The quality of cartilage tissue depends upon its mechanical properties. In past years getting that right has proven to be challenging: growing cartilage cells is one thing, but forming the correct three-dimensional structures and extracellular matrix so that the resulting tissue can bear load is quite another. Nonetheless, progress has been made. To follow on from a recent demonstration of cartilage regeneration using induced pluripotent stem cells, here another group is using embryonic stem cells to regrow cartilage in situ:
Researchers have developed a protocol under strict laboratory conditions to grow and transform embryonic stem cells into cartilage cells (also known as chondrocytes). "This work represents an important step forward in treating cartilage damage by using embryonic stem cells to form new tissue, although it's still in its early experimental stages." During the study, the team analysed the ability of embryonic stems cells to become precursor cartilage cells. They were then implanted into cartilage defects in the knee joints of rats. After four weeks cartilage was partially repaired and following 12 weeks a smooth surface, which appeared similar to normal cartilage, was observed. Further study of this newly regenerated cartilage showed that cartilage cells from embryonic stem cells were still present and active within the tissue.
Developing and testing this protocol in rats is the first step in generating the information needed to run a study in people with arthritis. Before this will be possible more data will need to be collected to check that this protocol is effective and that there are no toxic side-effects. But researchers say that this study is very promising as not only did this protocol generate new, healthy-looking cartilage but also importantly there were no signs of any side-effects such as growing abnormal or disorganised, joint tissue or tumours. Further work will build on this finding and demonstrate that this could be a safe and effective treatment for people with joint damage.