Objectives: Multiple types of bioreactors with perfusate are used for the culturing and examination of cell cultures and their interaction with the perfusion media. In case of use with full blood or ...corpuscular blood components as perfusion medium, the traumatization of the necessary pump is a crucial aspect The usual roller pumps create unacceptable trauma and activation, due to the low priming volume and the multiple exposition of the blood particles to the pump shear. Methods: Multiple types of bioreactors with perfusate are used for the culturing and examination of cell cultures and their interaction with the perfusion media. In case of use with full blood or corpuscular blood components as perfusion medium, the traumatization of the necessary pump is a crucial aspect. The usual roller pumps create unacceptable trauma and activation, due to the low priming volume and the multiple exposition of the blood particles to the pump shear. Results: First tests showed a hemolysis increase for the MP of only 1.4 compared to 25.3 mg/dL/hour for the RR.ICAM-1, HLA-DR and CD11 b were moderately activated by MP, but massively by RP. In contrast to RP, MP did not cause the expression of procoagulatory tissue factor on monocyte surface. Conclusions: A minipump with very cheap disposable components could be developed, which caused very low blood trauma In first tests.
Objectives: The synergistic effects of convection and a distributed and delocalized nutrient transport in hollow fibre membrane bioreactors(HFMBs) have been recently reported to benefit the culture ...of cm-scale BMSC aggregates, possibly by relieving nutrients limitations typical of other bioreactors for bone tissue engineering (BTE). Mathematical modelling of mass transport, cells growth and metabolic reactions is particularly interesting given the difficulty to monitor non-invasively solutes concentration in the presence of a closed shell, to optimize bioreactor design and operation. Most proposed models consider cells uniformly distributed in the extracapillary space, in contrast with experimental results under high convective flows, and are then inadequate for this purpose. This paper presents mathematical models of nutrients profiles inside HFMBs operated in close shell mode from diffusion-limited to convection-dominant mass transport conditions for both uniform cell distribution and the actual non-uniform cell distribution observed in experiments with BMSCs. Methods: Models are based on a multi-compartment description of HFMBs based on the Krogh cylinder assumption, and on a quasi-steady state analysis of nutrients evolution and cell concentration profiles. Relevant non-dimensional parameters were identified, and governing momentum and mass transport equations were numerically solved with a finite element commercial code. Metabolic parameters for primary and immortalized cell were used, proliferation and distribution parameters were assessed from culture experiments. Results: The use of low metabolic requirement cell types, like immortalized ones makes the design of bioreactors for 3D constructs culture easier, being diffusion-limited nutrients transport models inadequate only for cell density close to natural bone tissue. Simulation results demonstrate the importance of convective nutrient transport, membrane permeability and packing density in the cell compartment on nutrients concentration in the ECS when primary cells are used. Conclusions: Convection-dominant nutrients transport is necessary to overcome nutrient transport limitation when culturing cells types with physiological metabolic requirements in 3D cm-scale constructs.
Objectives: In cardiac regenerative medicine, hydrogel-based injectable scaffolds (hydrogel) are becoming a promising strategy for supporting the regeneration of injured heart. The rationale for this ...study is to assist the design of an innovative low-cost perfusion bioreactor for cell-seeded hydrogel feasibility testing, in which microgravity condition is realized by establishing a mixing slow vortex that allows adequate cell-seeded hydrogel suspension and oxygen transport without using rotating components. Computational fluid dynamics was applied to assist the bioreactor design and to identify the operating conditions that optimize mass transport in the culture chamber. Methods: The finite volume method was applied to simulate 3D multiphase (culture medium, cells, oxygen) fluid-dynamics, integrating calculations of diffusion, convection and consumption for assessing 1) the optimal geometric design, 2) the proper flow regime to be established within the culture chamber, and 3) the oxygen distribution and its consumption by cells. Results: Remarkable differences in the cell-seeded hydrogel distribution and suspension, in the shear stress distributions, and in the oxygen distribution and consumption arise due to variations in perfusion parameters. Our main findings are the optimization of the geometry of the chamber and the identification of a range of flow rate values that 1) allow cell-seeded hydrogel suspensions, avoiding sedimentation at the bottom of the chamber, 2) guarantee a safe range of shear stress values on cells, and 3) permit appropriate oxygenation. Conclusions: The present study allowed to properly design an innovative low-cost perfusion bioreactor (without rotating components) for cell-seeded hydrogel culture in microgravity conditions, ensuring homogenous distribution of cell-seeded hydrogel and adequate oxygen cellular consumption, and avoiding shear-induced cell damage. Findings from computational simulations will serve as criteria to set the operating conditions for future in vitro tests. The present work is carried out in the scope of BIOSCENT Project (ID 214539).
