Abstract: A kit and method for evaluating in vitro the effect of a xenobiotic (e.g., a biologic drug) on drug metabolism in hepatocytes. The kit comprises a first culture of hepatocytes, a portion of in vitro xenobiotic-stimulated biological sample, and instructions for incubating the first culture of hepatocytes with the portion of in vitro xenobiotic-stimulated biological sample, and analyzing the activity, expression, or a combination thereof of a biomarker in the hepatocytes to evaluate the effect of the xenobiotic on drug metabolism in the hepatocytes.

Abstract: A microfluidic device for evaluating a tissue sample can include a tissue chamber, a liquid inlet channel, a liquid outlet channel, and at least one of components (1)-(3). The tissue chamber can be defined by a plurality of walls, at least one of which is transparent. The liquid inlet and outlet channels can be in fluid communication with the tissue chamber. Components (1)-(3) can include: (1) a deformable membrane disposed within the tissue chamber and being configured to oscillate, upon application of pressure thereto, to mechanically compress the tissue sample; (2) first and second electrodes disposed about the tissue chamber and being configured such that delivery of electrical energy thereto creates an electrical gradient across the tissue chamber; and (3) at least one deformable wall, which partially defines the tissue chamber and is configured to stretch either uniaxially or biaxially upon application of negative pressure to the tissue chamber.

Abstract: Embodiments described herein generally relate to methods and systems for using an air removal chamber as a control for a process in a cell expansion system. The air removal chamber may be mounted on a fluid conveyance assembly for use with the system. Fluid is pumped into a fluid containment chamber of the air removal chamber, in which the level of fluid in the fluid containment chamber may be monitored through the use of one or more sensors. The sensors are capable of detecting air, a lack of fluid, fluid, and/or a gas/fluid interface, e.g., an air/fluid interface, at measuring positions within the air removal chamber. Protocols for use with the system may include one or more stop conditions. In an embodiment, the stopping of a process is automated based on the detection of air, a lack of fluid, and/or a gas/fluid interface in the air removal chamber.

Abstract: Provided herein are microfluidic devices that can be used as a 3D bioassay, e.g., for drug screening, personalized medicine, tissue engineering, wound healing, and other applications. The device has a series of channels {e.g., small fluid channels) in a small polymer block wherein one or more of the channels can be filled with a biologically relevant gel, such as collagen, which is held in place by posts. As shown herein, when the device is plated with cells such as endothelial cells, new blood vessels grow in the gel, which is thick enough for the cells to grow in three dimensions. Other channels, e.g., fluid channels, allow drugs or biological material to be exposed to the 3D cell growth. Cells, such as endothelial cells, can be cultured and observed as they grow on the surface of a 3D gel scaffold, where e.g., rates of angiogenesis can be measured, as well as intervascularization and extravascularization of cancerous cells.

Abstract: The systems and methods disclosed herein are generally related to a cell culture system. More particularly, the systems and methods enable the culturing and interconnecting of a plurality of tissue types in a biomimetic environment. By culturing organ specific tissue types within a biomimetic environment and interconnecting each of the organ systems in a physiologically meaningful way, experiments can be conducted on in vitro cells that substantially mimic the responses of in vivo cell populations. In some implementations, the organ systems are fluidically connected with a constant-volume pump.

Abstract: A method of making a structure having a patterned a base layer and useful in the fabrication of optical and electronic devices including bioelectronic devices includes, in one embodiment, the steps of: a) providing a layer of a radiation-sensitive resin; b) exposing the layer of radiation-sensitive resin to patterned radiation to form a base layer precursor having a first pattern of exposed radiation-sensitive resin and a second pattern of unexposed radiation-sensitive resin; c) providing a layer of fluoropolymer in a third pattern over the base layer precursor to form a first intermediate structure; d) treating the first intermediate structure to form a second intermediate structure; and e) selectively removing either the first or second pattern of resin by contacting the second intermediate structure with a resin developing agent, thereby forming the patterned base layer.

Abstract: A nucleic acid extraction device includes: a tube section in which are disposed in this order a first plug formed of oil, a second plug formed of a washing liquid immiscible with oil and for washing a substance adsorbing a nucleic acid, a third plug formed of oil, a fourth plug formed of an elution liquid immiscible with oil and for eluting the nucleic acid from the substance, and a fifth plug formed of oil; and a cover section disposed around the tube section.

