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关键词： 生物反应器   动物细胞   培养  

摘要： 文章结合动物细胞培养的基本特点,介绍了国内外动物细胞培养生物反应器的研究现状以及未来的技术发展方向。

关键词： Enzyme replacement therapy   Lysosomal storage disorders   Parallel bioreactors   Glycan content   Mannose-6-phosphate   beta-Glucuronidase   Chinese hamster ovary cells   Critical quality attributes  

摘要： beta-Glucuronidase is a lysosomal enzyme and a molecular model of a class of therapeutics approved as enzyme replacement therapies for lysosomal storage diseases. Understanding the effect of bioreactor process variables on the production and quality of the biologics is critical for maintaining quality and efficacy of the biotherapeutics. Here, we have investigated the effect of three process variables, in a head-to-head comparison using a parallel bioreactor system (n = 8), namely 0.25 mM butyrate addition, a temperature shift (from 37 to 32 degrees C), and a pH shift (from 7.0 to 6.7) along with a control (pH 7, temperature 37 degrees C, and no additive) on the production and quality of human recombinant beta-glucuronidase (GUS) by a Chinese hamster ovary (CHO) cell line. The study was performed as two independent runs (2 bioreactors per treatment per run;n <= 4). Although statistically not significant, protein production slightly increased with either 0.25 mM butyrate addition (13%) or pH shift (7%), whereas temperature shift decreased production (12%, not significant). Further characterization of the purified GUS samples showed that purification selectively enriched the mannose-6-phosphate (M6P)-containing GUS protein. Noticeably, a variation observed for the critical quality attribute (CQA) of the enzyme, namely M6P content, decreased after purification, across treatment replicates and, more so, across different treatments. The dimer content in the purified samples was comparable (similar to 25%), and no significant discrepancy was observed in terms of GUS charge variants by capillary electrophoresis analysis. MALDI-TOF/TOF analysis of released N-glycans from GUS showed a minor variation in glycoforms among the treatment groups. Temperature shift resulted in a slightly increased sialylated glycan content (21.6%) when compared to control (15.5%). These results suggest that bioreactor processes have a differential effect, and better control is required for achievi

关键词： Bioreactor   Computational fluid dynamics (CFD)   Impeller design   Multi-objective optimization   Particle suspension  

摘要： When agitating mesenchymal stem cells adhered on microcarriers in bioreactors, a compromise has to be found between sufficient particle suspension and limitation of hydromechanical stresses. The present study proposes a strategy to improve the design of an 'elephant ear' impeller at the just-suspended state by varying its relative size, blade slope angle, and position in the reactor. To do that, computational fluid dynamics simulations were coupled with multi-objective optimization to minimize the hydromechanical stress encountered by the microcarriers. Two minimization criteria were considered: (P/V)(@p) and the energy dissipation function EDC. On the basis of 31 conditions, an optimal impeller geometry is proposed.

关键词： Bioreactor   Intermittent agitation   Mixing dynamics   Suspension dynamics  

摘要： Intermittent agitation strategies have been increasingly used for a range of process development applications, i.e., to modulate physical cues, to improve stem cell differentiation yields, and to control hydrodynamic shear stresses in microcarrier suspension;however, there is a distinct lack of characterization. Both continuous and intermittent agitation modes in relation to suspension and mixing dynamics within a DASGIP bioreactor were characterized. Suspension dynamics were found to be affected by microcarrier porosity and the degree of settling was found to be more pronounced at the top of the bioreactor. Mixing time characterization showed a marked improvement in mixing efficiency for intermittent agitation, with an overall dependence on the timing of tracer insertion.

