Bioprinters are a special type of 3D printer. Based on computer-controlled tissue engineering, they can produce tissues or bioarrays. In the future, it should be possible to produce organs and artificial living beings with their help.
What is a bioprinter?
Bioprinters are a special type of 3D printer. Bioprinters are technical devices for printing biological tissues and organs in three dimensions by transferring them into living cells. This field of 3D printing is still at an experimental stage and is mainly being investigated in scientific studies in universities. The goal is to create the possibility of producing functional replacement tissues and organs that can be used in medical treatment. The activity word to bioprinter is called bioprinting. Bioprinting starts with the basic composition of the target tissue or organ. The bioprinter is used exclusively in a laboratory environment. The special 3D printer stores and forms thin layers of cells via a print head as a result. To do this, the head of the bioprinter moves left, right, up or down. Bioprinters use bio-ink or bioprocessing protocols to build organic materials. These are biopolymers with cells from living organisms and hydrogels containing up to 90% water. The flow property must be precisely calculated. On the one hand, the mass must be fluid enough so that the needles of the syringes do not clog, and on the other hand, it must be sufficiently solid so that the structure of the target is durable. Other uses for bioprinting include transplantation, surgical therapy, tissue engineering, and reconstructive surgery.
Forms, types, and species
Currently, bioprinters are used very sporadically in the commercial sector. Because bioprinting is in the developmental stage, mature species or types of bioprinters are currently unverified. In principle, however, any 3D printer can be used for bioprinting. To do so, the commonly used PVC powder must be replaced with appropriate cells. Processes are also being tested with which it is possible to develop bioprinters from normal inkjet printers. High demands must be placed on the bio-ink. For example, any substance that is to be used for clinical purposes must meet strict international specifications. Before being used in bioprinting, such substances must undergo years of testing.
Structure and mode of operation
The way a bioprinter works is very similar to the operating principle of an ordinary 3D printer. Molds are built up by means of an extruder. However, no PVC powder is used, as is the case with conventional 3D printers, but a polymer gel, usually based on alginate. Current bioprinters, which are used sporadically in practice, produce droplets each containing between 10,000 and 30,000 individual cells. The organization of these single cells, based on appropriate growth factors, is supposed to come together to form functional tissue structures. Bioprinters require temperature control for accurate printing. Current bioprinters are spatially very large and can be several meters in width, length and height. A computer, usually located outside the printer, controls the syringe plungers. The basis for this is the digitally available data of a 3D model. The bioink is pushed out of the up to eight spray nozzles and the intended structure is built up on a platform.
Medical and health benefits
In principle, bioprinters are expected to be used in three areas in particular in the future: medicine, the food industry and synthetic biology. In medicine, use of bioprinters is conceivable and envisioned in the subfields of surgical therapy, reconstructive surgery, organ donation, and transplantation. Especially in the case of organs by bioprinters, one major advantage is obvious: the exact matching to the body intended for transplantation. In this way, the search for a suitable donor organ that matches the receiving body, which is currently still necessary, can be discontinued. In reconstructive surgery, simplification and improvement are expected.Here, procedures are conceivable in which cells are taken from various parts of the patient’s body – such as ears, fingers and knees. These cells are multiplied in a laboratory. Biopolymer is then added. From such a suspension, the bioprinter can, in theory, build a graft. This is then implanted in the patient. The body’s own cells then degrade the biopolymer over time. The advantage could lie in particular in the fact that the transplant is not rejected by the body. Furthermore, such a transplant could grow with the body. The reason for this positive property is that the implant is linked to the patient’s growth control system. The field of research into the use of bio-implants in medicine continues to grow. At the moment, the production of grafts from cartilage, such as a nose, is very conceivable. More critical is the production of body organs. In particular, the number of capillaries required to supply the organs is currently not conceivable with the necessary precision. Another problem can arise from the fact that in such complex structures as body organs, different cells must be coordinated and communicate with each other in order to perform different functions. Bioprinters can also be used to produce meat in the food industry. The first companies have – according to their own statements – already successfully printed such products. These are said to be both tasty and less costly than slaughtering. However, no meat printed by bioprinting is currently on sale.
