			Home About us Contact

Scale Bioreactor (scale + bioreactor)

Distribution by Scientific Domains

Life Sciences	100%

Selected Abstracts

Differentiation and lineage selection of mouse embryonic stem cells in a stirred bench scale bioreactor with automated process control

BIOTECHNOLOGY & BIOENGINEERING, Issue 7 2005
Magnus Schroeder
Abstract It is well established that embryonic stem (ES) cells can differentiate into functional cardiomyocytes in vitro. ES-derived cardiomyocytes could be used for pharmaceutical and therapeutic applications, provided that they can be generated in sufficient quantity and with sufficient purity. To enable large-scale culture of ES-derived cells, we have developed a robust and scalable bioprocess that allows direct embryoid body (EB) formation in a fully controlled, stirred 2 L bioreactor following inoculation with a single cell suspension of mouse ES cells. Utilizing a pitched-blade-turbine, parameters for optimal cell expansion as well as efficient ES cell differentiation were established. Optimization of stirring conditions resulted in the generation of high-density suspension cultures containing 12.5,×,106 cells/mL after 9 days of differentiation. Approximately 30%,40% of the EBs formed in this process vigorously contracted, indicating robust cardiomyogenic induction. An ES cell clone carrying a recombinant DNA molecule comprised of the cardiomyocyte-restricted alpha myosin heavy chain (,MHC) promoter and a neomycin resistance gene was used to establish the utility of this bioprocess to efficiently generate ES-derived cardiomyocytes. The genetically engineered ES cells were cultured directly in the stirred bioreactor for 9 days, followed by antibiotic treatment for another 9 days. The protocol resulted in the generation of essentially pure cardiomyocyte cultures, with a total yield of 1.28,×,109 cells in a single 2 L bioreactor run. This study thus provides an important step towards the large-scale generation of ES-derived cells for therapeutic and industrial applications. © 2005 Wiley Periodicals, Inc. [source]

Heterologous Expression of Vitreoscilla Hemoglobin (VHb) and Cultivation Conditions Affect the Alkaloid Profile of Hyoscyamus muticus Hairy Roots

BIOTECHNOLOGY PROGRESS, Issue 2 2006
Annika Wilhelmson
Fast-growing hairy root cultures of Hyoscyamus muticus induced by Agrobacterium rhizogenes offer a potential production system for tropane alkaloids. Oxygen deficiency has been shown to limit growth and biomass accumulation of hairy roots, whereas little experimental data is available on the effect of oxygen on alkaloid production. We have investigated the effect of Vitreoscilla hemoglobin (VHb) expression and cultivation conditions on the complete alkaloid profile of H. muticus hairy roots in shake flasks and in a laboratory scale bioreactor. We optimized the growth medium composition and studied the effects of sucrose, ammonium, nitrate, and phosphate on growth and alkaloid production. Maximum biomass accumulation was achieved with the highest and maximum hyoscyamine content with the lowest sucrose concentration. The optimum nitrate concentration for growth was higher for the VHb line than the control. Neither VHb expression nor aeration improved the hyoscyamine content significantly, thus suggesting that hyoscyamine biosynthesis is not limited by oxygen availability. Interestingly, the effect of VHb expression on the alkaloid profile was slightly different from that of aeration. VHb expression did not affect the concentrations of cuscohygrine, which was increased by aeration. Therefore, the effect of VHb is probably not related only to its ability to increase the intracellular effective oxygen concentration. [source]

Rapid monitoring of recombinant antibody production by mammalian cell cultures using fourier transform infrared spectroscopy and chemometrics

BIOTECHNOLOGY & BIOENGINEERING, Issue 3 2010
Christopher A. Sellick
Abstract Fourier transform infrared (FT-IR) spectroscopy combined with multivariate statistical analyses was investigated as a physicochemical tool for monitoring secreted recombinant antibody production in cultures of Chinese hamster ovary (CHO) and murine myeloma non-secreting 0 (NS0) cell lines. Medium samples were taken during culture of CHO and NS0 cells lines, which included both antibody-producing and non-producing cell lines, and analyzed by FT-IR spectroscopy. Principal components analysis (PCA) alone, and combined with discriminant function analysis (PC-DFA), were applied to normalized FT-IR spectroscopy datasets and showed a linear trend with respect to recombinant protein production. Loadings plots of the most significant spectral components showed a decrease in the C,O stretch from polysaccharides and an increase in the amide I band during culture, respectively, indicating a decrease in sugar concentration and an increase in protein concentration in the medium. Partial least squares regression (PLSR) analysis was used to predict antibody titers, and these regression models were able to predict antibody titers accurately with low error when compared to ELISA data. PLSR was also able to predict glucose and lactate amounts in the medium samples accurately. This work demonstrates that FT-IR spectroscopy has great potential as a tool for monitoring cell cultures for recombinant protein production and offers a starting point for the application of spectroscopic techniques for the on-line measurement of antibody production in industrial scale bioreactors. Biotechnol. Bioeng. 2010; 106: 432,442. © 2010 Wiley Periodicals, Inc. [source]

Optimization of cultivation conditions in spin tubes for Chinese hamster ovary cells producing erythropoietin and the comparison of glycosylation patterns in different cultivation vessels

BIOTECHNOLOGY PROGRESS, Issue 3 2010
Jure Strnad
Abstract This article describes the optimization of cultivation factor settings, that is the shaking rate and working volume in 50 mL spin tubes for a Chinese hamster ovary cell line expressing recombinant human ,-erythropoietin, using a response D-optimal surface method. The main objectives of the research were, firstly, to determine a setting in which the product titer and product quality attributes in spin tubes are equivalent to those in 250 mL shake flasks in a seven day batch and, secondly, to find a setting in which the product titer is maximal. The model for product titer prediction as a function of shaking rate and working volume in the defined design space was successfully applied to the optimization of cultivation conditions in spin tubes for the tested cell line. Subsequently, validation experiments were carried out simultaneously in spin tubes, shake flasks and bench scale bioreactors to compare cell culture performance parameters such as growth, productivity and product quality attributes in the form of isoform profiles and glycan antennarity structures. The results of the experiments showed that similar cell culture performance and product quality could be achieved in spin tubes when compared to shake flasks. Additionally, bioreactor titers could be reproduced in spin tubes at high shaking rates and low working volumes, but with differing product quality. Cultivation at lower shaking rates in spin tubes and shake flasks produced a glycoprotein with a product quality slightly comparable to that from bioreactors, but with titers being only two thirds. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source]