关键词： dip-coating   endothelial cells   fibroblasts   methacryl-modified gelatin   perfusion bioreactor   tubular perfusion system   vascularized tissue engineering  

摘要： Size and function of bioartificial tissue models are still limited due to the lack of blood vessels and dynamic perfusion for nutrient supply. In this study, we evaluated the use of cytocompatible methacryl-modified gelatin for the fabrication of a hydrogel-based tube by dip-coating and subsequent photo-initiated cross-linking. The wall thickness of the tubes and the diameter were tuned by the degree of gelatin methacryl-modification and the number of dipping cycles. The dipping temperature of the gelatin solution was adjusted to achieve low viscous fluids of approximately 0.1 Pa s and was different for gelatin derivatives with different modification degrees. A versatile perfusion bioreactor for the supply of surrounding tissue models was developed, which can be adapted to several geometries and sizes of blood-vessel mimicking tubes. The manufactured bendable gelatin tubes were permeable for water and dissolved substances, like Nile Blue and serum albumin. As a proof of concept, human fibroblasts in a three-dimensional collagen tissue model were successfully supplied with nutrients via the central gelatin tube under dynamic conditions for 2 days. Moreover, the tubes could be used as scaffolds to build-up a functional and viable endothelial layer. Hence, the presented tools can contribute to solving current challenges in tissue engineering.

关键词： Biomass   Nutrient removal   Membrane photobioreactor   Mixed microalgae culture   Polishing  

摘要： Microalgae are used in wastewater treatment successfully by the uptake of nutrients in secondary effluents that can be used as a valuable biomass. In this study, mixed microalgae culture was used for real wastewater treatment plant (WWTP) for polishing the effluent instead of the specific culture, because the specific culture is contaminated under real environmental conditions. Nutrient removal rates, protein and lipid content of the biomass were determined. Volumetric microalgae productivity was found as 0.037 g/L. day with 3 days of sludge retention times (SRT) and 24 h of hydraulic retention time (HRT) in a 5.5 L microalgae submerged membrane photo bioreactor (msMpBR). Total nitrogen (TN) and phosphate phosphorus (PO4-P) removal rates were found to be 5.55 and 0.40 mg/L. day, respectively, while Navicula sp. and Chaetophora sp. cultures were found to be dominant in steady state. The lipid content was 14.33% and raw protein content was 32.69% in dry biomass. The results showed that N and P can be effectively removed from the real wastewaters by mixed microalgae culture and msMpBR and also algal biomass could be produced with good lipid and protein content.

关键词： miniature bioreactor   computational fluid dynamics   mass transfer   shear rate   mixing  

摘要： BACKGROUND Sufficient oxygen supply and stable process control are crucial for the successful screening and process optimization of aerobic microorganisms in small-scale bioreactors. In this work, a miniature bioreactor (volume 80 mL) equipped with non-invasive biosensors was developed and characterized. RESULTS To enable proper mixing and high oxygen transfer rate, a mechanical agitator with large diameter (0.56 tank diameter) and submerged aeration were applied. The flow fields formed in the miniature bioreactor under a wide range of conditions (filling volume 30-70 mL, agitation speed 300-1100 rpm and aeration rate 0-4 vvm) were numerically analyzed by computational fluid dynamics (CFD). The miniature bioreactor performed with a suitable mixing time (<4 s) and a high oxygen transfer coefficient (k(L)a > 1000 h(-1)). It showed that engineering parameters including mass transfer, mixing and shear were more sensitive to agitation than either filling volume or aeration. Correlations for quantitative evaluation of the engineering parameters were established. The predicted oxygen transfer coefficient by CFD showed good agreement with both experimental and reported data. Furthermore, cultivations of Escherichia coli and Pichia pastoris in the mini bioreactor verified the excellent performance. CONCLUSION The developed miniature bioreactor will provide a reliable tool for screening and process optimization, and the presented correlations that predict the engineering parameters will make it convenient to achieve scale-up. (c) 2019 Society of Chemical Industry

关键词： economic model   ex vivo expansion   mesenchymal stromal cells   Vertical-Wheel Bioreactor  