Abstract: Devices, systems, and methods for continuous cell culture and other reactions are generally described. In some embodiments, chambers (e.g., cell growth chambers) including at least a portion of a wall formed of a flexible member are provided. A retaining structure can be incorporated outside and proximate to the chamber such that when liquid is added to the chamber, the flexible member is consistently and predictably deformed, and a consistent volume of liquid is added. The flexible member can be formed of, in some embodiments, a gas-permeable medium. In some embodiments, reaction chambers can be arranged in a fluidic loop, and a bypass channel can be used to introduce and/or extract fluid from the loop without affecting loop operation.

Abstract: A nucleic acid extraction device has: a tube extending in a longitudinal direction in which a first plug formed of a wax or an oil, a second plug formed of a first washing liquid, a third plug formed of a wax, a fourth plug formed of an eluate, and a fifth plug formed of a wax or an oil are arranged in this order.

Abstract: A microfluidic device for controlled encapsulation of particles of sub-millimetric dimensions, or clusters of such particles, the device comprising: a first duct for delivering a first liquid phase containing particles for encapsulating in suspension; a second duct for conveying a flow of a second liquid phase that is immiscible with said first liquid phase; the first duct opening out into the second duct and forming a fluidic junction therewith; at least one microfluidic duct for discharging the first liquid phase flowing in said first duct and provided with a mouth located upstream from said junction and liable to be obstructed, at least in part, by a particle in suspension, thereby causing pressure to rise in the first duct. The invention also provides a microfluidic system including such a device, and a method of encapsulation based on using such a device.

Abstract: A system for harvesting totipotent plant tissue culture can include a sterile enclosure, a plurality of bioreactors in the sterile enclosure, at least one agitator in the sterile enclosure, and a culture harvest system. The at least one agitator can be configured to agitate culture within the plurality of bioreactors. The culture harvest system can include tubing configured to connect to a port of one of the plurality of bioreactors in the sterile enclosure, a culture harvest container, and a pump configured to pump culture from the one of the plurality of bioreactors into the culture harvest container via the tubing.

Abstract: A system for culturing photosynthesizing microorganisms includes a source of a gaseous fluid a mixer that creates micron bubbles within an aqueous medium using the gaseous fluid. The mixing chamber holds the aqueous medium including the micron bubbles before the micron bubbles and aqueous medium are mixed with a culture of photosynthesizing microorganism in a reaction chamber.

Abstract: A cartridge for nucleic acid amplification reaction includes a tube including, on the inside, in order, a first plug formed by first oil, a second plug formed by a cleaning solution, which causes phase separation when mixed with oil, a third plug formed by second oil, a fourth plug formed by an eluate, which causes phase separation when mixed with oil, and a fifth plug formed by the third oil, a container for nucleic acid amplification reaction communicating with the fifth plug side of the tube and including fourth oil, and a plunger attached to an opening section on the first plug side of the tube and configured to push out liquid from the fifth plug side of the tube to the container for nucleic acid amplification reaction. All of the first to third oils have specific gravities different from the specific gravity of the fourth oil.

Abstract: A reactor system is provided for improved fermentation of a gaseous substrate through the introduction of a secondary loop to a forced-circulation loop reactor. The reactor comprises a primary loop through which fermentation broth comprising a gaseous substrate is circulated through a riser segment and a downcomer section by a loop pump. Downstream of the loop pump a portion of fermentation broth is withdrawn from the downcomer section and is directed to the top of the reactor via a secondary loop. Further provided is a method for improving the mass transfer of a gaseous substrate to a fermentation broth in a fermentation vessel comprising a secondary loop. Further provided is a method for reducing foam in the headspace of a fermentation vessel comprising a secondary loop.

Abstract: Disclosed is a cell culture tube, having in opposite end walls two respective eccentric openings which communicate with each other through an inner straight passage formed in the cell culture tube, in which the inner straight passage is tilted at an angle relative to a longitudinal axis of the cell culture tube to allow a culture medium to smoothly flow into and out of the inner passage through the openings. Also, provided is a multiple cell culture system using a plurality of the culture tubes.

