This breakthrough makes it easier to freeze 3D printed tissues that could one day be used for organ transplants.

About 17 people die every day waiting for an organ transplant. One of the ways we can get more organs to patients who need them is by simply creating them from scratch by 3D printing them as live tissue on demand. Scientists have been able to “bioprint” 3D artificial human tissue for clinical research purposes for about two decades now — and over time, we’ve gotten closer and closer to usability of the technology. this to create living organs that can help humans survive.

However, 3D printed organs will face the same big problem as traditional organs – distribution. A new organ from a donor can only last for a few hours because it is transported quickly from one location to another. It must be kept cool, but not too cool, because too low a temperature damages the cells and renders the organ useless. 3D printed tissues have an equally short shelf life.

A group of American scientists think they may have found a solution to this problem. In New findings published in the journal Problem, they report a new way to 3D print and preserve tissues under freezing conditions while preserving them. The team calls their new technique “cryobioprinting”.

Study co-author Y. Shrike Zhang, a biomedical engineer at Harvard University, told The Daily Beast: “It’s always about printing tissues and using them right away. “This limits the ability of these structures to be stored and/or transported between locations. Back in 2017, we started thinking, ‘Can we think of some way we could make it possible to bioprint and store tissues at the same time?’

In traditional 3D printing of tissues, a “biological bond” consists of living cells and mixed with a gelatin-like substance is essentially applied to each surface layer, until you get the structure. the model you are looking for. Cryobioprinting works the same way, except that the biolink is printed on a cold plate, at -20 degrees Celsius.

What’s particularly novel is that the new biolink Zhang and his team developed freezes within milliseconds of being printed, so the 3D tissue structure is built without fear it might lose its shape. This means that very complex and complex tissues can be grown over time – opening the door to bioprinting of entire organs thought to perform a wide range of physiological functions. .

To ensure that these new tissues could safely withstand freezing temperatures, Zhang and his team applied dimethylsulfoxide and various sugars to the bioink. “They have long been used in conventional cryogenic storage of cells and tissues, but their integration into a bio-linked design has not been done before,” said Zhang.

During the study, the researchers demonstrated that tissues can be safely frozen for at least three months before being thawed and resuscitated. The cells in the tissue were shown to function normally and be as healthy as they would be under normal conditions.

This is a very early development in the bioprinting world. Zhang readily admits that much more in-depth research is needed before we’re ready to 3D print a much less frozen, working human organ and resurrect it. At the very least, however, this new breakthrough will make it much easier for clinical scientists to test 3D tissue and find a way to bring us closer to our goal of using 3D-printed organs to one day. save the lives of people in need of organ transplants.