Bioprinter applies a layer of hydrogel (biopaper) in which tissue spheroids (bioink) are accommodated. The procedure is repeated as programmed to form layers, which may differ from each other, until the final layer is printed. This procedure allows creating a construct with a complex structure.
Tissue spheroids -- cell aggregates. Depending on the type of cells, of which it is built, a spheroid will have certain properties. For example, if fabricated of endothelial cells, spheroids with lumens will be formed characteristic of the blood circulatory system. If formed of epithelial cells, spheroids will be without lumens. Bioprinting of a tissue construct is envisioned to involve spheroids of different tissue origin, which allows sophisticated organ constructs to be fabricated.
The main function of biodegradable hydrogels (biopaper) is holding spheroids at certain spacial locations and to serve as a nutritional environment for cells.
Tissue spheroids (bioink) is the key element of the 3D bioprinting process. Tissue spheroids are building blocks used for the fabrication of 3D tissues and organs. Tissue spheroids have a lot of remarkable properties, the most important one for bioprinting being their intrinsic ability of self-aggregation or self-assembly in the process of tissue concrescence governed by the surface tension force. In other words, tissue spheroids can launch tissue concrescence process. The natural phenomenon of tissue spheroid fusion provides a foundation for robotic biofabrication of organ and tissue constructs with a bioprinter.
Unique software
The software used for controlling bioprinting process allows using different number of nozzles and in different configurations.
The bioprinter was designed taking into account all known limitations of existing bioprinting technologies and currently is the best universal and multifunctional bioprinter in the world.
In 2015, 3ders.org http://www.3ders.org/articles/20151109-3ders-monday-warm-up-the-top-20-3d-bioprinters.html put FABION on the list of world’s top 20 bioprinters.
FABION has a total of 5 nozzles with programmable capacity for dispensing bioink and biopaper. Three nozzles are for dispensing bioink. Spheroids of any type or size as well as various cells suspensions or other materials can be loaded into each of these three nozzles. For each nozzle it is possible to set the number of tissue spheroids to be dispensed, thickness of printed layer as well as other process parameters. The other two nozzles are of a different design as they are for biopaper. Biopaper can be applied by pulverisation or dispensing.
The software developed for the bioprinter is compatible with various 3D modelling programs and support different file formats of polygonal modelling. To launch the process of bioprinting certain parameters need to be fed into the control software, the main ones being the following:
- Distance between the centers of the spheroids; positioning of spheroids in the coordinate grid; distances between the positions of the nozzles along X, Y and Z axes; nozzle movement sequence (motion of each nozzle loaded with certain material must be set for each cell in the coordinate grid).
- Speed.
- Volumes of biopaper and bioink to be dispensed, all necessary parameters for the bioprinter’s X-Y-Z positioning system. In addition, it is possible to enter a broad range of input data, such as, for example, time and intensity of the UV radiation source.