Abstract: The present invention provides a liquid reflux reaction control device comprising: a reaction vessel having one or a plurality of wells configured to accommodate a sample; a heat exchange vessel provided in contact with the reaction vessel so as to conduct heat to the reaction vessel, and comprising an inlet and an outlet respectively for introducing and draining a liquid of a predetermined temperature; a plurality of liquid reservoir tanks provided with a temperature-controllable heat source for maintaining liquids of predetermined temperatures; a tubular flow channel that connects the inlet and the outlet of the heat exchange vessel with the liquid reservoir tanks; a pump disposed on the tubular flow channel, and configured to circulate the liquid between the heat exchange vessel and the liquid reservoir tank; and a switching valve disposed on the tubular flow channel, and configured to control the flow of the circulating liquid, which controls the temperature of the reaction vessel to keep a desired tem

Abstract: A perifusion device includes at least one sample container for cells, the sample container having an inlet and an outlet. The container receives test liquid through the inlet and discharges the liquid through the outlet. A manifold having a plurality of liquid inlets, control valves, and liquid outlets can be provided. A receptacle housing has a plurality of receptacles. A drive is connected to the receptacle housing for moving the receptacle housing. A programmable controller can be provided to control movement of the receptacle housing. The test liquid includes at least one stimuli for the cells. The liquid collected in the receptacles is analyzed to determine the response of the cells to the stimuli.

Abstract: An assembly capable of capturing and purifying expressed biological products during or at the end of a bioreaction cycle is disclosed wherein a binding resin is kept separated from the contents of the bioreactor allowing capturing, harvesting and purification of biological products in a bioreactor; the invention additionally provides means of removing undesirable metabolic products as well as provides for efficient loading of chromatography columns.

Abstract: In one embodiment, a bioreactor includes a cartridge adapted to deliver growth media to inner and outer surfaces of a tubular organ scaffold, the cartridge having a container that includes a first passage adapted to deliver a first growth medium to the inner surfaces of the tubular organ scaffold and a second passage adapted to deliver a second growth medium to the outer surfaces of the scaffold, wherein the first and second growth media are different media.

Abstract: Methods, systems, and compositions for growing high density cultures of dechlorinating microorganisms, such as the bacteria Dehalococcoides. Dechlorinating cultures are grown in continuous flow stirred-tank reactors at short hydraulic retention time, resulting in improved batch production. For some cultures, a culture medium including chlorine containing compounds, bicarbonate, and HEPES utilized.

Abstract: A cartridge for nucleic acid amplification reaction includes a tube that has a first plug, a second plug formed of a second washing solution washes nucleic acid-binding solid-phase carriers having bound to a nucleic acid, a third plug, a fourth plug formed of a reverse transcription reaction solution which undergoes phase separation when being mixed with oil and in which a reverse transcription reaction occurs, a fifth plug formed of a third oil, a sixth plug formed of an eluate which causes the nucleic acid to be eluted from the nucleic acid-binding solid-phase carriers having bound to the nucleic acid, and a seventh plug in this order in the inside of the tube; a container for nucleic acid amplification reaction that is in communication with the tube and contains oil; and a plunger that pushes liquid to the container for nucleic acid amplification reaction out of the tube.

Abstract: Flow chambers are provided. In some embodiments, the flow chambers include an inner panel having at least one flow channel having an inlet/outlet opening on each end thereof formed therein, wherein the inlet/outlet openings are adapted to releasably receive a septum; one or more ports adapted to releasably receive a plug and for at least liquid communication with the at least one flow channel, and an outer frame that defines an outer portion of the at least one flow channel and that defines a perimeter of the flow chamber. In some embodiments, the flow chamber has overall dimensions of a standard multiwell plate and the at least one flow channel is located in a position that corresponds to a column location of the standard multiwell plate. Also provided are methods for producing the presently disclosed flow chambers and employing the same to assay biological features of cultured cells and/or tissues.

Abstract: A method and system are provided for supporting the growth of algae cells. Initially, an inoculum of algae cells are grown in a closed bioreactor. Thereafter, the inoculum is passed into an open Expanding Plug Flow Reactor (EPFR). Growth medium is added at a plurality of locations along the EPFR. This addition is controlled in response to the growth rate of the algae cells to maintain a substantially same concentration of cells at each location in the EPFR. At all times, the medium provides sufficient nutrients to support growth and maintain a high concentration of algae cells, i.e., at least 0.5 grams per liter of medium, in the EPFR. After the desired level of growth is reached, the algae cells are transferred from the EPFR to a standard plug flow reactor wherein oil production is activated in the algae cells.

Abstract: The present invention is generally related to systems and methods to permit the growth of anaerobic, ethanol-producing bacteria using pretreated biomass such as cellulose in a manner to facilitate the efficient conversion of cellulose to ethanol.

Abstract: Cell expansion systems and methods of use are provided. The cell expansion systems generally include a hollow fiber cell growth chamber, and first and second circulation loops (intracapillary loops and extracapillary loops) associated with the interior of the hollow fibers and exterior of the hollow fibers, respectively. Detachable flow circuits and methods of expanding cells are also provided.

