A new study shows that a type of stem cell found in umbilical cord blood, known as mesenchymal stem cells, has the potential to regenerate cartilage which has been damaged by injury or diseases such as osteoarthritis. Osteoarthritis is a common joint disease, affecting approximately 3.8% of people worldwide and almost 15% of people over the age of 60.

In the study, published online in the journal Stem Cells Translational Medicine, scientists obtained mesenchymal stem cells from human umbilical cord blood. They then supplemented the stem cells with a gel containing hyaluronic acid, a type of molecule normally found in cartilage and connective tissue. The mixture of stem cells and hyaluronic acid was transplanted into knees of miniature pigs which had sustained knee injuries. Twelve weeks after the treatment, macroscopic and microscopic analysis showed greater and more complete regeneration of cartilage compared with injured knees which did not receive the stem cell transplant. In the knees receiving the stem cells, the surface of the injury sites were relatively smooth as in a healthy joint, and cells in the treated area appeared similar to cells in the surrounding normal cartilage. Furthermore, there were no signs of rejection or infection in any of the animals.

Mesenchymal stem cells from cord blood are readily obtained and can be stored long-term, thus providing an attractive alternative to conventional knee and hip replacement surgeries. In recent years, the cartilage regeneration potential of mesenchymal stem cells has been investigated in rats and rabbits. The current study provides further support for such treatments using a larger animal that is physiologically similar to humans. According to the authors, the results in pigs provide a stepping stone to future clinical trials in humans.