long duration microgravity environment such as Space Station that will permit extended storage of cell and tissue culture specimens in a state consistent with zero or minimal growth, while at the same time maintaining their stability and viability.

  13. 40 CFR 798.5300 - Detection of gene mutations in somatic cells in culture.

    Science.gov (United States)

    2010-07-01

    ... cells in culture. 798.5300 Section 798.5300 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY....5300 Detection of gene mutations in somatic cells in culture. (a) Purpose. Mammalian cell culture... selected by resistance to ouabain. (2) Description. Cells in suspension or monolayer culture are exposed to...

  14. 21 CFR 864.2240 - Cell and tissue culture supplies and equipment.

    Science.gov (United States)

    2010-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Cell And Tissue Culture Products § 864.2240 Cell and tissue culture supplies and equipment. (a) Identification. Cell and tissue culture... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cell and tissue culture supplies and...

  15. Effects of diluents on cell culture viability measured by automated cell counter

    National Research Council Canada - National Science Library

    Aaron Chen; Matthew Leith; Roger Tu; Gurpreet Tahim; Anish Sudra; Swapnil Bhargava

    2017-01-01

      Commercially available automated cell counters based on trypan blue dye-exclusion are widely used in industrial cell culture process development and manufacturing to increase throughput and eliminate...

  16. Therapeutic angiogenesis by a myoblast layer harvested by tissue transfer printing from cell-adhesive, thermosensitive hydrogels.

    Science.gov (United States)

    Kim, Dong Wan; Jun, Indong; Lee, Tae-Jin; Lee, Ji Hye; Lee, Young Jun; Jang, Hyeon-Ki; Kang, Seokyung; Park, Ki Dong; Cho, Seung-Woo; Kim, Byung-Soo; Shin, Heungsoo

    2013-11-01

    Peripheral arterial disease (PAD) is characterized by the altered structure and function of arteries caused by accumulated plaque. There have been many studies on treating this disease by the direct injection of various types of therapeutic cells, however, the low cell engraftment efficiency and diffusion of the transplanted cells have been major problems. In this study, we developed an approach (transfer printing) to deliver monolayer of cells to the hindlimb ischemic tissue using thermosensitive hydrogels, and investigated its efficacy in long term retention upon transplantation and therapeutic angiogenesis. We first investigated the in vitro maintenance of robust cell-cell contacts and stable expression of the ECM proteins in myoblast layer following transfer printing process. In order to confirm the therapeutic effect of the myoblasts in vivo, we cultured a monolayer of C2C12 myoblasts on thermosensitive hydrogels, which was then transferred to the hindlimb ischemia tissue of athymic mice directly from the hydrogel by conformal contact. The transferred myoblast layer was retained for a longer period of time than an intramuscularly injected cell suspension. In addition, the morphology of the mice and laser Doppler perfusion (28 days after treatment) supported that the myoblast layer enhanced the therapeutic effects on the ischemic tissue. In summary, the transplantation of the C2C12 myoblast layer using a tissue transfer printing method could represent a new approach for the treatment of PAD by therapeutic angiogenesis.

  17. Investigating why recycling gravity harvested algae increases harvestability and productivity in high rate algal ponds.

    Science.gov (United States)

    Park, J B K; Craggs, R J; Shilton, A N

    2013-09-15

    It has previously been shown that recycling gravity harvested algae promotes Pediastrum boryanum dominance and improves harvestability and biomass production in pilot-scale High Rate Algal Ponds (HRAPs) treating domestic wastewater. In order to confirm the reproducibility of these findings and investigate the mechanisms responsible, this study utilized twelve 20 L outdoor HRAP mesocosms operated with and without algal recycling. It then compared the recycling of separated solid and liquid components of the harvested biomass against un-separated biomass. The work confirmed that algal recycling promoted P. boryanum dominance, improved 1 h-settleability by >20% and increased biomass productivity by >25% compared with controls that had no recycling. With regard to the improved harvestability, of particular interest was that recycling the liquid fraction alone caused a similar improvement in settleability as recycling the solid fraction. This may be due to the presence of extracellular polymeric substances in the liquid fraction. While there are many possible mechanisms that could account for the increased productivity with algal recycling, all but two were systematically eliminated: (i) the mean cell residence time was extended thereby increasing the algal concentration and more fully utilizing the incident sunlight and, (ii) the relative proportions of algal growth stages (which have different specific growth rates) was changed, resulting in a net increase in the overall growth rate of the culture.

