-196 ℃ + 3D printing, new technology makes biological tissue storage more convenient
According to the latest paper in the journal matter, researchers at Brighen and Women's Hospital and Harvard Medical School in the United States have combined 3D biological printing with cryopreservation technology to create tissue that can be stored in a freezer at minus 196 ℃ and can be thawed for immediate use in a few minutes.
A major obstacle to the extensive research and clinical application of 3D printing biological tissues is that their shelf life is very short, which may range from a few hours to a few days.
Just like an organ transplant, biological tissue must be transported quickly to where it is needed, or it cannot survive.
The use of 3D bio-printing technology to make artificial human tissue first appeared 20 years ago. Unlike traditional 3D printing, in biological printing, ink usually consists of gelatin scaffolds embedded in living cells. The working principle of frozen biological printing is the same, except that the printing is carried out directly on a cold plate with a temperature as low as minus 20 ℃. After the tissues are printed out, they are immediately moved to low temperatures for long-term storage.
Cryogenic printing has the added advantage that it can produce more complex shapes than traditional biological printing methods. "the biological ink thread freezes within milliseconds after it reaches the cold plate and will not deform." "then we can create a separate 3D structure layer by layer," said lead author Y Shrek Zhang, a biomedical engineer at Brigan and Women's Hospital. "
The use of low temperatures also removes restrictions on the types of printing ink that can be used. In traditional biological printing methods, ink must be viscous to maintain its shape, but at lower temperatures, most liquids naturally become thicker.
Cryopreservation is a necessity for cells to survive at low temperatures. It prevents osmotic shock and limits the formation of ice crystals that may damage cell membranes. This time, the researchers focused more on finding cryopreservation agents that can maximize cell vitality.
They proved that biological tissue can be preserved for at least three months before it comes back to life again. "reviving biological tissue is like reviving any type of cryopreserved cells, that is, putting them back into a warm medium and thawing them quickly," Zhang said. "
In order to prove that these tissues can retain their original functions, the researchers conducted a series of cell activity analyses to prove that cells can undergo the same process of differentiation as before.
In the future, 3D biological tissue printing may become a realistic model for testing new drugs or helping patients with disease and injury who need to replace tissue. Tissue that can freeze bio-printing for a long time will enable researchers to further collaborate in the development of these applications and have the opportunity to extend their storage time for use in preclinical and clinical environments.
At present, based on the previous development of allogeneic tissue engineering repair materials with good biocompatibility, Shandong Yinfeng Institute of Life Sciences has developed a 3D biological printing roadmap and is committed to a new type of biological printing "ink". The use of 3D biological printing technology to achieve rapid, fine and customized molding of biological scaffolds. Provide more accurate personalized repair materials for tissue loss and injury caused by surgery, various diseases and accidents. It has a good application prospect as a biological scaffold in the filling and regeneration of diabetic foot and all kinds of soft tissue.