Ink on the wound
A group of Canadian researchers led by Professor Axel Gunter from the University of Toronto has successfully tested a new portable three-dimensional bioprinter for the treatment of deep burns on pigs, which allows printing new tissues directly onto the wound.
The new system will provide patients with extensive burn injuries with artificial skin to close defects in the near future.
Currently, skin grafts in place of the removed damaged tissue are taken from another area of the patient's body. However, in cases where there are extensive deep burns, there is not always enough healthy skin to use. There are alternative sources of skin, including scaffolds using cow collagen or artificial skin substitutes grown in vitro, but none of them is ideal. Collagen scaffolds need the tissues and cells surrounding the wound to begin the healing process, while growing artificial skin in vitro can take a long time. In addition, there are difficulties with the successful transplantation of her patient with extensive burns.
The research team has developed a portable device for applying skin precursor layers directly to wounds of any size, shape and topography. For printing, biochernils based on fibrin – a protein involved in blood clotting – are used with mesenchymal stromal cells that support cell growth and help restrain the body's immune system.
On the left: an illustration of the use of a portable bioprinter. On the right: the scheme of delivery of bio-ink from the printer directly to the wound surface. Source: IOP Publishing.
As a rule, the wound surface is not perfectly smooth and is not always oriented horizontally. Therefore, one of the most important advantages of a bioprinter is that it is able to evenly apply layers of ink on uneven surfaces.
The new device was tested for the treatment of deep burns in pigs. It was found that the layers of skin precursors were applied to the wound evenly, safely and reliably, and they remained in place with minimal displacement.
The presence of mesenchymal stromal cells in the ink contributed to more effective healing by reducing the processes of inflammation, scarring and tightening, compared with both untreated wounds and wounds on which a collagen framework was applied.
The authors write that the internal device of the printer offers a convenient way to safely deliver any cells and biomaterials, and the potential clinical application of the device goes far beyond the treatment of burn injuries.
Article by R.Y.Cheng et al. Handheld instrument for wound-conformal delivery of skin precursor sheets improves healing in full-thickness burns is published in the journal Biofabrication.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of IOP Publishing: New handheld bioprinter holds promise for treating serious burns.