  18. Hollow fiber clinostat for simulating microgravity in cell culture

    Science.gov (United States)

    Rhodes, Percy H. (Inventor); Miller, Teresa Y. (Inventor); Snyder, Robert S. (Inventor)

    1992-01-01

    A clinostat for simulating microgravity on cell systems carried in a fiber fixedly mounted in a rotatable culture vessel is disclosed. The clinostat is rotated horizontally along its longitudinal axis to simulate microgravity or vertically as a control response. Cells are injected into the fiber and the ends of the fiber are sealed and secured to spaced end pieces of a fiber holder assembly which consists of the end pieces, a hollow fiber, a culture vessel, and a tension spring with three alignment pins. The tension spring is positioned around the culture vessel with its ends abutting the end pieces for alignment of the spring. After the fiber is secured, the spring is decompressed to maintain tension on the fiber while it is being rotated. This assures that the fiber remains aligned along the axis of rotation. The fiber assembly is placed in the culture vessel and culture medium is added. The culture vessel is then inserted into the rotatable portion of the clinostat and subjected to rotate at selected rpms. The internal diameter of the hollow fiber determines the distance the cells are from the axis of rotation.

  19. Experimental study of bioartificial liver with cultured human liver cells

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    AIM To establish an extracorporeal bioartificial liver support system (EBLSS) using cultured human liver cells and to study its support effect for fulminant hepatic failure (FHF).METHODS The liver support experiment of EBLSS consisting of aggregates cultured human liver cells, hollow fiber bioreactor, and circulation unit was carried out in dizhepatic dogs.RESULTS The viability of isolated hepatocytes and nonparenchymal liver cells reached 96%. These cells were successfully cultured as multicellular spheroids with synthetic technique. The typical morphological appearance was retained up to the end of the artificial liver experiment. Compared with the control dogs treated with EBLSS without liver cells, the survival time of artificial liver support dogs was significantly prolonged. The changes of blood pressure, heart rate and ECG were slow. Both serum ammonia and lactate levels were significantly lowered at the 3rd h and 5th h. In addition, a good viability of human liver cells was noted after 5 h experiment.CONCLUSION EBLSS playing a metabolic role of cultured human hepatocytes, is capable of compensating the function of the liver, and could provide effective artificial liver support and therapy for patients with FHF.

  20. Adult human brain cell culture for neuroscience research.

    Science.gov (United States)

    Gibbons, Hannah M; Dragunow, Mike

    2010-06-01

    Studies of the brain have progressed enormously through the use of in vivo and in vitro non-human models. However, it is unlikely such studies alone will unravel the complexities of the human brain and so far no neuroprotective treatment developed in animals has worked in humans. In this review we discuss the use of adult human brain cell culture methods in brain research to unravel the biology of the normal and diseased human brain. The advantages of using adult human brain cells as tools to study human brain function from both historical and future perspectives are discussed. In particular, studies using dissociated cultures of adult human microglia, astrocytes, oligodendrocytes and neurons are described and the applications of these types of study are evaluated. Alternative sources of human brain cells such as adult neural stem cells, induced pluripotent stem cells and slice cultures of adult human brain tissue are also reviewed. These adult human brain cell culture methods could benefit basic research and more importantly, facilitate the translation of basic neuroscience research to the clinic for the treatment of brain disorders. Copyright 2009 Elsevier Ltd. All rights reserved.

  1. "Humanized" stem cell culture techniques: the animal serum controversy.

    Science.gov (United States)

    Tekkatte, Chandana; Gunasingh, Gency Ponrose; Cherian, K M; Sankaranarayanan, Kavitha

    2011-01-01

    Cellular therapy is reaching a pinnacle with an understanding of the potential of human mesenchymal stem cells (hMSCs) to regenerate damaged tissue in the body. The limited numbers of these hMSCs in currently identified sources, like bone marrow, adipose tissue, and so forth, bring forth the need for their in vitro culture/expansion. However, the extensive usage of supplements containing xenogeneic components in the expansion-media might pose a risk to the post-transplantation safety of patients. This warrants the necessity to identify and develop chemically defined or "humanized" supplements which would make in vitro cultured/processed cells relatively safer for transplantation in regenerative medicine. In this paper, we outline the various caveats associated with conventionally used supplements of xenogenic origin and also portray the possible alternatives/additives which could one day herald the dawn of a new era in the translation of in vitro cultured cells to therapeutic interventions.

