Hot printing
Researchers at the University of Washington in Seattle and Rice University in Houston are working together to improve the bioprinting of organ-like liver and lung tissues. These artificial tissues can be used, for example, to study how drugs or toxins act on the liver. The ultimate goal of the researchers is to create artificial tissues that could take over the lost functions of a diseased organ, in particular, the liver, and which could be surgically implanted in patients.
The liver has a complex structure and performs hundreds of functions. Its cells receive instructions from genes, which, through the expression of proteins, direct them to designated places to perform certain actions.
The mechanisms of gene regulation and information transfer to cells are becoming increasingly clear. However, it was not possible to launch these paths at the request of the researchers.
A new study has developed a thermofluid bioprinting technology that creates tissues that mimic the signaling pathways found in the human liver.
Researchers have developed a liquid system with three-dimensional printing to supply penetrating heat. The energy of this system allows manipulating the genetic structure of cells deep inside artificial tissues. To do this, thermal templates are used to trigger gene expression. The heat from the printed matrix activates the genes of the living cells placed in it, which are induced by an increase in temperature.
A convoluted hydrogel channel filled with thermofluid fluoresces under ultraviolet light (left), and infrared tomography of a heat-perfused hydrogel shows that heat is radiated along the fluid flow and dissipated in a volumetric hydrogel. Drawings from an article in Science Advances.
These manipulations can show how the formation of a genetic pattern within different cells affects the separation of tissues according to the functions performed. In the future, the approach can be used to create organs from stem cells, as well as to remotely control implanted tissues and achieve the desired therapeutic effect.
The heat exchange technology for Activation of transcription (Heat Exchangers for Activation of Transcription, HEAT) in the experiment activated the Wnt signaling pathway, which, as the researchers explain, is important for regulating development, homeostasis and tissue regeneration throughout the animal kingdom.
Thus, HEAT is an independent way of controlling gene expression. The elegance of the technology lies in the fact that it uses mass transfer with a flow of thermal energy, and both of these phenomena obey similar laws of physical exchange.
Infrared tomography of a hydrogel perfused with a cubic thermofluid channel.
Researchers write about the disadvantages of HEAT, in particular, the inability to fully control the time and place of heat supply. But they believe that design modifications will help overcome some of the existing limitations. This approach can also be combined with other advances in tissue engineering, together they will provide new opportunities for the bio-production of three-dimensional tissues and organs.
Article by D.C.Corbett et al. Thermofluidic heat exchangers for actuation of transcription in artificial tissues is published in the journal Science Advances.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of UW Medicine: The heat is on for building 3D artificial organ tissues.