Abstract: A perifusion device includes at least one sample container for cells, the sample container having an inlet and an outlet. The container receives test liquid through the inlet and discharges the liquid through the outlet. A receptacle housing has a plurality of receptacles for receiving fluid from the outlet of the sample container. A drive is connected to the receptacle housing for moving the receptacle housing such that liquid samples are collected sequentially from the outlet of the sample containers. A computer can be provided to control movement of the receptacle housing at predetermined times, and to record data identifying liquid samples in the receptacles. The test liquid includes at least one stimuli for the cells, which can be the presence, absence, or concentration of a compound in the liquid, or a physical property of the liquid such as temperature. The liquid collected in the receptacles is analyzed to determine the response of the cells to the stimuli.

Abstract: Disclosed is a microfluidic chip and method using the same. The microfluidic chip comprises a substrate having a surface, and at least a tissue culture area formed on the surface of the substrate. The tissue culture area has a microfluidic channel formed by a plurality of connected geometrical structures (nozzle-type channels) having a predetermined depth. The microfluidic channel has an inlet and an outlet, which are at two ends of the microfluidic channel, for medium inputting and outputting, respectively. Additionally, at least an air-exchange hole is formed on the bottom of the microfluidic channel. By using the microfluidic chip for tissue culture, lateral flow speed and stress can be decreased, so as to prolong survival time of tissues (e.g. liver tissues).

Abstract: The system for fermentation using algae of the present invention includes a first reactor and a second reactor being in fluid communication with each other. A first valve placed between the first reactor and the second reactor controls the fluid connection between the reactors. A gas inlet, in fluid connection to the first reactor, is located at an end opposite the second reactor. A devolatization unit or cell lysis chamber is connected to the second reactor by a second valve. A biomass stream having gas, liquid and biosolids contents passes through the first reactor with gas. The biomass stream mixes and dissolves the gas in the reactors. The cellular structure of the biomass stream ruptures in the devolatization unit, allowing the processed materials, such as oil, gas, and biosolids, to be harvested for use.

Abstract: A system (10) for forming and maintaining a biological tissue by which a biological tissue can be artificially formed by culturing cells, which comprises a pulse pump (12), a circulation pathway (13) having such a circuit structure as allowing a liquid cell culture medium discharged from the pulse pump (12) to return into the pulse pump (12), and a cell culture section (14A) and a gas exchange section (14B) provided along the circulation pathway (13). The cell culture section (14A) holds a cell holder (H) in such a manner to form a first channel wherein the liquid cell culture medium flowing in the circulation pathway (13) passes through the cell holder (H) and returns into the circulation pathway (13) and a second channel wherein the liquid cell culture medium flowing in the circulation pathway (13) passes outside the cell holder (H) and returns into the circulation pathway thereby bringing about a difference in pressure between the liquid cell culture medium passing through the respective channels.

Abstract: Embodiments of the invention provide a bioreactor chamber assembly comprising: a bioreactor chamber comprising first and second portions arranged to be coupled to one another thereby to provide a liquid-tight seal therebetween; a pair of clamp members; and a pair of resilient loop elements, wherein the clamp members are arranged to sandwich the chamber between the clamp members and the loop elements are arranged to apply a force between the clamp members to urge the first and second portions together.

Abstract: A photobioreactor assembly, including a first generally horizontal manifold, a second generally horizontal manifold positioned below the first generally horizontal manifold, an array of generally parallel, generally transparent tubes extending between the manifolds, an air supply operationally connected to at least one manifold, a water filter, a water purifier, a water supply operationally connected to the water purifier, a pH sensor positioned to measure the pH in the array, and an electronic controller operationally connected to the pH sensor, the air supply, the water purifier, and the water supply. Each respective tube is connected in fluidic communication with the first horizontal manifold, and each respective tube is connected in fluidic communication with the second horizontal manifold.

Abstract: A nucleic acid extraction device includes a tube that is internally provided with, in the following order, a first plug composed of a first oil, a second plug composed of a first washing liquid, which is phase-separated from an oil and is used for washing a nucleic acid-binding solid-phase carrier having nucleic acids bound thereto, a third plug composed of a second oil, a fourth plug composed of a reverse transcription reaction solution, which is phase-separated from an oil and is used for performing a reverse transcription reaction, a fifth plug composed of a third oil, a sixth plug composed of an eluent, which is phase-separated from an oil and is used for eluting the nucleic acids from the nucleic acid-binding solid-phase carrier having nucleic acids bound thereto, and a seventh plug composed of a fourth oil.