  2. [In vitro cell culture technology in cosmetology research].

    Science.gov (United States)

    Gojniczek, Katarzyna; Garncarczyk, Agnieszka; Pytel, Agata

    2005-01-01

    For ages the humanity has been looking for all kind of active substances, which could be used in improving the health and the appearance of our skin. People try to find out how to protect the skin from harmful, environmental factors. Every year a lot of new natural and synthetic, chemical substances are discovered. All of them potentially could be used as a cosmetic ingredient. In cosmetology research most of new xenobiotics were tested in vivo on animals. Alternative methods to in vivo tests are in vitro tests with skin cell culture system. The aim of this work was to describe two-dimensional and tree-dimensional skin cell cultures. Additionally, in this work we wanted to prove the usefulness of in vitro skin cell cultures in cosmetology research.

  3. Batch variation between branchial cell cultures: An analysis of variance

    DEFF Research Database (Denmark)

    Hansen, Heinz Johs. Max; Grosell, M.; Kristensen, L.

    2003-01-01

    We present in detail how a statistical analysis of variance (ANOVA) is used to sort out the effect of an unexpected batch-to-batch variation between cell cultures. Two separate cultures of rainbow trout branchial cells were grown on permeable filtersupports ("inserts"). They were supposed...... and introducing the observed difference between batches as one of the factors in an expanded three-dimensional ANOVA, we were able to overcome an otherwisecrucial lack of sufficiently reproducible duplicate values. We could thereby show that the effect of changing the apical medium was much more marked when...... the radioactive lipid precursors were added on the apical, rather than on the basolateral, side. Theinsert cell cultures were obviously polarized. We argue that it is not reasonable to reject troublesome experimental results, when we do not know a priori that something went wrong. The ANOVA is a very useful...

  4. Enhanced light-harvesting capability for silicon single-nanowire solar cells coupled with metallic cavity.

    Science.gov (United States)

    Gai, Feng; Zhang, Cheng; Zhan, Yaohui; Li, Xiaofeng

    2016-12-26

    Single-nanowire solar cells (SNSCs) are attracting increasing interest due to their unique optical antenna effect beneficial for achieving higher light-trapping capability. However, for conventional circular-cross-sectional SNSCs, the light-trapping performance is still far from the expectation. Here we demonstrate that integrating a silicon single nanowire into a metallic slit can dramatically enhance the absorption efficiency over almost the whole spectral band due to strengthened optical antenna effect. Especially, it is found that by using finite-size metallic blocks to form a nanoscale metallic cavity, the light-trapping performance of the SNSCs can be further improved. Through examining the detailed optical spectral response, electric field distribution, and cavity dispersion characteristics, the metallic-coupled SNSC system is optimized and the underlying physics are provided. Simulation results indicate that the photocurrent density of the SNSCs coupled with the designed metallic cavity can be enhanced by 44.4% than that of the conventional bare SNSCs.

  5. Feasibility and Efficiency of Human Bone Marrow Stromal Cell Culture with Allogeneic Platelet Lysate-Supplementation for Cell Therapy against Stroke

    Directory of Open Access Journals (Sweden)

    Chengbo Tan

    2016-01-01

    Full Text Available Currently, there is increasing interest in human bone marrow stromal cells (hBMSCs as regeneration therapy against cerebral stroke. The aim of the present study was to evaluate the feasibility and validity of hBMSC cultures with allogeneic platelet lysates (PLs. Platelet concentrates (PC were harvested from healthy volunteers and made into single donor-derived PL (sPL. The PL mixtures (mPL were made from three different sPL. Some growth factors and platelet cell surface antigens were detected by enzyme-linked immunosorbent assay (ELISA. The hBMSCs cultured with 10% PL were analyzed for their proliferative potential, surface markers, and karyotypes. The cells were incubated with superparamagnetic iron oxide (SPIO agents and injected into a pig brain. MRI and histological analysis were performed. Consequently, nine lots of sPL and three mPL were prepared. ELISA analysis showed that PL contained adequate growth factors and a particle of platelet surface antigens. Cell proliferation capacity of PLs was equivalent to or higher than that of fetal calf serum (FCS. No contradiction in cell surface markers and no chromosomal aberrations were found. The MRI detected the distribution of SPIO-labeled hBMSCs in the pig brain. In summary, the hBMSCs cultured with allogeneic PL are suitable for cell therapy against stroke.