摘要： Mesenchymal stromal cells (MSC) hold great promise for tissue engineering applications and cell-based therapies. Large cell doses (>1 x 10(6) cells kg(-1)) and Good Manufacturing Practices (GMP)-compliant processes are however required for clinical purposes. Here, a serum- and xenogeneic-free (S/XF) microcarrier-based culture system is established for the expansion of human umbilical cord matrix (UCM)- and adipose tissue (AT)-derived MSC using the Vertical-Wheel system (PBS-0.1 MAG;PBS Biotech). UCM and AT MSC are expanded to maximum cell densities of 5.3 +/- 0.4 x 10(5) cell mL(-1) (n = 3) and 3.6 +/- 0.7 x 10(5) cell mL(-1) (n = 3), respectively, after 7 days of culture, while maintaining their identity, according to standard criteria. An economic evaluation of the process transfer from T-flasks to PBS-0.1 MAG shows a reduction in the costs associated with the production of a dose for an average 70 kg adult patient (i.e., 70 million cells). Costs decrease from $17.0 K to $11.1 K for UCM MSC and from $21.5 K to $11.1 K for AT MSC, proving that the transition to Vertical-Wheel reactors provides a cost-effective alternative for MSC expansion. The present work reports the establishment of a scalable and cost-effective culture platform for the manufacturing of UCM and AT MSC in a S/XF microcarrier-based system.

关键词： Municipal solid waste   Bioreactor landfill   Geotextile   Anaerobic biodegradation   Leachate treatment  

摘要： In many developing countries, there has been growing interest in bioreactor landfills for municipal solid waste (MSW) management. This research study has been conducted for comparing leachate characterization and waste stabilization in simulated pilot-scale anaerobic bioreactor landfills. Four pilot-scale reactors were constructed and operated for 540 d. This study aimed to show whether a pilot-scale bioreactor containing sewage sludge mixed with MSW, with a geotextile filter in its drainage layer, and with recirculating leachate, could improve leachate quality and waste stabilization in a landfill. Bioreactor R1 comprised MSW and sewage sludge, while bioreactor R2 was the same as R1 but with a geotextile-1 (GT-1) filter fitted. R3 contained no sludge but only MSW and GT-1 fitted, while R4 contained no sludge but only MSW and two layers of geotextile filter (GT-2 and GT-3). All reactors were operated with leachate recirculation, simulating bioreactor landfills. The results showed that the chemical oxygen demand (COD) half-lives of leachate from the reactors were approximately 8, 7, 9, and 10 months for R1, R2, R3, and R4, respectively. By the end of the study, the waste in R2 and R4 was more stable, with 66% and 65% reductions in volatile solids, respectively. Reactor R2, which contained MSW, sewage sludge, and one-layer geotextile (GT-1), provided higher stabilization of MSW and shorter COD half life than the other reactors.

关键词： Leachate   Biodegradability   Toxicity   Advanced oxidation processes   Galvano-Fenton  

摘要： Mature landfill leachate is among the most difficult effluents to treat because of its complex composition, low biodegradability index and high toxicity. In this study the performances of Galvanic Fenton (GF) and solar Galvanic Fenton (SGF) systems coupled to a biological reactor were evaluated for the remediation of landfill leachate. The SGF and GF systems showed an increase in biodegradability from 0.0022 to 0.1388 and 0.1014, respectively, at 1500 mg hydrogen peroxide (H2O2) L-1 and 30 min of hydraulic retention time (HRT). The GF/biological coupled treatment showed the best performance in chemical oxygen demand (COD) (66.6%), biochemical oxygen demand (BOD) (86.5%), toxicity (90.1%) and organic nitrogen (ON) (93.7%) removal. The GF and SGF effluent characterization by UV-Visible (Uv-Vis), infrared (IR) and fluorescence spectroscopy showed the breaking of aromatic rings and conjugated double bond via the oxidation process. The GF system can be applied to improve the biodegradability index (BI) of leachates and integrated in wastewater treatment prior to a conventional biological treatment.