SEARCH · PubMed Health

Results for “Bioreactors”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

PubMedDate not supplied

Optimal preparation of immobilized liposome-bound cellulase for hydrolysis of insoluble cellulose in an external loop airlift bioreactor.

Immobilized liposome-bound cellulase (ILC) was optimally prepared for the ILC-catalyzed hydrolysis of insoluble cellulose in an external loop airlift bioreactor. The liposomes with mean diameters of 200, 100, and 50 nm were used to prepare three kinds of ILCs, i.e., ILC(200), ILC(100) and ILC(50), respectively. The activity and stability of ILC(100) were examined with soluble cellulose (CMC) in addition to the insoluble substrate of cellulose powder (CC31) in a shaking flask as well as the airlift bioreactors. The experiments were carried out with 45 degrees C and pH 4.8 being found to be optimal for the activity. The activity of ILC(100) was stable in either airlift or shaking flask bioreactor during the five times repeated hydrolyses of CC31 corresponding to a total reaction time of 240 h. This confirmed that the cellulase molecules were covalently bonded to the liposomes covalently bound to the chitosan gel beads. Nevertheless, the activity of ILC(100) with CMC steadily decreased throughout the repeated reactions, suggesting an adverse effect of CMC on the ILC(100) activity. Among the three ILCs, ILC(50) was found to be the most stable and productive biocatalyst during the repeated hydrolyses of insoluble CC31 in the airlift bioreactor. More than 70% of the initial activity of ILC(50) was retained even after the six times repeated reactions for 288 h. Conversely, the ILC(200) was found to be the most unstable catalyst. Such a difference in stability among these ILCs was suggested to be caused by the difference in physical stability of their liposome membranes to the liquid shear stress due to the rising bubbles and circulating liquid as well as that in the amount of the cellulase molecules unstably incorporated in the membranes. ILC(50) was thus shown to have the most potential for an efficient hydrolysis of insoluble cellulose in a practical airlift bioreactor.

Bioreactors↗

PubMedDate not supplied

Scale-up of breast cancer stem cell aggregate cultures to suspension bioreactors.

It has been hypothesized that breast tumor formation results from the activity of a scarce population of cells known as Breast Cancer Stem Cells (BrCSCs) and that the development of effective breast cancer therapies may therefore ultimately rely upon the ability to effectively target these cells for eradication. The scarcity of BrCSCs in vivo severely compromises research on these populations, as analyses are restricted to those requiring small cell numbers, and has become a major impediment to the development of therapeutic strategies against breast cancer. Through the culture of murine tissue aggregates containing a population of BrCSCs, this study demonstrates the ability of propagating this scarce population in a controlled and reproducible manner, within suspension bioreactors. A rigorous theoretical framework has been developed in order to understand and characterize the implications of oxygen mass transfer within aggregates upon scale-up and thereby provide a foundation for the scale-up of aggregate cultures. A two-factor, two-level factorial experimental design was also performed in order to assess the effects of inoculation density and hydrodynamic shear upon cell yield. We discovered that the culture of the murine aggregates in a relatively low shear environment (tau(max) = 0.20 Pa) and inoculated at 3.50 x 10(4) cells/mL resulted in the best yields for the range of conditions investigated in suspension bioreactors. A detailed study on the oxygen uptake kinetics of the aggregates also revealed that the uptake rates were not significantly affected by mass transfer limitations, as uptake rates of aggregate cultures were found to be comparable to those observed in single cell cultures. Cells propagated in a process controlled 500 mL suspension bioreactor resulted in growth kinetics that were comparable to those observed in 125 mL bioreactors. Doubling times in the 500 mL vessel were found to be 23.9 h and attained a maximum cell density of 1.20 x 10(6) cells/mL. After enumerating the number of BrCSCs, this resulted in an approximately 20-fold increase in BrCSC numbers in batch suspension cultures. With greater attention being applied to BrCSCs, their propagation in suspension bioreactors makes available experimental avenues that are not currently accessible and may thereby enable the development of more effective therapeutic drugs for the treatment of breast cancer.

Animals↗

PubMedDate not supplied

Adaptive calibration scheme for quantification of nutrients and byproducts in insect cell bioreactors by near-infrared spectroscopy.