Abstract: A microfluidic device is provided for analyzing or sorting biological materials, such as polynucleotides, polypeptides, proteins, enzymes, viruses and cells. The invention can be used for high throughput or combinatorial screening. The device comprises a main channel and an inlet channel that communicate at a droplet extrusion region so that droplets of solution are deposited into an immiscible solvent in the main channel. Droplets can thereafter be sorted according to biological material detected in each droplet.

Abstract: A microfluidic device is provided for analyzing or sorting biological materials, such as polynucleotides, polypeptides, proteins, enzymes, viruses and cells. The invention can be used for high throughput or combinatorial screening. The device comprises a main channel and an inlet channel that communicate at a droplet extrusion region so that droplets of solution are deposited into an immiscible solvent in the main channel. Droplets can thereafter be sorted according to biological material detected in each droplet.

Abstract: One or more embodiments are described directed to a method and system for concentrating components of a fluid circulated through a cell growth chamber such as a cell growth chamber. Accordingly, embodiments include methods and systems that utilize a tangential flow filter to concentrate components of a fluid that in embodiments includes expanded cells. In embodiments, a concentrated fluid component and a concentrated cell component are generated by flowing the fluid with expanded cells across a tangential flow filter. The concentrated cell component may be recirculated to the tangential flow filter to reach some desired concentration of cells. The concentrated fluid component may be collected to utilize cellular-produced constituents in the concentrated fluid component.

Abstract: Methods and devices for amplifying nucleic acids generally involve exposing the nucleic acid to an electromagnetic field, for example a mini-current magnetic field, while performing the steps of PCR. The PCR methods and devices provide numerous advantages over conventional PCR techniques and systems such as reduced reaction times, no heating requirements, and reduced amounts of reagents (e.g., optional use polymerases and primers). Additionally, the PCR methods and devices require significantly shorter reaction times (e.g., less than one hour) compared to conventional PCR techniques and systems (minimum 2 hours). Finally, as shown in the Examples, the PCR methods and devices amplify significantly more DNA compared to conventional PCR techniques and systems. Accordingly, the PCR methods and devices provide a more efficient and cost-effective way to perform PCR when compared to conventional PCR techniques and systems.

Abstract: An inflatable bioreactor bag for cell cultivation, which comprising a top and a bottom sheet of flexible material, joined together to form two end edges and two side edges, wherein one baffle or a plurality of baffles extend from the bottom sheet in a region where the shortest distance to any one of the two end edges is higher than about one fourth of the shortest distance between the two end edges.

Abstract: The present invention provides an apparatus and a method for producing lactic acid, wherein only lactic acid is selectively absorbed and separated from fermentation liquor using a lactic acid absorption resin and wherein a neutralizing agent is not used. The present invention does not include a neutralizing process and a process of converting lactate to lactic acid. The method of the present invention comprises the steps of: adding and mixing a culture medium, microorganism and sugar in a fermenter; passing a fermentation liquor through a microorganism filtration unit to remove microorganism through a cross-flow filtration; and selectively absorbing and separating lactic acid from filtered liquid using a lactic acid absorption resin. Accordingly, the separation and purification process of lactic acid from a fermentation liquor for polymerization is simplified. The manufacturing cost is thus reduced.

Abstract: The invention relates to a method of cultivation of algae or cyanobacteria in the presence of a luminous material that converts light of a first wavelength to a second wavelength more suitable for use in photosynthesis by the algae or cyanobacteria, and apparatus for performing the method. In one embodiment the apparatus (50) is of flexible plastic with fluorescent light concentrator or light guide (76) and perforated pipe (56) for bubbling carbon dioxide through the culture. The algae or cyanobacteria may be used to produce biofuels.

Abstract: The invention is a reverse-flow method and system for the loading, proliferation and differentiation of cells into and throughout an implantable biocompatible three-dimensional scaffold.

Abstract: A method for forming peristaltic pump cassettes includes cutting tubing segments to different lengths based on the physical properties of the individual tubing segments. The size variations compensate for the physical parameters of the tube and improve accuracy in a peristaltic pump using the cassettes.