The physiological mechanisms how stem cells are led into a threedimensional regenerative process are presented as the basis of a bionic concept of stem cell therapy. This platform technology uses the ...wound as a triggering cofactor for in situ and in vivo technology as an alternative to in vitro stem cell theories and methods. The preparatory process is made possible by tissue specific bioreactors and highly standardized processes. In a diabetic wound the capacity of regeneration is significantly reduced or totally lost. We have developed a technology that topically activates this regeneration potential by endogenous stem cell activation and combines it with an ad hoc transplant of cells obtained from the peripheral blood of the patient. This approach intends to mimic the normal wound healing process while the homologous application of blood cells allows paracrlne effects of the transplant that improve healing. The scientific rationale and technology focuses on an in situ & In vivo rather than a conventional In vitro use and induces an in situ boosting and commitment effect for stem cells that leads to an improved tissue regeneration. The elucidation of the underlying mechanisms, the positive regulatory environment and the safety of the process, the striking preclinical and pilot clinical results do warrant a further development in multicentre clinical trials. Tissue regeneration in skin (burns, diabetic wounds) and bone defects has become a clinical reality. Apart from these areas other tissue applications including cartilage, liver, spinal cord injury, heart valves or trachea are being developed as well. Stem cells are the basis for regeneration and bioreactors are the instruments that make the respective biological technologies available for clinical therapy. Apart from mechanistic studies, preclinical animal trials and early clinical examples are presented.
The implementation of bioreactor systems for the production of bacterial inoculants as biofertilizers has become very important in recent decades. However, it is essential to know the bacterial ...growth optimal conditions to optimize the production and efficiency of bioinoculants. The aim of this work was to identify the best nutriment and mixing conditions to improve the specific cell growth rates (µ) of two PGPB (plant growth-promoting bacteria) rhizobial strains at the bioreactor level. For this purpose, the strains Sinorhizobium mexicanum ITTG-R7sup.T and Sinorhizobium chiapanecum ITTG-S70sup.T were previously reactivated in a PY-Casup.2+ (peptone casein, yeast extract, and calcium) culture medium. Afterward, a master cell bank (MCB) was made in order to maintain the viability and quality of the strains. The kinetic characterization of each bacterial strain was carried out in s shaken flask. Then, the effect of the carbon and nitrogen sources and mechanical agitation was evaluated through a factorial design and response surface methodology (RSM) for cell growth optimization, where µ was considered a response variable. The efficiency of biomass production was determined in a homemade bioreactor, taking into account the optimal conditions obtained during the experiment conducted at the shaken flask stage. In order to evaluate the biological quality of the product obtained in the bioreactor, the bacterial strains were inoculated in common bean (Phaseolus vulgaris var. Jamapa) plants under bioclimatic chamber conditions. The maximum cell growth rate in both PGPB strains was obtained using a Y-Casup.2+ (yeast extract and calcium) medium and stirred at 200 and 300 rpm. Under these growth conditions, the Sinorhizobium strains exhibited a high nitrogen-fixing capacity, which had a significant (p < 0.05) impact on the growth of the test plants. The bioreactor system was found to be an efficient alternative for the large-scale production of PGPB rhizobial bacteria, which are intended for use as biofertilizers in agriculture.
SARS-CoV-2 was identified as the pathogenic agent causing the COVID-19 pandemic. Among the proteins codified by this virus, the Spike protein is one of the most-external and -exposed. A fragment of ...the Spike protein, named the receptor binding domain (RBD), interacts with the ACE2 receptors of human cells, allowing the entrance of the viruses. RBD has been proposed as an interesting protein for the development of diagnosis tools, treatment, and prevention of the disease. In this work, a method for recombinant RBD production using Pichia pastoris as a cell factory in a stirred-tank bioreactor (SRTB) up to 7 L was developed. Using a basal saline medium with glycerol, methanol, and compressed air in a four-stage procedure, around 500 mg/L of the raw RBD produced by yeasts (yRBD) and 206 mg/L of purified (>95%) RBD were obtained. Thereby, the proposed method represents a feasible, simple, scalable, and inexpensive procedure for the obtention of RBD for diagnosis kits and vaccines’ formulation.