Spectroscopic methods are gaining in popularity in biotechnology because of their ability to deliver rapid, noninvasive measurements of the concentrations of multiple chemical species. Such measurements are particularly necessary for the implementation of control schemes for cell culture bioreactors. One of the major challenges to the development of spectroscopic methods for bioreactor monitoring is the generation of accurate and robust calibration models, particularly because of the inherent variability of biological processes. We have evaluated several methods of building calibration models, including synthetic calibrations and medium spiking methods. The approach that consistently produced reliable models incorporated samples removed from a bioreactor that were subsequently altered so as to increase the sample variation. Several large volume samples were removed from a bioreactor at varying time points and divided into multiple aliquots to which were added random, known amounts of the analytes of interest. Near-infrared spectra of these samples were collected and used to build calibration models. Such models were used to quantify analyte concentrations from independent samples removed from a second bioreactor. Prediction errors for alanine, glucose, glutamine, and leucine were 1.4, 1.0, 1.1, and 0.31 mM, respectively. This adaptive calibration method produces models with less error and less bias than observed with other calibration methods. Somewhat more accurate measurements could be attained with calibrations consisting of a combination of synthetic samples and spiked medium samples, but with an increase in calibration development time.

Alanine↗

PubMedDate not supplied

Hg2+ removal by genetically engineered Escherichia coli in a hollow fiber bioreactor.

Escherichia coli cells engineered to express an Hg2+ transport system and metallothionein accumulated Hg2+ effectively over a concentration range of 0.2-4 mg/L in batch systems. Bioaccumulation was selective against other metal ions and resistant to changes in ambient conditions such as pH, ionic strength, and the presence of common metal chelators or complexing agents (Chen, S.-L.; Wilson, D. B. Appl. Environ. Microbiol. 1997, 63, 2442-2445; Biodegradation 1997, 8, 97-103). Here we report the characterization of the bioaccumulation system based on its kinetics and an isotherm. Bioaccumulation was rapid and followed Michaelis-Menten kinetics. A hollow fiber bioreactor was constructed to retain the genetically engineered cells. The bioreactor was capable of removing and recovering Hg2+ effectively at low concentrations, reducing a 2 mg/L solution to about 5 microgram/L. A mathematical equation that quantitatively described Hg2+ removal by the bioreactor provides a basis for the optimization and extrapolation of the bioreactor. The genetically engineered E. colicells and the bioreactor system have excellent properties for bioremediation of Hg2+-contaminated environments.

Bioreactors↗

PubMed1999

Two-liquid-phase bioreactors for enhanced degradation of hydrophobic/toxic compounds.

Two-liquid-phase culture systems involve the addition of a water-immiscible, biocompatible and non-biodegradable solvent to enhance a biocatalytic process. Two-liquid-phase bioreactors have been used since the mid-seventies for the microbial and enzymatic bioconversion of hydrophobic/toxic substrates into products of commercial interest. The increasing popularity of bioremediation technologies suggests a new area of application for this type of bioreactor. The toxicity and the limited bioavailability of many pollutants are important obstacles that must first be overcome in order to improve biodegradation processes. Two-liquid-phase bioreactors have the potential to resolve both limitations of biotreatment technologies by the enhancement of the mass-transfer rate of compounds with low bioavailability, and by the controlled delivery of apolar toxic compounds. This technology can also be useful in accelerating the enrichment of microorganisms degrading problematic pollutants. In this paper, we discuss the application of two-liquid-phase bioreactors to enhance the biodegradation of toxic/poorly bioavailable contaminants. Important microbial mechanisms involved in this type of system are described. Uptake of the substrates can be achieved by microorganisms freely dispersed in the aqueous phase and/or bound at the interface between the aqueous and the immiscible phases. Production of surface-active compounds and adhesion abilities are microbial features involved in the process. General guidelines for the design of two-liquid-phase bioreactors for biodegradation purposes are presented. Solvent selection should be established on specific criteria, which depend on the characteristics of target compound(s) and the microorganism(s) implicated in the biodegradation process. The central importance of maximizing the interfacial surface area is highlighted. The potential of this approach as an alternative to current biotreatment technologies is also discussed.

Bacteria↗

PubMed1998

Efficacy of a bioreactor filled with porcine hepatocytes immobilized on nonwoven fabric for ex vivo direct hemoperfusion treatment of liver failure in pigs.