Abstract: Developing heart valves are exposed to dynamic strains by applying a dynamic pressure difference over the leaflets. The flow is kept to a minimum, serving only as a perfusion system, supplying the developing tissue with fresh nutrients. Standard heart valves were engineered based on B trileaflet scaffolds seeded with cells isolated from the human saphenous vein. Tissue compaction is constrained by the stent, inducing increasing pre-strain in the tissue. The dynamic strains the tissues are exposed to via the dynamic pressure difference, are estimated using finite element methods based on the mechanical properties of the neo-tissue, in order to get inside into the strain distribution over the leaflet.

Abstract: Disclosed herein is a diffusion-limiting reactor having a first element and a closure element, said reactor having at least two interconnected reservoirs said interconnection being by non-impinging microchannel, and at least one said reservoir and said microchannel being magnetic accessible. Further disclosed is a method of sample separation.

Abstract: The invention provides systems, devices, and methods for heating and cooling chemical or biological samples, such as genetic materials during Polymerase Chain Reaction (“PCR”). The systems, devices, and methods comprise use of a fluid that performs repeated heating and cooling cycles, e.g., ‘thermal cycling’, on sample reactants with a phase changing fluid during evaporation and condensation. The systems, devices, and methods eliminate the need for a heating block as a means to obtain fast and uniform thermal cycling. The disclosure also describes the use of an optical system in conjunction with the thermodynamic cycler for real-time detection. Ultimately, uniformity and speed of the thermodynamic cycler provides for higher sensitivity and throughput of gene replication and detection.

Abstract: A device 1 with at least one electrode 8 for generating an electrical field in a chamber 7 is disclosed. The device 1 comprises at least one input channel 6 for introducing a fluid into the chamber 7, and at least one output channel 11 for discharging the fluid from the chamber 7. Also disclosed is a method for stabilizing the flow of a fluid through a chamber 7 in which an electrical field is generated and which has at least one input channel 6 for introducing the fluid into the chamber and at least one output channel 11 for discharging the fluid from the chamber 8. To avoid undesirable backflow of the fluid due to gas formation, the average inside diameter of the input channel 6 of device 1 is smaller than the average inside diameter of the output channel 11.

Abstract: Cell expansion systems and methods of use are provided. The cell expansion systems generally include a hollow fiber cell growth chamber, and first and second circulation loops (intracapillary loops and extracapillary loops) associated with the interior of the hollow fibers and exterior of the hollow fibers, respectively. Detachable flow circuits and methods of expanding cells are also provided.

Abstract: The present invention relates to a unit (1) comprising a microsystem (150) and at least one set of interface connections (16) for the microsystem (150); the microsystem (150) comprising a bottom plate (152) bearing the impression of at least one microstructured dynamic cell culture chamber (15), and a top plate (151), characterized in that the at least one microstructured chamber (15) is fluidically connected at inlet and/or at outlet by a set of connections (16) inserted removably into a hole in the upper plate (151). The present invention also relates to a dynamic cell culture system to this effect.

Abstract: Systems and methods are provided for controlling the diameter of a mammalian hybrid coronary bypass graft. The system includes a controller having at least one input for receiving information and feedback information and an output for outputting control signals, including at least one steady flow system control signal; and a pressure/flow loop subsystem coupled to the controller. The pressure/flow loop subsystem includes a specimen holder, an external flow loop system coupled to the specimen holder, a steady flow system, and an output for outputting the feedback information. The pressure/flow loop subsystem receives the control signals and is capable of adjusting a diameter of a specimen in accordance with the control signals, when the specimen holder contains the specimen.

Abstract: Developing heart valves are exposed to dynamic strains by applying a dynamic pressure difference over the leaflets. The flow is kept to a minimum, serving only as a perfusion system, supplying the developing tissue with fresh nutrients. Standard heart valves were engineered based on B trileaflet scaffolds seeded with cells isolated from the human saphenous vein. Tissue compaction is constrained by the stent, inducing increasing pre-strain in the tissue. The dynamic strains the tissues are exposed to via the dynamic pressure difference, are estimated using finite element methods based on the mechanical properties of the neo-tissue, in order to get inside into the strain distribution over the leaflet.

Abstract: The method and apparatus according to the present invention concentrate the formation of the biotechnical product to active site in the reactor, where the production is accelerated to extreme speeds by altering the conditions. To achieve this, anabolic, catabolic or overflow metabolic reactions can be utilised. The aim is to implement production so that carbon dioxide emissions in particular are minimised The products are e.g. 2,3-butanediol, butanol, ethanol, acetone, organic acids, methane or hydrogen gas and other fuels or compounds necessary for chemical or material production.