A new method of 3D printing organs from stem cells
Please type the liver
So, at the beginning of 2012, an 83-year-old Dutch woman was implanted with a titanium jaw printed entirely on a 3D printer instead of a jaw destroyed by cancer. More "Newspaper.En" told about an American girl Emma, the elements of the exoskeleton for which were printed using a printer. This summer, an article appeared in which researchers proposed a liver printing technique that allows cells to grow on a frame of sugar tubes.
Scottish scientists have taken another step towards creating full-fledged organs using 3D printing. They have developed a universal technique for 3D printing tissues using stem cells, which can then be reprogrammed into any necessary cells of organs and tissues. Their work (Alan Faulkner-Jones et al., Development of a valve-based cell printer for the formation of human embryonic stem cell spheroid aggregates, published in the journal Biofabrication, suggests that full-fledged printing of organs and other biological structures will soon become possible.
A 3D bioprinter is a biological variation of reprap technology, a device capable of creating organs and tissues by layering cells on top of each other. The first serial bioprinter was created in December 2009 by the American company Organovo and the Australian company Invetech. Unlike the classical method of growing organs, bioprinting does not require a frame on which cells "sit down", which is an undeniable plus, since the frame can become the initiator of inflammation of the created organ or tissue.
The bioprinter uses two types of "ink" – cells of various types and auxiliary materials (collagen, growth factors, supporting hydrogel), designed to strengthen the created structure until natural connections are formed between the cells.
Previously, for bioprinting, it was first necessary to grow cell cultures from which the organ would be created. The cell culture was cut into small spheroid balls. Spheroids from several separately grown crops were artificially "planted" side by side. The advantage of the new method is that embryonic stem cells (ESCs) capable of developing into any tissue are used for "printing".
One of the authors of the study, Dr. Will Wenmiao Shu from Heriot-Watt University, says: "As far as we know, this is the first case of printing human embryonic stem cells. Generation of 3D structures from ESCs will allow us to create more accurate models of human tissues, which is important in the development of drugs in vitro and the study of their toxicity. Since most drugs are targeted at humans, it makes sense to use human tissue."
In the future, this new method of bioprinting can be used to create artificial organs and tissues ready for transplantation to patients with various diseases.
In the course of the study, scientists from Heriot-Watt University, in collaboration with Roslin Cellab, used a valve printing technique adapted for delicate work with stem cells. The ESCs were loaded into two separate tanks and then applied to the plate according to a pre-prepared scheme. After printing the ESC, a number of tests were carried out in order to understand how effective the new method is. For example, the researchers tested whether the ESCs remained alive after printing and whether they retained the ability to differentiate into different cell types. They also determined the concentration, damage and other characteristics of the "printed" cells to assess the accuracy of the valve method.
"When using the valve method, stem cell printing is regulated by pneumatic pressure and controlled by the opening and closing of the micro valve. The number of cells used can be precisely controlled by changing the nozzle diameter, the air pressure at the inlet or the opening time of the valve," says Dr. Shu.
"We found that the valve printing method is soft enough to maintain high viability of stem cells and accurate enough to produce spheroids of the same size. And most importantly, printed ESCs retain the ability to pluripotency – the ability to differentiate into any other cell types," he noted.
In the field of regenerative medicine, a lot of attention is paid to ESCs. They are obtained from embryos in the early stages of development to produce "stem cell lines" capable of constantly growing and differentiating into any type of human cells. Jason King, Business Development Manager at Roslin Cellab, comments: "This scientific development, we hope and believe, will have important implications for reliable drug testing without the use of animals and, in the long term, for the creation of organs and transplantation "on demand", without the need for donation and without the problems associated with suppression of immunity and possible rejection."
Portal "Eternal youth" http://vechnayamolodost.ru07.02.2013