We developed a new bioreactor for a bioartificial liver filled with porcine hepatocytes immobilized on polyester nonwoven fabric (NWF) and in our previous study showed that this NWF bioreactor has promising in vitro efficiency. In the present study, we investigated the efficacy of the NWF bioreactor in a direct hemoperfusion experiment conducted to treat pigs with liver failure. Porcine hepatocytes were isolated from the whole liver of a Sangen strain pig. They were immobilized in a 200 ml column containing NWF via perfusion in a closed circuit for 24 h to prepare a NWF bioreactor. The following day an operative liver failure model was produced by creating a portocaval shunt and ligating the entire hepatoduodenal ligament in the porta hepatis. Perfusion treatment was initiated 4 h after operative induction of liver failure and continued for about 1 h. The pigs which underwent perfusion treatment showed significant improvements in survival and blood data, including ammonia, total bile acid, glucose, and prothrombin time, attributed to significant improvements in the post- as compared to the prebioreactor levels in the perfused blood of the treated pigs. These beneficial effects of the NWF bioreactor were based on its excellent composition which allows the accommodation of adequate numbers of hepatocytes and direct contact between hepatocytes and perfused blood.

Ammonia↗

PubMed2001

In vitro and in vivo evaluation of albumin synthesis rate of porcine hepatocytes in a flat-plate bioreactor.

Several configurations of extracorporeal bioartificial liver devices have been developed for the potential treatment of fulminant hepatic failure or as a bridge to liver transplantation. Recently, we developed a microchannel flat-plate bioreactor with an internal membrane oxygenator in which porcine hepatocytes are cultured as a monolayer on the bottom glass surface. In the present study, we investigated synthetic function of porcine hepatocytes in the bioreactor in both in vitro and in vivo flow circuit models. In vitro, albumin synthesis was stable in the bioreactor for up to 4 days of perfusion. In vivo, with the extracorporeal connection of the bioreactor to rat vasculature, porcine albumin was detectable for 24 h in the rat plasma. We also developed a simple mathematical model to predict the in vivo porcine albumin concentration in rat plasma. These results indicate that this configuration of a microchannel flat-plate bioreactor has potential as a liver support device and warrants further investigation.

Albumins↗

PubMed2003

Growth and ginsenoside production in hairy root cultures of Panax ginseng using a novel bioreactor.

We tested the effect of three variables: the bioreactor system (Wave or Spray reactor), medium exchange and culture period, on the capacity of a selected hairy root line of Panax ginseng to produce ginsenosides. Among the reactors, the Wave bioreactor appeared to be the most efficient in promoting hairy root line growth. Periodic exchanges of the medium and a longer culture period increased the growth rate of cultured hairy root line and, consequently, its capacity to produce ginsenosides. Under established optimum conditions (medium exchange every 14 days over a culture period of 56 days using the Wave bioreactor), the initial root fresh weight was enhanced more than 28-fold, giving a root biomass of 284.9 g L(-1) and a ginsenoside content of 145.6 mg L(-1). It is noteworthy that this ginsenoside production exceeded by almost 3-fold that obtained during the shake flask culture of our hairy root line, although it often happens that the scale-up from shake flask to a bioreactor culture results in reduced productivities. To our knowledge this is the first time that a Wave bioreactor has been used for hairy root culture.

Bioreactors↗

PubMedDate not supplied

Recovery of preservation-injured primary human hepatocytes and nonparenchymal cells to tissuelike structures in large-scale bioreactors for liver support: an initial transmission electron microscopy study.