  6. A novel feeder-free culture system for human pluripotent stem cell culture and induced pluripotent stem cell derivation.

    Directory of Open Access Journals (Sweden)

    Sanna Vuoristo

    Full Text Available Correct interactions with extracellular matrix are essential to human pluripotent stem cells (hPSC to maintain their pluripotent self-renewal capacity during in vitro culture. hPSCs secrete laminin 511/521, one of the most important functional basement membrane components, and they can be maintained on human laminin 511 and 521 in defined culture conditions. However, large-scale production of purified or recombinant laminin 511 and 521 is difficult and expensive. Here we have tested whether a commonly available human choriocarcinoma cell line, JAR, which produces high quantities of laminins, supports the growth of undifferentiated hPSCs. We were able to maintain several human pluripotent stem cell lines on decellularized matrix produced by JAR cells using a defined culture medium. The JAR matrix also supported targeted differentiation of the cells into neuronal and hepatic directions. Importantly, we were able to derive new human induced pluripotent stem cell (hiPSC lines on JAR matrix and show that adhesion of the early hiPSC colonies to JAR matrix is more efficient than to matrigel. In summary, JAR matrix provides a cost-effective and easy-to-prepare alternative for human pluripotent stem cell culture and differentiation. In addition, this matrix is ideal for the efficient generation of new hiPSC lines.

  7. Biological Effects of Culture Substrates on Human Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Yohei Hayashi

    2016-01-01

    Full Text Available In recent years, as human pluripotent stem cells (hPSCs have been commonly cultured in feeder-free conditions, a number of cell culture substrates have been applied or developed. However, the functional roles of these substrates in maintaining hPSC self-renewal remain unclear. Here in this review, we summarize the types of these substrates and their effect on maintaining hPSC self-renewal. Endogenous extracellular matrix (ECM protein expression has been shown to be crucial in maintaining hPSC self-renewal. These ECM molecules interact with integrin cell-surface receptors and transmit their cellular signaling. We discuss the possible effect of integrin-mediated signaling pathways on maintaining hPSC self-renewal. Activation of integrin-linked kinase (ILK, which transmits ECM-integrin signaling to AKT (also known as protein kinase B, has been shown to be critical in maintaining hPSC self-renewal. Also, since naïve pluripotency has been widely recognized as an alternative pluripotent state of hPSCs, we discuss the possible effects of culture substrates and integrin signaling on naïve hPSCs based on the studies of mouse embryonic stem cells. Understanding the role of culture substrates in hPSC self-renewal and differentiation enables us to control hPSC behavior precisely and to establish scalable or microfabricated culture technologies for regenerative medicine and drug development.

  8. Aragonite precipitation by "proto-polyps" in coral cell cultures.

    Directory of Open Access Journals (Sweden)

    Tali Mass

    Full Text Available The mechanisms of coral calcification at the molecular, cellular and tissue levels are poorly understood. In this study, we examine calcium carbonate precipitation using novel coral tissue cultures that aggregate to form "proto-polyps". Our goal is to establish an experimental system in which calcification is facilitated at the cellular level, while simultaneously allowing in vitro manipulations of the calcifying fluid. This novel coral culturing technique enables us to study the mechanisms of biomineralization and their implications for geochemical proxies. Viable cell cultures of the hermatypic, zooxanthellate coral, Stylophora pistillata, have been maintained for 6 to 8 weeks. Using an enriched seawater medium with aragonite saturation state similar to open ocean surface waters (Ω(arag~4, the primary cell cultures assemble into "proto-polyps" which form an extracellular organic matrix (ECM and precipitate aragonite crystals. These extracellular aragonite crystals, about 10 µm in length, are formed on the external face of the proto-polyps and are identified by their distinctive elongated crystallography and X-ray diffraction pattern. The precipitation of aragonite is independent of photosynthesis by t