Tissue engineering for the treatment of congenital defects of the diaphragm

An international group of researchers from Sweden, Russia and the USA managed to grow rat diaphragm tissue using their own mesenchymal stem cells and a donor collagen scaffold. When transplanted to animals, this structure acquired all the complex mechanical properties of the muscle tissue of the diaphragm.

The diaphragm is a layer of muscle tissue, continuously contracting and relaxing, which provides respiration of the body. The diaphragm plays an important role in swallowing and it also acts as a barrier between the thoracic and abdominal cavities. Deformities or holes in the diaphragm occur in 1 in 2,500 newborns and can cause severe, often fatal symptoms.

To date, surgical restoration of such defects involves the use of artificial "patches" that do not grow with the child and are not able to contract, which is necessary to maintain breathing. The authors believe that the technology they have developed can be a solution to the problem, as it will allow to grow fragments of muscle tissue from the child's own cells and use them for the full restoration of congenital defects of the diaphragm.

As part of their research, they removed all living cells from the diaphragm tissue of dead donor rats by a series of chemical actions. This process made it possible to get rid of everything that can cause a reaction from the immune system of recipient animals, preserving all connective tissues - the extracellular matrix that provides the structure and mechanical properties of organs. When tested in vitro, the researchers first thought that the resulting tissue scaffolds had lost their critical ability to continuously stretch and contract for extended periods of time. However, after colonization with allogeneic stem cells of the bone marrow and subsequent transplantation to rats, the resulting structures began to function as full-fledged areas of the diaphragm. Three weeks after transplantation of 80% of the right or left dome of the diaphragm, the parameters of myography and spirometry, as well as histological data in experimental rats did not differ from those of healthy animals.

Before conducting clinical trials, the new approach still needs to be tested on larger animal models. However, the developers hope that their proposed method will be at least as effective as the traditional surgical approach to the treatment of congenital defects of the diaphragm with the additional advantage of the ability of the graft to grow with the child.

Article by Gubareva E. et al. Orthotopic transplantation of a tissue engineered diaphragm in rats is published in the journal Biomaterials.

Evgeniya Ryabtseva

Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Karolinska Institutet: New diapragms grown from stem cells offer hope of a cure for common birth defect and possibly future repairs of the heart.