This study investigated large-scale regeneration and tissue reorganization of adult human liver cells from preservation injured transplant organs. The use of basement membrane protein gels and growth factor enriched culture medium in standard culture flasks promotes liver tissue formation in isolated rat and pig hepatocytes, resulting in prolongation of phenotypic stability and metabolic competence of primary cells in vitro. A special bioreactor construction for high-density three-dimensional cell recovery was developed and isolation of cells from discarded human donor livers was enabled. In vitro regeneration of adult human liver cells isolated from preservation-injured organs took place over a period of 2 weeks in a purpose-built bioreactor. Basement membrane protein and growth factors were avoided. Reorganization of tissue structures was studied using transmission electron microscopy (TEM). This showed regeneration and tissue reorganization of adult human cells from preservation-injured organs by coculture with nonparenchymal cells in the bioreactor. The majority of the aggregated hepatocytes in the bioreactors showed morphological similarities to those in vivo (although not re-formed to hepatocyte plates), exhibiting cell-cell junctions and reconstituted bile canaliculi-like spaces between neighboring hepatocytes. Perfusion channels appeared regularly between cell aggregates. The arrangement of nonparenchymal cells between the hepatocyte aggregates exhibited similarities to liver sinusoids. Endothelial cells often covered the aggregates and formed a borderline to the perfusion channels between the capillaries. Similar to the space of Disse, further nonparenchymal cells were located between the endothelial cells and the parenchymal aggregates. Deposits of biomatrix fibers occurred spontaneously. The regenerated cell mass was close to that of a single liver lobe. In conclusion, the further optimization of bioreactors that enable cell recovery from preservation injury may lead to the utilization of cells from discarded whole or split transplants for extracorporeal temporary liver support therapy or hepatocyte transplantation.

Adult↗

PubMedDate not supplied

Effect of low oxygen tension on tissue-engineered cartilage construct development in the concentric cylinder bioreactor.

Cartilage is exposed to low oxygen tension in vivo, suggesting culture in a low-oxygen environment as a strategy to enhance matrix deposition in tissue-engineered cartilage in vitro. To assess the effects of oxygen tension on cartilage matrix accumulation, porous polylactic acid constructs were dynamically seeded in a concentric cylinder bioreactor with bovine chondrocytes and cultured for 3 weeks at either 20 or 5% oxygen tension. Robust chondrocyte proliferation and matrix deposition were achieved. After 22 days in culture, constructs from bioreactors operated at either 20 or 5% oxygen saturation had similar chondrocyte densities and collagen content. During the first 12 days of culture, the matrix glycosaminoglycan (GAG) deposition rate was 19.5 x 10(-9) mg/cell per day at 5% oxygen tension and 65% greater than the matrix GAG deposition rate at 20% oxygen tension. After 22 days of bioreactor culture, constructs at 5% oxygen contained 4.5 +/- 0.3 mg of GAG per construct, nearly double the 2.5 +/- 0.2 mg of GAG per construct at 20% oxygen tension. These data demonstrate that culture in bioreactors at low oxygen tension favors the production and retention of GAG within cartilage matrix without adversely affecting chondrocyte proliferation or collagen deposition. Bioreactor studies such as these can identify conditions that enhance matrix accumulation and construct development for cartilage tissue engineering.

Animals↗

PubMed2006

Effect of seeding and bioreactor culture conditions on the development of human tissue-engineered cartilage.

Human cartilage was produced using fetal chondrocytes seeded into polyglycolic acid (PGA) mesh scaffolds and cultured in recirculation bioreactors. The effect of scaffold thickness, seeding cell density, and bioreactor operating conditions on the quality of the engineered cartilage was investigated. Thin (2.15-mm-thick) PGA scaffolds lost their structural integrity during bioreactor culture and the resulting constructs were small and misshapen compared with tissues generated using 4.75-mm-thick scaffolds. Increasing the seeding cell number from 1.2 x 10(7) to 2.2 x 10(7 )per 4.75-mm-thick scaffold resulted in a doubling of the construct wet weight, a 4.4-fold increase in glycosaminoglycan (GAG) concentration, and a 2.9-fold increase in total collagen concentration in the tissues. Levels of GAG and total collagen were also improved significantly when 100 mL or 50% v/v of the culture medium was replaced periodically during operation of the bioreactors compared with 50, 25, or 5 mL. The proportion of GAG lost from the tissues into the medium was reduced by increasing the seeding cell number and replaced medium volume. This work demonstrates that the quality of tissue-engineered cartilage can be manipulated substantially depending on the cell seeding and bioreactor culture conditions employed.

Bioreactors↗

PubMed2006

Tissue growth in a rotating bioreactor. Part I: mechanical stability.