The complex space environments can influence cell structure and function. The research results on space biology have shown that the major mutagenic factors in space are microgravity and ionizing ...radiation. In addition, possible synergistic effects of radiation and microgravity on human cells are not well understood. In this study, human immortal lymphoblastoid cells were established from human peripheral blood lymphocytes and the cells were treated with low dose (0.1, 0.15 and 0.2 Gy) cumulative super(60)Co gamma -irradiation and simulated weightlessness obtained by culturing cells in the Rotating Cell Culture System (RCCS). The commonly used indexes of cell damage such as micronucleus rate, cell cycle and mitotic index were studied. Previous work has proved that Gadd45 (growth arrest and DNA-damage-inducible protein 45) gene increases with a dose-effect relationship, and will possibly be a new biological dosimeter to show irradiation damage. So Gadd45 expression is also detected in this study. The micronucleus rate and the expression of Gadd45 alpha gene increased with irradiation dose and were much higher after incubation in the rotating bioreactor than that in the static irradiation group, while the cell proliferation after incubation in the rotating bioreactor decreased at the same time. These results indicate synergetic effects of simulated weightlessness and low dose irradiation in human cells. The cell damage inflicted by gamma -irradiation increased under simulated weightlessness. Our results suggest that during medium- and long-term flight, the human body can be damaged by cumulative low dose radiation, and the damage will even be increased by microgravity in space.
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•The predominate phyla were Firmicutes (0.40–0.08) and Actinobacteria (0.03–0.08).•The abundant Olsenella and Clostridium were the superior genera.•Volatile fatty acids composition ...and the bacterial community had a strong correlation.•A higher organic loading rate affected the bacterial community specialization.
This study was designed to evaluate the microbial profiling of anaerobic digestion during the processing of sewage sludge and food waste to volatile fatty acids (VFAs) in an immersed membrane bioreactor (iMBR) operating with a distinct organic loading rate (OLR). The results indicated that Firmicutes (0.17–0.38) and Actinobacteria (0.20–0.32) phyla dominated in anaerobic digestion with OLRs of 4 and 8 g VS/L/d, while Firmicutes (0.04–0.08), Actinobacteria (0.03–0.08) and Proteobacteria (0.02) were more abundant with OLR of 6 and 10 g VS/L/d in the bioreactors. Subsequently, the abundance of the Clostridium and Lactobacillus genera were responsible for higher yields of acetate, butyrate, caproate and lactate. The species of Clostridium sp. W14A (0.04–0.06), Bacterium OL-1(0.01–0.30) and Lactobacillus mucosae (0.002–0.01) were rich for both OLR dosages. Additionally, network and redundancy analysis confirmed that Clostridium sp. W14A, Bacterium MS4 and Lactobacillus had significant correlations with the VFAs produced, such as acetate, butyrate, and caproate. Variation analysis also demonstrated an appreciable correlation between environmental factors and the bacterial community. Overall, this bacterial community was dominated by the Firmicutes (0.04–0.38) phylum and Clostridium sp. W14A (0.04–0.60) species, which is a clear indicator of a lower population of acetogenic bacteria associated with greater VFAs generation.
Hispidin (6-(3,4-dihydroxystyrl)-4-hydroxy-2-pyrone) production in submerged cultured mycelia of the basidiomycete Inonotus hispidus was doubled in shake flasks through irradiation with white light. ...The daily addition of 1 mM hydrogen peroxide as a chemical stressor and a repeated supplementation of the shake flask cultures with 2 mM caffeic acid, a biogenetic precursor, further increased the hispidin synthesis. These cultivation conditions were combined and applied to parallel fermentation trials on the 4 L scale using a classical stirred tank bioreactor and a wave bag bioreactor. No significant differences in biomass yield and colorant production were observed. The hispidin concentration in both bioreactors reached 5.5 g·Lsup.− sup.1 , the highest ever published. Textile dyeing with hispidin was successful, but impeded by its limited light stability in comparison to industrial dyes. However, following the idea of sustainability and the flawless toxicity profile, applications in natural cosmetics, other daily implements, or even therapeutics appear promising.
