September 7 : Rice University biomedical engineers have devised a novel method to grow cartilage from human embryonic stem cells.

The researchers say that their method may be used to grow replacement cartilage for the surgical repair of knee, jaw, hip, and other joints.

“Because native cartilage is unable to heal itself, researchers have long looked for ways to grow replacement cartilage in the lab that could be used to surgically repair injuries,” said lead researcher Kyriacos A. Athanasiou, the Karl F. Hasselmann Professor of Bioengineering.

“This research offers a novel approach for producing cartilage-like cells from embryonic stem cells, and it also presents the first method to use such cells to engineer cartilage tissue with significant functional properties,” Athanasiou added.

At first, the researchers used a series of stimuli to develop a method of converting the stem cells into cartilage cells, and, thereafter, they worked on a process for using the cartilage cells to make cartilage tissue.

The researchers found that cartilages that mimicked the different types of cartilage found in the human body—such as hyaline articular cartilage which is found in all joints, and fibrocartilage that are found in the knee meniscus and the jaw joint—could be created.

Athanasiou said that the results were exciting because they suggested that similar methods might be used to convert the stem cell-derived cartilage cells into robust cartilage sections, which could be of clinical usefulness.

The researchers are currently trying to uncover the secrets of the human body’s regenerative system, so that new ways of growing replacement tissues like muscle, skin, bone and cartilage could be found.

Athanasiou said that for the purpose of his research, embryonic stem cells have primary advantage over adult stem cells because the former can become any type of cell in the human body, while the latter can become only a limited number of cell types.

“Identifying a readily available cell source has been a major obstacle in cartilage engineering. We know how to convert adult stem cells into cartilage-like cells. The more problematic issue comes in trying to maintain a ready stock of adult stem cells to work with. These cells have a strong tendency to convert from stem cells into a more specific type of cell, so the clock is always ticking when we work with them,” he said.

The researcher said that his research team knew how to grow and maintain a stock of embryonic stem cells. He, however, admitted that there was no clear choice about which type of stem cell would work best for cartilage engineering.

“We don’t know the answer to that. It’s extremely important that we study all potential cell candidates, and then compare and contrast those studies to find out which works best and under what conditions. Keep in mind that these processes are very complicated, so it may well be that different types of cells work best in different situations,” Athanasiou said.

The study reported in the journal Stem Cells has been co-authored by two students, Eugene Koay and Gwen Hoben, both of whom are enrolled in the Baylor College of Medicine Medical Scientist Training Program, a joint program that allows students to concurrently earn their medical degree from Baylor while undertaking Ph.D. studies at Rice.

“Eugene and Gwen are both outstanding students. Each earned their undergraduate degree from Rice and each worked in my laboratory as undergraduate students. They have chosen to do this research because they think this may represent the future of regenerative medicine,” Athanasiou said. (ANI)