Stretching for growing artificial cartilage
Grown in the conditions of tension cartilage (top) has properties similar to the properties of natural cartilage. On the lower image shows a computer simulation of the stress distribution in an artificial tissue.
Researchers at the University of California, Davis, working under the guidance of Professor Kyriakos Atanasiu (Kyriacos Athanasiou), grown in the laboratory, bioengineered tissue, mechanical and biochemical properties similar to cartilage tissue of the person. The peculiarity of the developed methods was the fact that the fabric was cultivated under the conditions of tension, but the supporting frame.
Articular cartilage provides a smooth surface required for the movement of the joints. Their damage arising from injury, disease, or overuse can impair the mobility of the joints, often leading to serious problems, until the disability. Unfortunately, cartilage is not able to recover and it is extremely difficult to replace.
Natural cartilage is composed of chondrocytes – cells, tightly adjacent to each other and produce the extracellular matrix, providing the density and elasticity of the fabric. The specialists tried to grow artificial cartilage by culturing cells on artificial frames. Recently, however, many of them switched on a frameless system, better reproducing natural conditions.
The authors cultured human chondrocytes in frameless system, allowing the cells to self-organize and attached to each other in a special way arranged by the device. After this, the cells were subjected to moderate stretching for several days.
Resulting as a result, the material composition and mechanical properties were close to natural cartilage. It contained a mixture of glycoproteins and collagen. Cross cross-linking between the molecules of the latter provided the strength and elasticity of the material. Similar results were obtained when using cells of cows.
Experiments on mice have demonstrated the stability of the material under physiological conditions. In the near future, the authors plan to implant lab-grown cartilage under load the joint and to perform its stability under stress.
Article Jennifer K. Lee et al. Tension stimulation drives tissue formation in scaffold-free systems published in the journal Nature Materials.
Eugene Ryabtsev
The portal of "Eternal youth" http://vechnayamolodost.ru on materials of the University of California – Davis: Artificial cartilage is under tension as strong as natural.