2D stacking takes the ability to print living organs one step closer

In an effort to make the production of biomaterials more accessible, researchers at the University of California, Berkeley are combining 2D bioprinting, a 3D assembly robotic arm, and flash freezing in a method that could one day allow living tissues and even whole organs to be printed. By printing organs as thin sheets of tissue, then freezing them and stacking them one after the other, the new technology improves the survival of biocells both during printing and further storage.

Biomaterials have great potential for the medicine of the future. 3D printing with the patient's own stem cells will help create transplantable organs that are fully compatible and will not cause rejection.

The problem is that current bioprinting methods are slow and don't scale well, because it's hard for cells to survive the printing process without very tight temperature and chemical control. Also additional complexity is imposed by further storage and transportation of printed fabrics.

To overcome these problems, the Berkeley team decided to parallelize the printing process and divide it into successive steps. That is, instead of printing the entire organ in one go, tissues are simultaneously printed in two-dimensional layers, which are then stacked by a robotic arm to create the final three-dimensional structure.

This approach already speeds up the process, but to reduce cell death, the layers are immediately immersed in a cryogenic bath to freeze them. According to the team, this greatly optimizes the conditions for the survival of printed materials during storage and transportation.

“Currently, bioprinting is mainly used to create a small amount of tissue,” says Boris Rubinsky, professor of mechanical engineering. “The problem with 3D bioprinting is that it's a very slow process, so you won't be able to print anything big because the biological materials will be dead by the time you're done. One of our innovations is that we freeze tissues as they are printed, so that the biological material is preserved.”

The team acknowledges that this layered approach to 3D printing is not new, but its application to biomaterials is an innovation. This allows layers to be printed in one location and then transported to another for assembly.

In addition to creating tissues and organs, this technique has other applications, such as the production of frozen food on an industrial scale.

The study was published in Journal of Medical Devices.

Source: 3dnews.ru