We develop mathematical models to provide insights into the morphology of a tissue construct formed from a single-cell suspension in culture media, within a rotating bioreactor. The bioreactor consists of a cylindrical vessel of circular cross-section rotating about its longitudinal axis with constant angular speed. Experimental studies show that at rotation rates below a critical value, the cells 'self-assemble' to form smooth 'nodules' that are approximately cylindrical with elliptical cross-section; however, at rotation rates above a critical value, an amorphous construct forms with a highly irregular boundary. The construct is denser than the surrounding culture media and histological studies indicate that the interior of the construct, which is a mix of apoptotic cells and culture media, is surrounded by an outer rim of proliferating cells and collagen. The construct is modelled as a viscous fluid drop surrounded by an extensible membrane in a (less dense) immiscible viscous fluid within a rotating bioreactor. We consider both thin-disk and slender-pipe bioreactors for which the aspect ratio, L(*)/a(*) (where L(*) and a(*) are the bioreactor length and radius, respectively), is small and large, respectively, and obtain a series of spatially 2D problems (independent of the axial coordinate). We then examine the hypothesis that the construct morphology is a result of the mechanical forces that it experiences by considering the interfacial stability of an initially circular fluid-fluid interface to small-amplitude, oscillatory perturbations. The instability is driven by the density difference between the two fluids, and we investigate the effect of the rotation rate, the (time-dependent) gravitational field, and the material and geometrical properties of the system on the stability properties.

Algorithms↗

PubMed2004

In vitro zonation and toxicity in a hepatocyte bioreactor.

The complex architecture of the liver is intertwined with its response to xenobiotic compounds. In particular, hepatocyte subpopulations are distributed along the sinusoid in zones 1 to 3, leading to prototypical "periportal" and "centrilobular" patterns of cell death in response to a toxic insult. In vitro models that more closely represent these zones of sub-specialization may therefore be valuable for the investigation of hepatic physiology and pathophysiology. We have established a perfused hepatocyte bioreactor that imposes physiologic oxygen gradients on co-cultures of rat hepatocytes and non-parenchymal cells, thereby producing an in vitro model of zonation. In order to predict and control oxygen gradients, oxygen transport in a parallel-plate bioreactor containing co-cultures was first mathematically modeled and experimentally validated. Co-cultures exposed to these physiologic oxygen gradients demonstrated regionally heterogeneity of CYP2B and CYP3A protein that mimics the distribution seen in the zonated liver. The distribution of CYP expression in the bioreactor was shown to vary with exposure to different chemical inducers and growth factors, providing a potential platform to study physiologic zonal responses. In order to explore zonal hepatotoxicity, bioreactors were perfused with APAP (acetominophen) for 24 h, resulting in maximal cell death at the low-oxygen outlet region similar to centrilobular necrotic patterns observed in vivo. This hepatocyte bioreactor system enables further in vitro investigation into zonation-dependent phenomena involving drug metabolism and toxicity.

Acetaminophen↗

PubMed1999

Bioreactors for hybrid liver support: historical aspects and novel designs.

A novel bioreactor construction has been designed for the utilization of hepatocytes and sinusoidal endothelial cells. The reactor is based on capillaries for hepatocyte aggregate immobilization. Three separate capillary membrane systems, each permitting a different function are woven in order to create a three dimensional network. Cells are perfused via independent capillary membrane compartments. Decentralized oxygen supply and carbon dioxide removal with low gradients are possible. The use of identical parallel units to supply hepatocytes facilitates scale up. In vitro studies demonstrate long-term external metabolic function in primary isolated hepatocytes within bioreactors. These systems are capable of supporting essential liver functions. Animal experiments have verified the possibility of scaling-up the bioreactors for clinical treatment. However, since there is no reliable animal model for investigation of the treatment of acute liver failure, the promising results obtained from these studies have limited relevance. The small number of clinical studies performed so far is not sufficient to reach conclusions about improvements in the therapy of acute liver failure. Although important progress has been made in the development of these systems, various hepatocyte culture models and bioreactor constructions are being discussed in the literature, which indicates competition in this field of medical research. An overview, which emphasizes the development of hepatocyte culture models for bioreactors, subsequent in vitro studies, animal studies, and clinical application, is also provided.

Animals↗

PubMed2004

Mass transfers in a fluidized bed bioreactor using alginate beads for a future bioartificial liver.

Fluidized bed bioreactor with alginate beads may be an alternative to hollow fiber cartridge to host hepatocytes for bioartificial liver purposes. After the bioreactor design and the characterization of fluid mechanics, the present study was aimed at analyzing bi-directional mass transfers of calibrated species between external fluid and empty beads. Static (batch) and dynamic (fluidized bed bioreactor) experimental conditions were analyzed. A simple modelling approach permitted the definition of mass transfer coefficients. The motion of beads within the bioreactor clearly enhanced mass transfer kinetics, but did not alter the amount exchanged. The shear enhanced diffusion coefficient for VitB12 was 20 times higher in the fluidized bed bioreactor than under batch conditions, proving the efficiency of such a device.

