This paper analyzes the development and application of many types of bioreactors.

Biotechnology Channel News: Traditionally, stem cells such as ESCs and iPSCs have been cultured by wall amplification with serum and feeder layers, i.e. using a standard 2D (two-dimensional) culture model.
such methods need to separate the feeding layer, there is a risk of pathogen contamination, and not easy to operate, cultured stem cells are prone to mutation, cell yield is also limited.
the proposed bioreator solves these problems to some extent.
, many types of bioreators have been developed.
(1) Roller Bottle Bioreactor uses a bottle culturer to grow cells in a constantly shaking cell culture box.
this method is the simplest to operate, the bottle culturer has the characteristics of easy to use, low price and so on.
but this culture system is only suitable for the culture of wall-dependent cells.
monitoring of changes in various chemical and chemical parameters (pH, O2, etc.) in real time, but it is not intuitive enough, and the concentration gradient caused by pH changes still has a great impact on the culture environment.
(2) Stirred suspension culture bioreactor, SSB) This system design is the most classic, the earliest adopted biological reactor, usually composed of tanks, lines, valves, pumps and motors, by the motor-driven blade mixture culture, through the action of agitators so that cells and nutrients in the culture fluid evenly distributed, the tank installed on the different sensors on-line continuous detection of the culture pH, temperature, dissolved oxygen and other parameters.
this method is also relatively simple, suitable for suspended cell culture in the form of cell thymps or single cells, but also suitable for micro-carrier culture of wall cells.
, the changes in various chemical and chemical parameters during SSB culture can be better monitored than in roller bioreactors.
but stirring will cause some damage to cells, more dead cells, there will also be micro-carrier adhesion cells or cell cluster phenomenon occurs.
(3) Wavereactor is a patented product developed in the United States. in the
device, the cells and culture fluid are placed in a pre-venom sterile sterile single-use plastic bag, through the air filtered by the sterilization filter will form a culture container with a certain space, the bag is placed on a rocking platform, with the rocking platform shake left and right, the medium liquid in the bag to form a wave-like movement, play a good mixing effect.
This method through disposable supplies for cell culture, so that the possibility of contamination is minimized, more in line with the requirements of standardized operation, but the operation of cell access and monitoring cell culture status is not simple, at the same time the cost is relatively large.
(4) Rotating wall biological reactor (rotating wall vessel, RWV) system works much the same way as SSB systems and devices, but this method does not use agitation to mix cells and nutrients, but uses rotation to mix.
cells are less damaged and better able to exchange gases than SSB systems.
system requires complex equipment and is not easy to quantify.
(5) Parallel Plate Biorector (PPB) This system typically consists of a multi-layered flat plate, a hollow bracket, and a housing.
the space plate and the plate are fixed on the hollow bracket, which is a hollow cylinder with a diameter of 1 cm, with the upper opening and the lower end closed.
has a fiber stent on each layer of the plate as a carrier for cell attachment.
There are also four long side holes on the upper side of the cylinder, which are divided into layered brackets into a small hole distributed between each of the two layers of brackets, which are used for cell culture and the circulation of culture fluid.
This system can achieve large-scale cell culture, the by-products produced by cell metabolism in the process of its culture can be removed at any time, so that its toxic metabolite content is relatively low, but at the same time the secretion factors produced in cell culture are also reduced, cell culture also has certain harm.
(6) Fixed fluidized bed bioreactors (fixed and fluidized bed bioreactors) provide attachment to cell walls and growth through 3D (three-dimensional) stents, cells are fixed to porous vectors, carriers are fixed in hollow tubes, and mediums flow within tubes.
in a fixed bed, the medium circulates between carriers, in the fluidized bed the carrier flows under the upflow of the medium, and the medium flows between the bed bodies, with the flow, the height of the bed body increases.
that the interaction between cells and cells, cells and substations in this system can better mimic the complex structure of living organisms, and more conducive to cell growth.
but compared to other bioreators, large-scale amplification of cells cannot be carried out.
characteristics of the various biological reactors are described in Table 1.
early bioreathreator studies focused on cell amplification, while in recent years studies have focused on the effects of 3D culture environment on cell surface markers, cell proliferation, differentiation, etc.
the right 3D culture method to create a good environment for cells to maintain the characteristics of stem cells during culture.
conditions, including the establishment of optimal culture environments, the improvement of bioreator structures, and the realization of individual stem cell production processes.
so that various bioreators will have great practical application potential in stem cell in-body culture amplification, directional differentiation and tissue engineering.
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