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The technology of operative 3D-printing of cartilage from stem cells has been created
Anatoly Glossev, Vesti
Scientists have developed a technology for creating artificial cartilage tissue using stem cells and a 3D printer. Printing can be done right during surgery, "repairing" damaged joints.
The achievement is reported by a scientific article published in the journal Biofabrication by a group led by Claudia Di Bella from the University of Melbourne (Onofrillo et al., Biofabrication of human articular cartilage: a path towards the development of a clinical treatment).
Hyaline cartilage tissue is a tough nut to crack for tissue engineering. It contains relatively few cells, but it is rich in intercellular collagen fibers organized into special three-dimensional structures and containing complex proteins proteoglycans.
Scientists have been trying to create an artificial replacement for it for a long time to help patients with injuries, osteoarthritis and other damage to cartilage tissue. However, while such technologies are far from perfect.
According to the Physics World resource, so far the replacement of damaged cartilage tissue occurs in two stages. First, the patient has his own cartilage removed. Then its artificial analogue of the desired shape is created. After that, a repeat operation is required to insert the implant.
At the same time, failures often occur. This is partly due to the imperfection of artificial cartilage, which is not always able to function for a long time in the body. Another reason is that it is difficult to make a "patch" that is ideally suited in shape to a specific affected area.
The new technology solves both problems at once. Firstly, artificial fabric is used, more similar to natural. Secondly, the structure of the implant is corrected in real time right during the operation. A portable 3D printer is used for this.
As the edition of Medicalexpress clarifies, printing takes place by extrusion. The patient's stem cells are embedded in "ink" from gelatin methacrylate and hyaluronic acid methacrylate (both materials have long been used in medicine). After the gel takes a form that is ideal for correcting a specific defect, it is irradiated with ultraviolet light. As a result, chemical reactions begin, during which the material acquires the mechanical properties of natural cartilage.
This technology has already been tested on sheep. In addition, the researchers tested the quality of the resulting tissue in the laboratory.
To do this, they took mesenchymal stem cells from the subcutaneous tissue of donors. Stem cells of this type can turn into "bricks" of bone, cartilage, muscle or adipose tissue (note that sometimes such diversity negatively affects the results, and scientists have to look for more highly specialized candidates). They added these cells to the "ink" along with chemical stimulants that encourage them to become cartilage cells. After that, the researchers printed artificial tissue and grew it "in vitro" for eight weeks.
After this period, the samples were subjected to the most thorough analysis. They were studied using optical and atomic force microscopes, interaction with electromagnetic radiation was checked, gene expression was analyzed, immunohistological methods were tested, mechanical properties were found out, and so on. All tests showed excellent compliance with natural human cartilage tissue.
In the future, the researchers plan to conduct more experiments with animals before it will be possible to proceed to the phase of clinical trials of the technology on humans.
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