Alginates↗

PubMed2007

Passive treatment of acid mine drainage in bioreactors using sulfate-reducing bacteria: critical review and research needs.

Acid mine drainage (AMD), characterized by low pH and high concentrations of sulfate and heavy metals, is an important and widespread environmental problem related to the mining industry. Sulfate-reducing passive bioreactors have received much attention lately as promising biotechnologies for AMD treatment. They offer advantages such as high metal removal at low pH, stable sludge, very low operation costs, and minimal energy consumption. Sulfide precipitation is the desired mechanism of contaminant removal; however, many mechanisms including adsorption and precipitation of metal carbonates and hydroxides occur in passive bioreactors. The efficiency of sulfate-reducing passive bioreactors is sometimes limited because they rely on the activity of an anaerobic microflora [including sulfate-reducing bacteria (SRB)] which is controlled primarily by the reactive mixture composition. The most important mixture component is the organic carbon source. The performance of field bioreactors can also be limited by AMD load and metal toxicity. Several studies conducted to find the best mixture of natural organic substrates for SRB are reviewed. Moreover, critical parameters for design and long-term operation are discussed. Additional work needs to be done to properly assess the long-term efficiency of reactive mixtures and the metal removal mechanisms. Furthermore, metal speciation and ecotoxicological assessment of treated effluent from on-site passive bioreactors have yet to be performed.

Acids↗

PubMed2004

A novel process for production of hepatitis A virus in Vero cells grown on microcarriers in bioreactor.

AIM: To develop a novel process for production of HAV in Vero cells grown on microcarriers in a bioreactor. METHODS: Vero cells infected with HAV strain W were seeded at an initial density of 1 x 10(5) cells/mL into a 7-L bioreactor containing Cytodex-I microcarriers. During the stage of cell proliferation, the following conditions were applied: pH 7.2 +/- 0.2, temperature 37 +/- 0.2 degrees, dissolved oxygen 40% of air saturation and agitation rate 40 r/min. After the stage of virus culture started, the culture conditions were altered to pH 7.2 +/- 0.2, temperature 35 +/- 0.2 degrees, dissolved oxygen 25% of air saturation, agitation rate 50 r/min and perfusion of fresh medium at a flux of 20 mL/h. During the course of fermentation, cell density, HAV antigen titre, glucose, lactate and ammonia levels were monitored. A control experiment using conventional static culture was conducted in the T150 flask. RESULTS: After a 28-d cultivation, cell density increased to 14.0 x 10(6) cells/mL in the bioreactor, 5.6 x 10(9) viable cells and 4,000 mL virus suspension with a titre of 1:64 were harvested. The viral antigen output per cell unit in the bioreactor was 3-fold higher than that in the T150 flask. Meanwhile the metabolic mode of Vero cells did not change after the infection with HAV strain W. CONCLUSION: The process for production of HAV in Vero cells grown on microcarriers in a bioreactor is a novel, efficient and practical way to obtain virus antigen for vaccine purpose. This approach produces more cells and HAV antigen than the conventional static culture. With further improvement, it is possible to be used for the production of hepatitis A vaccine.

Animals↗

PubMed1999

A simple method for hepatocyte attachment in hollow fibre bioreactors.

A new method for hepatocyte attachment in hollow fibre (HF) bioreactors was proposed and verified. A flow of medium with suspended hepatocytes, evoked by transmembrane pressure (TMP), and directed across the membrane into the fibre lumen, has accelerated and improved hepatocyte contact with the HF. It was found that seeding of hepatocytes onto the membrane was optimal at TMP of 50-80 mmHg. Ammonia utilisation and ureagenesis rates in hepatocytes seeded in the bioreactor suggests that the proposed method warrants proper conditions for cell functionality and allows for extended culture of hepatocytes in HF bioreactors. It is speculated that time cutback between introduction of hepatocytes into the bioreactor and the start of the cell attachment process, accomplished by the presented method, leads to substantially improved recovery of freshly isolated hepatocytes, and consequently to better overall performance of HF bioreactor.

Animals↗